Nickel-based alloy composite powder, method for preparing the same, and use thereof

Abstract

The present application relates to additive manufacturing technical field, especially to a kind of nickel-based alloy composite powder for eliminating nickel-based alloy additive manufacturing crack and its preparation method and application.The nickel-based alloy composite powder described in the present application is obtained by proportionally mixing nickel-based alloy GH3230 powder with base particle size of 15-150 μm and functional powder containing Mo and C element with particle size of 0.05-5 μm.The nickel-based alloy composite powder provided in the present application has the function of eliminating nickel-based alloy additive manufacturing crack;And other new elements are not introduced in nickel-based alloy, which is beneficial to the rapid batch application of product.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and in particular to a nickel-based alloy composite powder for eliminating cracks in nickel-based alloy additive manufacturing, its preparation method, and its application. Background Technology

[0002] The demand for additively manufactured high-temperature alloy components is becoming increasingly urgent for major engineering projects such as aero-engines, hypersonic vehicles, and heavy-lift rockets. Currently, the nickel-based high-temperature alloys that have achieved or are close to engineering applications are still mainly traditional cast and forged alloy grades such as GH3536, GH3625, and GH4169. These alloys generally have good weldability and good additive manufacturing processability, but their high-temperature performance is limited and cannot meet the needs of future high-generation aerospace power applications. On the other hand, high-temperature alloys with higher temperature resistance and higher performance, such as GH3230, IN738 (K438), and CM247LC (K447), are affected by high solid solution alloying and γ′ phase content. Under the rapid solidification and large thermal gradient of the additive manufacturing process, various metallurgical defects such as cracks are common in the formed samples. These defects will further affect the mechanical properties of the samples and components, especially the high-temperature creep and fatigue properties of the alloy, thus hindering the engineering application of these alloys.

[0003] Based on current application needs, exploring the additive manufacturing applicability of higher alloying and higher performance high-temperature alloys, and preparing high-density, crack-free high-temperature alloy components through material design optimization, has become an important research direction. Existing technologies mainly suppress forming cracks by adjusting the alloy composition, such as by adding other elements or changing the elemental composition ratios. However, this method usually introduces other elements into the alloy or alters the initial composition range, affecting the mass production and application of the alloy.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a nickel-based alloy composite powder for eliminating manufacturing cracks in nickel-based alloy additives, its preparation method, and its applications.

[0006] Specifically, the technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention provides a nickel-based alloy composite powder, which is composed of a base powder and a functional powder; the base powder is nickel-based alloy GH3230 powder with a particle size of 15-150 μm; the functional powder is MoC compound powder with a particle size of 0.05-5 μm, or a mixed powder composed of C elemental powder and Mo elemental powder; the amount of the functional powder added to the nickel-based alloy composite powder is 0.5% to 3%.

[0008] The nickel-based alloy powder provided by this invention has the function of eliminating forming cracks in nickel-based alloy additive manufacturing. Specifically, it is achieved by mixing in a portion of the carbon (C) and molybdenum (Mo) elements from the nickel-based alloy in the form of additional small-particle powder (such as MoC powder). During the additive manufacturing process, this forms more M23C6 type carbides that are continuously distributed in a film at the grain boundaries, filling the grain boundaries, eliminating forming cracks in the nickel-based superalloy, and improving the forming density of the material. Furthermore, this invention only changes the form of C and Mo elements in the powder, without introducing other new elements into the nickel-based alloy. After mixing, the total C and Mo element composition can be controlled within the original range, which is beneficial for the rapid mass production and application of the product.

[0009] Preferably, the nickel-based alloy GH3230 powder comprises the following components in weight percentage: C: 0.05%~0.15%; Cr: 20.00%~24.00%; Co: ≤5.00%; W: 13.00%~15.00%; Mo: 1.00%~3.00%; Al: 0.20%~0.50%; Ti: ≤0.10%; Fe: ≤3.00%; B: ≤0.015%; Si: 0.25%~0.75%; Mn: 0.30%~1.00%; La: 0.005%-0.05%; balance Ni.

[0010] Preferably, in the nickel-based alloy composite powder, the total mass percentage of C element does not exceed 0.15% and the total mass percentage of Mo element does not exceed 3.00%.

[0011] More preferably, the functional powder is MoC compound powder; the MoC powder is uniformly coated on the surface of the nickel-based alloy GH3230 powder by mixing.

