CN111730060A - An atomizing spray disc, a method for preparing a narrow particle size alloy powder for additive manufacturing by gas atomization - Google Patents

Abstract

The invention discloses an atomizing spray disc and a method for preparing narrow particle size alloy powder for additive manufacturing by gas atomization, which belongs to the field of powder preparation and solves the technology of preparing narrow particle size alloy powder with low yield question. The atomizing spray disc includes a spray disc main body, a spray disc upper connecting body and a spray disc lower connecting body. A ring seam is formed between the spray disc lower connecting body and the spray disc upper connecting body or an annular hole is formed on the spray disc upper connecting body. A method for preparing a narrow particle size alloy powder for additive manufacturing by gas atomization, comprising the following steps: S1, for the preparation of fine particle size alloy powder with a median particle size of less than 60 μm, using a ring-slit spray disc; Coarse-grained alloy powder with a diameter of more than 60 μm is prepared by using a ring-hole spray disc; S2 determines the parameters of the spray disc; S3 determines the atomization process parameters. Using the atomizing spray disc of the present invention in the method of the present invention has the advantages of low cost and high efficiency for preparing high yield and narrow particle size alloy powder.

Description

An atomizing spray disc, a gas atomization preparation of narrow particle size alloy powder for additive manufacturing Methods

technical field

The invention relates to the technical field of powder preparation, and more particularly, to an atomizing spray disc and a method for preparing narrow particle size alloy powder for additive manufacturing by gas atomization.

Background technique

With the continuous application of additive manufacturing processes such as laser engineered net shaping, selective laser melting, cold spraying, and laser cladding in coal mines, automobiles, ships, aerospace and other fields, the demand for high-quality alloy powder materials is increasing. As the mainstream process of alloy powder preparation, the powder preparation volume of gas atomization process has reached 80% of the world's total powder production, and the proportion of some developed countries and regions is even greater. Gas atomization pulverizing technology is a non-equilibrium and fast process that uses high-pressure and high-speed gas to impinge on the molten metal flow, breaking the molten liquid into fine droplets and condensing them into powder particles. It has less environmental pollution, high powder sphericity, and oxygen content. low and fast cooling rates. However, due to the wide range of particle size distribution of the prepared alloy powder, the yield of the alloy powder within the relatively narrow particle size distribution range required is relatively low, that is, the yield of the alloy powder within the target narrow particle size range is low. Lower (hereinafter, the alloy powder in the narrow particle size range is simply referred to as the narrow particle size alloy powder). For example, the yield of GH4169 nickel-based alloy with a median particle size of 30 μm and a particle size distribution range of 15 to 53 μm for selective laser melting is only about 25%; the median particle size for laser cladding technology is 95 μm, The yield of FeNiCr stainless steel alloy powder with a particle size distribution ranging from 53 to 150 μm is only about 35%.

In order to improve the powder yield of the gas atomization process, the distribution range of the particle size of the alloy powder should be concentrated in the target particle size range as much as possible, that is, the preparation of narrow particle size alloy powder with high yield, so how to achieve the target aerosol The regulation of the particle size of the chemical powder is the key to reducing the production cost and improving the production efficiency of the gas atomization pulverizing technology, and it is also a technical problem that those skilled in the art are eager to solve. At present, most of the research in this area is to use a certain alloy raw material and optimize the gas atomization process to prepare the alloy powder that meets the production requirements, so as to obtain more alloy powder with the target particle size range.

The invention patent with the authorization announcement number CN106399863B discloses a laser additive 24CrNiMoRE alloy steel powder and a preparation method. The method utilizes the vacuum crucible induction melting gas atomization method, and by adjusting the gas atomization process parameters, prepares a spherical, fluid Good powder with controllable particle size range, low hollow sphere rate, strong and tough structure.

However, this method only discusses the influence of the process parameters in the gas atomization process in the preparation of alloy powder on the preparation result, but there are many factors affecting the yield of alloy powder within the target particle size range; Relevant methods and guidance are proposed for the preparation of high yields of alloy powders with different median diameters, so that the yields of alloy powders within the particle size range of the target median diameter are not high.

SUMMARY OF THE INVENTION

Aiming at the deficiencies of the prior art, the first object of the present invention is to provide an atomizing spray disc, which has the ability to realize the annular seam atomization spray disc and the ring through the installation and conversion of the upper connecting body of the spray disc and the lower connecting body of the spray disc. The fast switching between the orifice atomizing spray discs has the advantages of low cost of equipment for preparing narrow particle size alloy powder, more efficient preparation process, and the equipment is suitable for the preparation of narrow particle size alloy powder with different particle size ranges.

The second object of the present invention is to provide a method for preparing narrow particle size alloy powder for additive manufacturing by gas atomization. The advantage of high yield of narrow particle size alloy powder in the range.

In order to achieve the above-mentioned first purpose, the present invention provides the following technical scheme: comprising an annular spray disc body and a spray disc upper connecting body inserted in the spray disc body and closing the upper and lower ends of the spray disc body, a spray disc lower body A connecting body, the upper connecting body of the spray disc and the lower connecting body of the spraying disc are detachably and sealingly connected to the main body of the spraying disc, the upper connecting body of the spraying disc includes a feeding cylinder with a central hole, and the lower connecting body of the spraying disc is The outer peripheral surface of the lower part of the feed cylinder sleeved on the connecting body of the spray disc, an air cavity is formed between the main body of the spray disc, the upper connecting body of the spraying disc, and the lower connecting body of the spraying disc, and the peripheral surface of the spraying disc main body is provided with an inlet. Air port; an annular seam connecting the air cavity is formed between the outer peripheral surface of the lower part of the feeding cylinder and the lower connecting body of the spray disc, that is, the annular seam atomizing spray disc; or, the lower connecting body of the spray disc and the spray disc The lower part of the feeding cylinder of the upper connecting body is sealed and sleeved, and the lower end face of the feeding cylinder on the upper connecting body of the spray disc is provided with a plurality of through holes connecting the air cavity from bottom to top, and the through holes are annular and uniform around the central hole. Arrangement, that is, the ring hole atomizing spray disc.

By adopting the above technical solution, firstly, for the purpose of preparing alloy powders in different particle size ranges, the above-mentioned atomizing spray disc provides a usable spray disc; secondly, the process of using the existing gas atomization equipment The preparation of alloy powder with high yield cannot be achieved after the nozzle formed by the connecting body on the middle spray disc and the connecting body under the spray disc (that is, at the annular seam and the annular hole) is damaged. The price of some atomizing spray discs is relatively expensive, so the spray disc is made detachable, that is, after the connecting body on the spray disc and the connecting body under the spray disc are used together, the damage to the nozzle only needs to replace the connecting body on the different spray disc. It can be connected with the connecting body under the spray disc. In contrast, the volume of the connecting body on the spray disc and the connecting body under the spray disc is small, and the cost of preparing the connecting body on the spray disc and the connecting body under the spray disc is much lower than the cost of preparing the atomizing spray disc. The slot atomizing spray disk and the annular spray disk share the same spray disk body, which also greatly reduces the equipment cost in the production process.

Further, the longitudinal section of the connecting body on the spray disc is a "T"-like shape, the feeding cylinder is an inverted cone-shaped cylinder, and the upper edge of the feeding cylinder is radially protruded with an annular first upper a horizontal connection part; the lower connection body of the spray disc includes an inverted cone-shaped second cylinder, the second cylinder is arranged outside the feeding cylinder and a ring is formed between the outer wall of the feeding cylinder and the inner wall of the second cylinder sew.

By adopting the above technical solution, the replacement of the spray disc is realized through the detachment between the upper connecting body of the spraying disc, the lower connecting body of the spraying disc and the main body of the spraying disc, which is simple and convenient and has good sealing performance, and can meet the different median values in the actual production process. Production requirements for fine particle size alloy powders.

Further, the width d ₁ of the annular seam is 0.1-1.0 mm, the center-to-center distance L ₁ of the lower end of the annular seam is 5-40 mm, and the spray tip angle α ₁ of the annular seam spray disc is 15-60° .

By adopting the above technical scheme, under the adjustment of the above parameters, the yield of the obtained fine-grained alloy powder with a median diameter of less than 60 μm is higher; and the above-mentioned adjustment parameters of the annular seam provide a larger value for industrial production. The adjustment range makes it suitable for different industrial production requirements and has stronger practicability.

Further, the longitudinal section of the connecting body on the spray disc is an "I"-like shape, the feeding cylinder is in the shape of an inverted cone, and the upper edge of the feeding cylinder is radially provided with an annular second upper The horizontal connecting part, the outer surface of the lower part of the feeding cylinder is sleeved with an annular second lower horizontal connecting part; the maximum axial cross section of the second upper horizontal connecting part is larger than the largest axial cross section of the second lower horizontal connecting part, the The two upper horizontal connecting parts are detachably connected to the main body of the spray disc; the lower connecting body of the spray disc is cylindrical and is detachably connected between the main body of the spray disc and the second lower horizontal connecting part; the through hole is opened in the third The two lower horizontal connecting parts are close to the sleeve joints with the feeding cylinder; wherein, a sealing member is arranged between the lower connecting body of the spray disc and the second lower horizontal connecting part.

By adopting the above technical solution, the structure of the annular hole spray disc in the prior art is different from the structure of the annular hole spray disc in the prior art. The upper connecting body and the lower connecting body of the annular hole atomizing spray disc in the prior art The upper connecting body of the disc, the lower connecting body of the spraying disc and the main body of the spraying disc are detachably connected. The advantages of this arrangement are: first, the replacement of the spray disc is simple, convenient and has good sealing performance; secondly, after the nozzle is damaged, it is not necessary to directly replace the expensive spray disc, but only the upper connecting body of the spray disc and the lower connecting body of the spray disc can be replaced. Reduce costs; in addition, according to the production requirements of coarse-grained alloy powders with different median diameters in the actual production process, suitable upper and lower connectors of the spray disc can be adapted, which makes the equipment more practical. .

Further, the inner diameter d ₂ of the through hole is 0.1-2.0 mm, the spray apex angle α ₂ of the annular spray disc is 15-60°, and the hole center distance L ₂ at the lower end of the through hole is 5-40 mm , the number n of through holes is 4 to 40.

By adopting the above technical solution, under the above parameter adjustment, the obtained coarse-grained alloy powder with a median diameter of 60 μm or more has a higher yield. At the same time, the operation is simple, easy to realize industrial, and suitable for different industrial requirements.

For realizing the above-mentioned second purpose, the present invention provides the following technical solutions:

S1 According to the preparation requirements of different target median particle diameters of the narrow particle diameter alloy powder to be prepared, the type of atomizing spray disc to be used is selected, wherein, for the preparation of fine particle diameter alloy powder with a median particle diameter of 60 μm or less, A ring-slit atomizing spray disc is used; for the preparation of coarse-grained alloy powders with a median particle size of more than 60 μm, a ring-hole atomizing spray disc is used;

S2 makes the high-temperature molten metal enter the atomizing spray disc through the central hole, and at the same time, the inert gas is introduced from the air inlet. After adjusting the gas atomization parameters, the inert gas passes through the annular seam or through hole to generate alloy powder;

Wherein, the annular slot atomizing spray disc is the annular slot atomizing spray disc described in any one of claims 1-3, and the annular hole atomizing spray disc is the annular slot atomizing spray disc described in any one of claims 1, 4-5 Hole atomizing spray disc; the alloy is selected from one of GH4169, GH3625, NiCrAlY, 316L and FeNiCr type alloys, wherein the specific alloy composition of NiCrAlY type alloy is: Cr 21%～26.5%, Al4%～11%, Y 0.3%～1.3%, the balance is Ni; the specific alloy composition of FeNiCr alloy is: Ni 0.5%～6%, Cr 14%～18%, the balance is Fe; the specific composition of NiCoCrAlY alloy is: Co 20% ~ 24%, Cr 15% ~ 20%, Al 11% ~ 13%, Y 0.3% ~ 0.8%, the balance is Ni.

By adopting the above technical solution, under the same air pressure, the particle size of the alloy powder obtained after passing through the annular slot atomized spray disc is smaller than that of the alloy powder obtained after passing through the annular hole atomized spray disc. According to the preparation requirements of alloy powder, the present invention first selects different atomizing spray discs according to the particle size range of the target alloy powder to be obtained: the target median particle size of the alloy powder is used as the judgment standard, and the median particle size is more than 60 μm. The spray discs selected for the preparation of alloy powder and alloy powder with a median particle size of less than 60 μm are different; secondly, the equipment parameters of a specific spray disc are selected; the last consideration is the process parameters in the gas atomization process. Filter optimization. The above-mentioned method achieves the preparation of alloy powder with high yield in a narrow particle size range of coarse-grained alloy powder with a median particle size of 60 μm or more and fine-grained alloy powder with a median particle size of 60 μm or less . Moreover, by optimizing the above-mentioned relevant parameters, the yield of the target narrow particle size alloy powder is effectively improved.

Further, in the step S2, the pressure of the atomizing gas is 0.5-4.0 MPa, the temperature of the atomizing gas is 10-300 °C, the superheat degree of the high-temperature molten metal is 50-300 °C, and the flow rate of the high-temperature molten metal is 0.5-300 °C. 20kg/min.

By adopting the above-mentioned technical solution, it is more favorable to obtain alloy powder with a high yield and a target particle size range through industrial operation conditions suitable for the operation target.

Further, when using 316L alloy to prepare fine-grained alloy powder with a median particle size of 30 μm and a target particle size range of 15-53 μm, _a ring-slit spray disc is used to prepare the alloy powder. The selection range is 0.2-1.0 mm, the selection range of the hole center distance L ₁ at the lower end of the annular seam is 5-40 mm, the spray top angle α ₁ is 15-60°, and the atomizing gas pressure is 3.0-4.0 MPa, The atomizing gas temperature is 20～300℃, the superheat degree of the high temperature metal melt is 200～300℃, and the flow rate of the high temperature metal melt is 0.5～20kg/min;

When the GH4169 alloy is used to prepare fine-grained alloy powder with a median particle size of 30 μm and a target particle size range of 15-53 μm, a ring-slit spray disc is used to prepare the alloy powder, and the width d1 _of the ring-slit is 0.8 mm, The hole-to-center distance L1 at the lower end of the annular seam is ₁₄ mm, the spray apex angle α1 is ₃₀ °, the atomizing gas pressure is 3.0 MPa, the atomizing gas temperature is 20°C, and the superheat degree of the high-temperature metal melt is 200°C. ℃, the flow rate of high temperature molten metal is 10kg/min;

When the GH3625 alloy is used to prepare fine-grained alloy powder with a median particle size of 30 μm and a target particle size range of 15 to 53 μm, a ring-slit spray disc is used to prepare the alloy powder, and the width d ₁ of the annular slit is 0.8 mm, The hole-to-center distance L1 at the lower end _of the annular seam is ₁₂ mm, the spray apex angle α1 is 34°, the atomizing gas pressure is 3.5MPa, the atomizing gas temperature is 20°C, and the superheat degree of the high-temperature metal melt is 200°C. ℃, the flow rate of high temperature molten metal is 10kg/min;

When NiCrAlY alloy is used to prepare fine-grained alloy powder with a median particle size of 20 μm and a target particle size range of less than 38 μm, _a ring-slit spray disc is used to prepare the alloy powder. The hole-to-center distance L1 at the lower end _of the annular seam is 14mm, the spray top angle α1 is ₃₀ °, the atomizing gas pressure is 3.5MPa, the atomizing gas temperature is 20°C, and the superheat degree of the high-temperature metal melt is 200°C , the flow rate of high temperature metal melt is 10kg/min;

When the NiCoCrAlY alloy is used to prepare fine-grained alloy powder with a median particle size of 56 μm and a target particle size range of 38 to 75 μm, a ring-slit spray disc is used to prepare the alloy powder, and the width d ₁ of the annular slit is 0.6 mm, The hole-to-center distance L1 at the lower end of the annular seam is ₁₄ mm, the spray apex angle α1 is ₃₀ °, the atomizing gas pressure is 3.0 MPa, the atomizing gas temperature is 20°C, and the superheat degree of the high-temperature metal melt is 200°C. ℃, the flow rate of high temperature molten metal is 10kg/min;

When NiCrAlY alloy is used to prepare coarse-grained alloy powder with a median particle size of 67 μm and a target particle size range of 45 to 90 μm, a ring-hole spray disc is used to prepare the alloy powder. The ring-hole width d ₂ is 0.5 mm, so The hole-to _- center distance L2 at the lower end of the ring hole is 20mm, the spray top angle _α2 is 28°, the number of the ring holes is 30, the atomizing gas pressure is 3.5MPa, the atomizing gas temperature is 20°C, and the high temperature metal The superheat degree of the melt is 200℃, and the flow rate of the high temperature metal melt is 10kg/min;

When FeNiCr alloy is used to prepare coarse-grained alloy powder with a median particle size of 95 μm and a target particle size range of 53 to 150 μm, a ring-hole spray disc is used to prepare the alloy powder. The ring-hole width d ₂ is 0.5 mm, so The hole-to _- center distance L2 at the lower end of the ring hole is 20mm, the spray top angle _α2 is 28°, the number of the ring holes is 30, the atomizing gas pressure is 2.5MPa, the atomizing gas temperature is 20°C, and the high temperature metal The superheat degree of the molten metal was 200°C, and the flow rate of the high-temperature molten metal was 15 kg/min.

By adopting the above technical solution, before preparing the alloy powder, firstly select the spray disc to be used according to the preparation purpose, then select the optimized spray disc parameters, and finally optimize the gas atomization process. The yield of the target narrow particle size alloy powder prepared under the above-mentioned process conditions is relatively high.

Further, when the 316L alloy is used to prepare fine-grained alloy powder with a median particle size of 30 μm and a target particle size range of 15-53 μm, a ring-slit spray disc is used to prepare the alloy powder, and the width d1 _of the ring-slit is 0.2 mm, the hole-center distance L ₁ at the lower end of the annular seam is 16 mm, the spray apex angle α ₁ is 30°, the atomizing gas pressure is 3.0 MPa, the atomizing gas temperature is 20° C. The heat was 200°C, and the flow rate of the high-temperature molten metal was 10kg/min.

Further, the high-temperature molten metal is obtained by smelting metal raw materials and/or return materials, or by smelting master alloy rods.

By adopting the above technical solutions, the raw material of the high-temperature molten metal can be realized simply and efficiently.

To sum up, the present invention has the following beneficial effects:

First, according to the target particle size requirements of different alloy powders, the present invention can first select different atomizing spray discs, and screen the parameters of the atomizing spray discs, so as to carry out differential crushing for different preparation purposes, so that the narrow particles obtained can be obtained. The yield of diameter alloy powder is high and meets the special requirements of additive manufacturing technology for powder properties.

Second, the atomizing spray disc provided by the present invention enables the same atomizing equipment to meet the purpose of powder preparation in different particle size ranges by matching different upper connecting bodies of the spraying disc and lower connecting bodies of the spraying disc; at the same time, for Damaged and replaced spray discs are more convenient and equipment costs are reduced.

Description of drawings

Fig. 1 is the sectional view of the circular seam atomizing spray disc;

Fig. 2 is the sectional view of annular hole atomizing spray disc;

Fig. 3 is the topography under the SEM electron microscope of the fine-grained alloy powder prepared in Example 1;

FIG. 4 is a morphological diagram under the SEM electron microscope of the coarse-grained alloy powder prepared in Example 16. FIG.

In the figure, 1, the main body of the spray disc; 11, the connecting body on the spray disc is installed with an avoidance groove; 12, the lower connecting body of the spray disc is installed with an avoidance groove; 2, the upper connecting body on the spray disc; 21, the first upper horizontal connection part; 22, Feeding cylinder; 23. The second upper horizontal connecting part; 25. The second lower horizontal connecting part; , central hole; 5, air cavity; 6, air inlet; 7, annular seam; 8, through hole.

Detailed ways

The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

The powder particle size classification equipment is a vibrating screen and an air classifier. The vibrating screen is purchased from Xinxiang Hongsheng Machinery Co., Ltd., and the equipment model is: ￠800mm; the air classifier is purchased from Sichuan Juzi Supermicro Technology Co., Ltd., and the equipment model is JZF-200; gas atomization equipment was purchased from Handan Xurui Alloy Materials Co., Ltd., and the equipment model is: XR-PF(Q-2k)5.

As shown in FIG. 1 and FIG. 2 , the atomizing spray disc provided by the present invention includes an annular spray disc body 1 and a spray disc upper connection inserted in the spray disc body 1 and closing the upper and lower ends of the spray disc body 1 Body 2, lower connecting body 3 of spray disc, upper connecting body 2 of spray disc, lower connecting body 3 of spray disc are respectively detachable and sealing connection with the main body 1 of spray disc, further, connecting body 2 of spraying disc, connecting body 3 lower of spraying disc They are respectively connected with the main body 1 of the spray disc threadedly. The connecting body 2 on the spray disc includes a feeding cylinder 22 with a central hole 4 in the center, so that the high-temperature molten metal enters the atomizing spray disc through the central hole 4 of the feeding cylinder 22 . An air cavity 5 is formed between the spray disc main body 1 , the spray disc upper connecting body 2 and the spray disc lower connecting body 3 , and an air inlet 6 is opened on the peripheral surface of the spray disc body 1 along its radial direction. Between the feeding cylinder 22 and the lower connecting body 3 of the spray disc, a circular seam 7 (see FIG. 1 ) connecting the air cavity 5 and the central hole 4 is formed, or the lower end surface of the feeding cylinder 22 is provided with several communicating air cavities 5 from bottom to top. and through holes 8 (see FIG. 2 ); seals are provided between the upper connecting body 2 of the spray disc and the spray disc main body 1 and between the spray disc lower connecting body 3 and the spray disc body 1 .

Specifically, as shown in FIG. 1 , the atomizing spray disc is a circular seam atomizing spray disc, the spray disc main body 1 is a cylindrical body, the longitudinal section of the connecting body 2 on the spray disc is a "T"-like shape, and the feeding cylinder 22 is Inverted cone-shaped, the upper edge of the feeding cylinder 22 is radially protruded with an annular first upper horizontal connecting part 21 , the feeding cylinder 22 and the first upper horizontal connecting part 21 are coaxially arranged and integrally formed.

Preferably, a ring-shaped connecting body mounting avoidance groove 11 on the spray disk is provided from the upper end surface of the cylindrical spray disk main body 1 near the inside thereof. After extending downward, it is opened and communicated with the inside of the spray disc main body 1 . The first upper horizontal connecting portion 21 is screwed to the spray pan body 1 , and at this time, the outer edge of the first upper horizontal connecting portion 21 is located in the mounting and avoiding groove 11 of the connecting body on the spray pan. Further preferably, a sealing ring is installed between the installation avoidance groove 11 of the connecting body on the spray disc and the spray disc main body 1 to seal the connection between the spray disc main body 1 and the connecting body 2 on the spray disc, and at the connection between the two. There are bolts at the place to further connect the two (the sealing ring and the bolts are not shown in the figure).

The lower connecting body 3 of the spray disc includes an inverted cone-shaped second cylinder 31, and the second cylinder 31 is sleeved outside the lower end of the feeding cylinder 22, so that the outer wall of the feeding cylinder 22 and the second cylinder 31 The above-mentioned annular seam 7 is formed between the inner walls of the Further, the width d1 of the annular seam ₇ is 0.1-1.0 mm, the center-to-center distance L1 of the lower end of the annular seam ₇ is 5-40 mm, and the spray tip angle α1 _of the annular seam spray disc is 15-60°.

Similar to the structure of the connecting body installation avoidance groove 11 on the spray disc, there is an annular spray disc lower connection body installation avoidance groove 12 on the lower surface of the spray disc main body 1. The lower surface of 1 extends upward and is opened to communicate with the interior of the spray disc main body 1 . The side of the installation avoidance groove 12 of the lower connecting body of the spray disc is provided with an inner thread, and the outer peripheral surface of the lower connecting body 3 of the spray disc is provided with an external thread. threaded connection, at this time the outer edge of the lower connecting body 3 of the spray disc is located in the installation avoidance groove 12 of the lower connecting body of the spray disc, and the lower connecting body 3 of the spray disc and the main body 1 of the spray disc are sealed and connected by the sealing ring and the bolt (not shown in the figure). seals and bolts shown).

As shown in Fig. 2, the atomizing spray disc is an annular atomizing spray disc, the longitudinal section of the connecting body 2 on the spray disc is an "I"-like shape, the feeding cylinder 22 is an inverted cone-shaped cylinder, and the feeding cylinder 22 The upper edge of the feed cylinder 22 is radially protruded with an annular second upper horizontal connecting portion 23, and the lower edge of the feeding cylinder 22 is radially protruded with an annular second lower horizontal connecting portion 25. The connecting portion 23 , the feeding cylinder 22 and the second lower horizontal connecting portion 25 are coaxially disposed and integrally formed. The maximum axial cross-section of the second upper horizontal connecting portion 23 is larger than the maximum axial cross-section of the second lower horizontal connecting portion 25 , and the second upper horizontal connecting portion 23 is screwed with the spray disc main body 1 . The spray pan lower connecting body 3 is cylindrical and is detachably connected between the spray pan main body 1 and the second lower horizontal connecting part 25 . Specifically, the inner peripheral surface and the outer peripheral surface of the lower connecting body 3 of the spray disc are provided with threads, and the outer peripheral surface of the connecting end of the second lower horizontal connecting portion 25 and the lower connecting body 3 of the spray disc is provided with external threads, and the lower connecting body of the spray disc is provided with external threads. 3 and the second lower horizontal connecting part 25 are screwed together, and the lower connecting body 3 of the spray disc is screwed with the main body 1 of the spray disc.

Further, the lower connecting body 3 of the spray disc is provided with a second lower horizontal connecting part installation avoidance groove 251, and the second lower horizontal connecting part installation avoidance groove 251 extends downward from the upper surface of the lower connecting body 3 of the spray disc and opens. form and communicate with the interior of the lower connecting body 3 of the spray disc. After the lower connecting body 3 of the spray pan and the second lower horizontal connecting part 25 are screwed together, the outer edge of the second lower horizontal connecting part 25 is located in the installation and avoiding groove 251 of the second lower horizontal connecting part. Further preferably, a sealing ring is provided between the second lower horizontal connecting part 25 and the lower connecting body 3 of the spray disc for sealing the two, and the two are connected by bolts.

The through holes 8 are opened in the second lower horizontal connecting part 25 near the feeding cylinder 22 . The through holes 8 are evenly opened from bottom to top along the peripheral surface of the feeding cylinder 22 , and the through holes 8 communicate with the air cavity 5 . The inner diameter d ₂ of the through hole 8 is 0.1 to 2.0 mm, the spray apex angle α ₂ of the annular spray disc is 15 to 60°, the center distance L ₂ of the lower end of the through hole 8 is 5 to 40 mm, and the number n of the through holes 8 There are 4 to 40 through holes, and the through holes 8 are arranged in a circle around the peripheral surface of the feeding cylinder 22 .

Example 1

A method for preparing narrow particle size alloy powder for additive manufacturing based on entropy reduction regulation, comprising the following steps:

(1) Alloy smelting: The GH4169 nickel-based alloy bar is placed in the smelting chamber for vacuum electrode induction melting, and the melting temperature is 1520 ° C. By controlling the heating of the induction coil, the lower end of the bar gradually melts to form a continuous and stable metal melt. The melt superheat degree is 200℃, and the alloy melt flow rate is 6kg/min.

(2) Atomization powder production: According to the target particle size requirements of the alloy powder with a median particle size of 30 μm and a particle size distribution range of 15 to 53 μm for the selective laser melting technology, the annular slot atomization spray disc is selected, and the annular slot width d ₁ is 0.8 mm, the spray top angle α ₁ is 30°, and the hole center distance L ₁ at the lower end of the annular seam is 14 mm;

(3) The high-temperature molten metal enters the annular seam atomizing spray disc through the central hole 4, and at the same time, the inert gas is introduced from the air inlet 6, so that the inert gas enters the air cavity 5, and the gas atomization parameters are adjusted: the atomizing gas is high Pure argon gas, its purity is 99.999%; the atomization crushing pressure is 3.0MPa, and the atomization gas temperature is 20 ℃; the alloy melt is sprayed from the annular gap 7, and under the crushing and cooling action of high-purity argon gas, GH4169 is obtained Nickel-based alloy powder.

Example 2-19

The difference between Examples 2-19 and Example 1 lies in the different alloy raw materials, different spray discs, different spray disc structural parameters and different atomization process parameters when preparing the alloy powder, as shown in Table 1 for details.

Table 1 Equipment and process conditions for preparing alloy powder of Examples 1-19

Among them, the alloys used in Examples 1-2 and 4-15 are commercially available; the superalloy melt is obtained by smelting the master alloy rod. The specific components and proportions of the NiCrAlY alloy in Example 3 and Example 17 are: Ni is the balance, Cr: 23%, Al: 8%, Y: 0.8%; , chromium, niobium and other raw materials are added into the smelting crucible according to the alloy ratio for smelting to obtain FeNiCr stainless steel alloy melt. The alloy composition ratio is: Ni: 3%, Cr: 16%, and Fe is the balance; NiCoCrAlY in Example 18 The specific components are: Co: 23%, Cr: 18%, Al: 12%, Y: 0.6%, and the balance is Ni.

Comparative Examples 1-6

The difference between Comparative Examples 1-6 and Example 1 lies in the different alloy raw materials, different spray discs, different spray disc structural parameters and different atomization process parameters when preparing the alloy powder, as shown in Table 2 for details.

Table 2 Equipment and process conditions for preparing alloy powder of Comparative Examples 1-6

Wherein, the alloys of Comparative Example 1 and Comparative Examples 5-6 are commercially available, the specific composition of the FeNiCr alloy of Comparative Example 2 is the same as that of Example 16, the specific composition of the NiCrAlY alloy of Comparative Example 3 is the same as that of The specific composition of the NiCoCrAlY alloy is the same as that of Example 18.

(1) Detection of the yield of alloy powder

The particle size classification of the alloy powders collected by atomization in Example 1-1-2, Example 4-15, Comparative Example 5-6, and Comparative Example 1 was carried out by air classification, so as to obtain the particle size for selective laser melting technology. For the alloy powder with a distribution range of 15-53 μm, the yield results of the alloy powder are shown in Table 3. The particle size classification of the alloy powder collected by atomization in Example 16 and Comparative Example 2 was carried out by vibrating sieving method to obtain an alloy powder with a particle size distribution range of 53-150 μm for laser cladding technology. The results are shown in Table 3. The alloy powder of Example 3 was subjected to particle size classification by vibrating sieving, thereby obtaining alloy powder with a particle size distribution range of less than 38 μm for low-pressure plasma spraying technology. The collected alloy powders of Examples 17-18 and Comparative Examples 3-4 were respectively subjected to particle size classification by vibrating sieving, thereby obtaining alloy powders with corresponding particle size distribution ranges for atmospheric plasma spraying technology. The results are shown in Table 3.

Table 3 Yields of powder alloys within the corresponding particle size ranges of the alloy powders prepared in Examples 1-18 and Comparative Examples 1-6

From the results in Table 3, it is shown by the data of Comparative Examples 4-15 and Comparative Example 1 (or Comparative Example 18 and Comparative Example 4) that the same alloy is selected to prepare alloy powders with a target particle size range of the target median particle size. , when the target median particle size is less than 60 μm, the annular slot spray disc should be selected first, and then the optimal parameters of the annular slot spray disc and the optimal parameters of aerosolization should be obtained by screening. The yield of alloy powder in the target particle size range under the particle size is relatively high: the 316L alloy is used as the raw material to prepare alloy powder with a median particle size of about 30 μm and a powder particle size of 15 to 53 μm. The yield of alloy powder within the range is 31-45%; if the ring-hole spray disc is selected first, the 316L alloy is used as the raw material to prepare alloy powder with a median particle size of about 30 μm and a powder particle size of 15-53 μm. The yield was 25%.

Using NiCoCrAlY alloy as raw material to prepare alloy powder with a median particle size of about 56 μm and a powder particle size of 38 to 75 μm, the yield of alloy powder within this particle size range prepared by using a ring-slit spray disc is 43%; The ring-hole spray disc uses NiCoCrAlY alloy as raw material to prepare alloy powder with a median particle size of about 57 μm and a powder particle size of 38-75 μm, and the yield of the alloy powder is 35%.

The data of comparative example 16 and comparative example 2 (or comparative example 17 and comparative example 3) show that the same alloy is selected to prepare alloy powder with the target particle size range of the target median particle size, when the target median particle size is greater than 60 μm When , the ring-hole spray disc should be selected first, and then the optimal parameters of the ring-hole spray disc and the optimal parameters of gas atomization should be obtained by screening. Using this method, the alloy with the target particle size range under the target median particle size can be prepared. High powder yield: FeNiCr alloy is used as raw material to prepare alloy powder with a median particle size of about 95 μm and a powder particle size of 53 to 150 μm, and the yield of alloy powder within this particle size range prepared by ring-hole spray disc If the ring-slit spray disc is selected first, and FeNiCr alloy is used as raw material to prepare alloy powder with a median particle size of about 95 μm and a powder particle size of 53-150 μm, the yield of alloy powder is 42%.

Using NiCrAlY alloy as raw material to prepare alloy powder with a median particle size of about 67 μm and a powder particle size of 53 to 150 μm, the yield of alloy powder in this particle size range prepared by using a ring-hole spray disc is 49%; The ring-slit spray disc uses NiCrAlY alloy as raw material to prepare alloy powder with a median particle size of about 68 μm and a powder particle size of 53-150 μm, and the yield of the alloy powder is 32%.

Therefore, it is very important to first select the spray disc to be used before preparing the alloy powder.

(2) Testing of other properties of alloy powder

Other properties of the alloy powders for selective laser melting prepared in Examples 1-2, Example 4 and Comparative Example 1 were tested, wherein the detection of the bulk density of the alloy powders was based on the national standard GB/T 1479.1- 2011; the fluidity of alloy powders was tested according to the national standard GB/T1482-2010; the angle of repose of alloy powders was tested according to the national standard GB/T16913-2008; the tensile strength, yield strength and The detection of elongation after fracture is carried out according to the national standard GB/T 228-2002, and the results are shown in Table 4.

Table 4 Performance testing of alloy powders prepared in Examples 1-2, Example 4 and Comparative Example 1

Combining the results in Table 4, it can be seen that the alloy powders of Examples 1-2 and 4 are used in the selective laser melting technology to prepare and form products with uniform structure, compact structure and excellent mechanical properties.

Other properties of the alloy powders for laser cladding prepared in Example 16 and Comparative Example 2 were tested, wherein the detection of the bulk density of the alloy powders was carried out according to the national standard GB/T1479.1-2011; The testing of powder fluidity is carried out according to the national standard GB/T1482-2010; the testing of the hardness of the cladding layer of the laser cladding coating is carried out according to the national standard YS/T 541-2006; the detection of the thickness of the cladding layer of the laser cladding coating According to the national standard GB/T6463-2005; the neutral salt spray corrosion test of the laser cladding coating is carried out according to the national standard GB/T 2423.17-2008, and the results are shown in Table 5.

Table 5 Performance testing of alloy powders prepared in Example 16 and Comparative Example 2

Combined with the data in Table 5, it can be seen that the FeNiCr stainless steel alloy powder prepared in this example meets the special requirements of laser cladding technology for powder particle size.

Other properties of the alloy powders for atmospheric plasma spraying prepared in Examples 17-18 and Comparative Examples 3-4 were tested, wherein the detection of the bulk density of the alloy powders was based on the national standard GB/T1479.1-2011 The detection of the fluidity of the alloy powder was carried out according to the national standard GB/T1482-2010, and the results are shown in Table 6.

Table 6 Performance testing of alloy powders prepared in Examples 17-18

Test items Bulk density (g/cm³) Mobility (s/50g) Sphericity Example 17 3.84 13.75 95 Example 18 3.87 15.93 94 Comparative Example 3 3.92 13.92 97 Comparative Example 4 3.83 15.87 93

Meanwhile, FIG. 1 provides the SEM image of the fine-grained alloy powder prepared in Example 1, and FIG. 2 provides the SEM image of the coarse-grained alloy powder prepared in Example 16. The alloy powder shown in the figure has good sphericity.

This specific embodiment is only an explanation of the present invention, and it does not limit the present invention. Those skilled in the art can make modifications without creative contribution to the present embodiment as required after reading this specification, but as long as the rights of the present invention are used All claims are protected by patent law.

Claims (10)

1. An atomizing spray disk comprises an annular spray disk main body (1), and a spray disk upper connecting body (2) and a spray disk lower connecting body (3) which are inserted into the spray disk main body (1) and seal the upper end and the lower end of the spray disk main body (1), wherein the spray disk upper connecting body (2) and the spray disk lower connecting body (3) are detachably and hermetically connected with the spray disk main body (1), the spray disk upper connecting body (2) comprises a feeding cylinder (22) with a central hole (4), the spray disk lower connecting body (3) is sleeved on the outer peripheral surface of the lower part of the feeding cylinder (22) of the spray disk upper connecting body (2), an air cavity (5) is formed among the spray disk main body (1), the spray disk upper connecting body (2) and the spray disk lower connecting body (3), and an air inlet (6) is formed on the peripheral surface of the spray disk main body (1); the device is characterized in that a circular seam (7) communicated with the air cavity (5) is formed between the peripheral surface of the lower part of the feeding cylinder (22) and the lower connecting body (3) of the spray disk, namely the circular seam atomization spray disk; or the lower connecting body (3) of the spray disk and the lower part of the feeding cylinder (22) of the upper connecting body (2) of the spray disk are sleeved in a sealing way, the lower end surface of the feeding cylinder (22) on the upper connecting body (2) of the spray disk is provided with a plurality of through holes (8) communicated with the air cavity (5) from bottom to top, and the through holes (8) are uniformly distributed in an annular shape around the central hole (4), namely the annular atomizing spray disk.

2. The atomizing spray disk of claim 1, characterized in that the longitudinal section of the upper connecting body (2) of the spray disk is similar to a T shape, the feeding cylinder (22) is in an inverted cone shape, and the upper edge of the feeding cylinder (22) is provided with a circular first upper horizontal connecting part (21) in a protruding way along the radial direction; the lower spray disk connecting body (3) comprises an inverted conical second cylinder body (31), the second cylinder body (31) is arranged outside the feeding cylinder (22), and a circular seam (7) is formed between the outer wall of the feeding cylinder (22) and the inner wall of the second cylinder body (31).

3. Atomizing spray disk according to claim 2, characterized in that the width d of the circumferential slot (7)₁0.1-1.0 mm, and the hole center distance L of the lower end of the circular seam (7)₁Is 5-40 mm, and the jet vertex angle α of the circular seam spray disk₁Is 15 to 60 degrees.

4. The atomizing spray disk of claim 1, wherein the longitudinal section of the upper connecting body (2) of the spray disk is in an I shape like the Chinese character 'er', the feeding cylinder (22) is in an inverted conical cylinder shape, the edge of the upper part of the feeding cylinder (22) is provided with a circular second upper horizontal connecting part (23) in a protruding mode along the radial direction, and the outer surface of the lower part of the feeding cylinder (22) is sleeved with a circular second lower horizontal connecting part (25); the maximum axial section of the second upper horizontal connecting part (23) is larger than that of the second lower horizontal connecting part (25), and the second upper horizontal connecting part (23) is detachably connected with the spray disc main body (1); the spray plate lower connecting body (3) is cylindrical and is detachably connected between the spray plate main body (1) and the second lower horizontal connecting part (25); the through hole (8) is formed in the second lower horizontal connecting part (25) close to the sleeving joint of the second lower horizontal connecting part and the feeding cylinder (22); and a sealing element is arranged between the spray disk lower connecting body (3) and the second lower horizontal connecting part (25).

5. Atomizing spray disk according to claim 4, characterized in that the inner diameter d of the through-opening (8)₂Is 0.1-2.0 mm, and the spray vertex angle α of the annular hole spray disk₂Is 15-60 degrees, and the hole center distance L of the lower end of the through hole (8)₂5-40 mm, and 4-40 through holes (8).

6. A method for preparing alloy powder with narrow particle size for additive manufacturing by gas atomization is characterized by comprising the following steps:

s1, selecting the type of the atomizing spray disk to be used according to the preparation requirements of different target median diameters of the narrow-particle-diameter alloy powder to be prepared, wherein the circular seam atomizing spray disk is adopted for the preparation of the fine-particle-diameter alloy powder with the median diameter of less than 60 mu m; aiming at the preparation of coarse-grain alloy powder with the median grain diameter of more than 60 mu m, an annular hole atomizing spray disk is adopted;

s2, enabling the high-temperature molten metal to enter the atomizing spray disk through the central hole (4), simultaneously introducing inert gas from the gas inlet (6), and after gas atomization parameters are adjusted, enabling the inert gas to pass through the circular seam (7) or the through hole (8) to generate alloy powder;

wherein, the annular seam atomizing spray disk is the annular seam atomizing spray disk of any one of claims 1 to 3, and the annular hole atomizing spray disk is the annular hole atomizing spray disk of any one of claims 1 and 4 to 5; the alloy is selected from one of GH4169, GH3625, NiCrAlY, 316L and FeNiCr type alloy, wherein the specific alloy components of the NiCrAlY type alloy are as follows: 21-26.5% of Cr, 4-11% of Al, 0.3-1.3% of Y and the balance of Ni; the FeNiCr type alloy comprises the following specific alloy components: 0.5-6% of Ni, 14-18% of Cr and the balance of Fe; the NiCoCrAlY alloy comprises the following specific components: 20-24% of Co, 15-20% of Cr, 11-13% of Al, 0.3-0.8% of Y and the balance of Ni.

7. The method for preparing alloy powder with narrow particle size for additive manufacturing according to claim 6, wherein the atomizing gas pressure in step S2 is 0.5-4.0 MPa, the atomizing gas temperature is 10-300 ℃, the superheat degree of the high-temperature molten metal is 50-300 ℃, and the flow rate of the high-temperature molten metal is 0.5-20 kg/min.

8. The method for preparing alloy powder with narrow particle size for additive manufacturing by gas atomization according to claim 6,

when 316L alloy is adopted to prepare fine-grain-size alloy powder with the median grain size of 30 mu m and the target grain size range of 15-53 mu m, a circular seam spray disk is adopted to prepare the alloy powder, and the width d of the circular seam₁The selection range of (1) is 0.2-1.0 mm, and the hole center distance L of the lower end of the circular seam₁The selection range of (A) is 5-40 mm, and the jet vertex angle is α₁15-60 degrees, the pressure of atomizing gas is 3.0-4.0 MPa, the temperature of atomizing gas is 20-300 ℃, the superheat degree of high-temperature molten metal is 200-300 ℃, and the flow rate of the high-temperature molten metal is 0.5-20 kg/min;

when GH4169 alloy is adopted to prepare fine-grain-size alloy powder with the median grain size of 30 mu m and the target grain size range of 15-53 mu m, a circular seam spray disk is adopted to prepare the alloy powder, and the width d of the circular seam₁Is 0.8mm, and the hole center distance L of the lower end of the circular seam₁At 14mm, the spray apex angle α₁At 30 degrees, the pressure of atomizing gas is 3.0MPa, and the atomization is carried outThe gas temperature is 20 ℃, the superheat degree of the high-temperature molten metal is 200 ℃, and the flow rate of the high-temperature molten metal is 10 kg/min;

when GH3625 alloy is used for preparing fine-grain-size alloy powder with the median grain size of 30 mu m and the target grain size range of 15-53 mu m, a circular seam spray disk is used for preparing the alloy powder, and the width d of the circular seam₁Is 0.8mm, and the hole center distance L of the lower end of the circular seam₁12mm, the spray apex angle α₁At 34 degrees, the pressure of atomizing gas is 3.5MPa, the temperature of atomizing gas is 20 ℃, the superheat degree of high-temperature molten metal is 200 ℃, and the flow rate of the high-temperature molten metal is 10 kg/min;

when NiCrAlY alloy is used for preparing fine-grain alloy powder with the median grain diameter of 20 mu m and the target grain size range of less than 38 mu m, a circular seam spray disk is used for preparing the alloy powder, and the width d of the circular seam₁Is 0.6mm, and the hole center distance L of the lower end of the circular seam₁At 14mm, the spray apex angle α₁At 30 degrees, the pressure of atomizing gas is 3.5MPa, the temperature of atomizing gas is 20 ℃, the superheat degree of high-temperature molten metal is 200 ℃, and the flow rate of the high-temperature molten metal is 10 kg/min;

when NiCoCrAlY alloy is adopted to prepare fine-grain alloy powder with the median grain diameter of 56 mu m and the target grain size range of 38-75 mu m, a circular seam spray disk is adopted to prepare the alloy powder, and the width d of the circular seam₁Is 0.6mm, and the hole center distance L of the lower end of the circular seam₁At 14mm, the spray apex angle α₁At 30 degrees, the pressure of atomizing gas is 3.0MPa, the temperature of atomizing gas is 20 ℃, the superheat degree of high-temperature molten metal is 200 ℃, and the flow rate of the high-temperature molten metal is 10 kg/min;

when NiCrAlY alloy is adopted to prepare coarse-grain-size alloy powder with the median grain size of 67 mu m and the target grain size range of 45-90 mu m, an annular hole spray disk is adopted to prepare the alloy powder, and the width d of the annular hole₂Is 0.5mm, and the hole center distance L of the lower end of the annular hole₂Is 20mm, and the jet vertex angle is α₂At 28 degrees, the number of the annular holes is 30, the pressure of atomizing gas is 3.5MPa, the temperature of the atomizing gas is 20 ℃, the superheat degree of high-temperature molten metal is 200 ℃, and the flow rate of the high-temperature molten metal is 10kg/min；

When FeNiCr alloy is adopted to prepare coarse-grain-size alloy powder with the median grain size of 95 microns and the target grain size range of 53-150 microns, an annular hole spraying disc is adopted to prepare the alloy powder, and the width d of the annular hole₂Is 0.5mm, and the hole center distance L of the lower end of the annular hole₂Is 20mm, and the jet vertex angle is α₂The temperature is 28 degrees, the number of the annular holes is 30, the pressure of atomizing gas is 2.5MPa, the temperature of the atomizing gas is 20 ℃, the superheat degree of high-temperature molten metal is 200 ℃, and the flow rate of the high-temperature molten metal is 15 kg/min.

9. The method for preparing alloy powder with narrow particle size for additive manufacturing through gas atomization according to claim 8, wherein when 316L alloy is used for preparing alloy powder with fine particle size, the median particle size of which is 30 μm and the target particle size range of which is 15-53 μm, the preparation of the alloy powder is carried out through a circular seam spray disk, and the width d of the circular seam is₁Is 0.2mm, and the hole center distance L of the lower end of the circular seam₁16mm, the spray apex angle α₁The temperature is 30 degrees, the pressure of atomizing gas is 3.0MPa, the temperature of atomizing gas is 20 ℃, the superheat degree of high-temperature molten metal is 200 ℃, and the flow rate of the high-temperature molten metal is 10 kg/min.

10. The method for preparing alloy powder with narrow particle size for additive manufacturing through gas atomization according to claim 1, wherein the high-temperature molten metal is obtained after smelting a metal raw material and/or a return material, or is obtained by smelting a master alloy rod.

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