[0012] More preferably, the particle size of the MoC compound powder is 50±10nm; the particle size of the nickel-based alloy GH3230 powder is 15-53μm.

[0013] Secondly, the present invention provides a method for preparing the nickel-based alloy composite powder, which includes the step of mixing a base powder and a functional powder. The mixing speed is 20±5 rpm / min, and the mixing time is 6±3 h.

[0014] Thirdly, the present invention provides a nickel-based alloy, which is obtained by additive manufacturing from the aforementioned nickel-based alloy composite powder.

[0015] Preferably, the additive manufacturing method is selective laser melting, directional energy deposition, or electron beam melting.

[0016] More preferably, the additive manufacturing method is selective laser melting; wherein the laser power is 100-300W, the scanning speed is 600-1200mm / s, the scanning spacing is 0.09-0.12μm, and the powder layer thickness is 30-80μm.

[0017] The nickel-based alloy provided by this invention has M23C6 type carbides distributed in a continuous film (rather than a dotted distribution) at its grain boundaries, which can eliminate forming cracks in nickel-based superalloys and improve the forming density of the material.

[0018] Beneficial effects:

[0019] This invention provides a nickel-based alloy composite powder, its preparation method, and its application. The nickel-based alloy composite powder is obtained by mixing nickel-based alloy GH3230 powder with a particle size of 15-150 μm and functional powder containing Mo and C elements with a particle size of 0.05-5 μm in a specific ratio. The nickel-based alloy composite powder provided by this invention has the function of eliminating manufacturing cracks in nickel-based alloys; and it does not introduce other new elements into the nickel-based alloy, which is beneficial for the rapid mass production and application of the product. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be described below.

[0021] Figure 1 The image shows the morphology of GH3230 powder mixed with 1% MoC powder in Example 1.

[0022] Figure 2 The metallographic model of GH3230+1%MoC in Example 1 is shown.

[0023] Figure 3 The microstructure of GH3230+1%MoC in Example 1 (white is M23C6 carbide).

[0024] Figure 4 The metallographic model of GH3230+1.5%MoC in Example 2 is shown.

[0025] Figure 5 The metallographic model of GH3230+1.5%MoC in Example 3 is shown.

[0026] Figure 6 Metallographic model of GH3230 alloy formed by laser selective melting in Comparative Example 1.

[0027] Figure 7 The microstructure of GH3230 in Comparative Example 1 is shown (white is M23C6 carbide).

[0028] Figure 8 Metallographic model of GH3230 alloy formed by laser selective melting in Comparative Example 2. Detailed Implementation

[0029] This invention provides a nickel-based alloy composite powder, its preparation method, and its application. The nickel-based alloy composite powder can control the distribution of crack-inducing elements C and Mo in nickel-based alloys. During the material manufacturing process, it forms more M23C6 type carbides in a continuous film-like distribution at grain boundaries, filling the grain boundaries, eliminating forming cracks in nickel-based superalloys, and improving the forming density of the material.

[0030] Specifically, the present invention provides a nickel-based alloy composite powder for eliminating manufacturing cracks in nickel-based alloy additives. It uses nickel-based alloy powder A as raw material and incorporates functional powder containing Mo and C elements into nickel-based alloy powder A (part of the C and Mo elements in the nickel-based alloy are incorporated into the raw material powder in the form of functional powder).

[0031] The nickel-based alloy composite powder provided by this invention can be formed using additive manufacturing technology.

[0032] In this invention, the elemental composition of the nickel-based alloy powder A, by mass percentage, includes: C: 0.05%~0.15%; Cr: 20.00%~24.00%; Co: ≤5.00%; W: 13.00%~15.00%; Mo: 1.00%~3.00%; Al: 0.20%~0.50%; Ti: ≤0.10%; Fe: ≤3.00%; B: ≤0.015%; Si: 0.25%~0.75%; Mn: 0.30%~1.00%; La: 0.005%-0.05%; the balance being Ni.

[0033] In this invention, the Mo and C elements are added as elemental powders or as MoC compound powders.

[0034] The present invention preferably incorporates functional powder in the form of MoC compound powder, and the mass fraction of MoC powder added is 0.5% to 3%.

[0035] In the nickel-based alloy composite powder for eliminating manufacturing cracks in nickel-based alloy additives provided by the present invention, after all Mo and C elements are mixed in, the total mass percentage of C and Mo elements does not exceed the upper limit of the content of each element in nickel-based alloy powder A by 0.15% and 3%, respectively.

[0036] In this invention, the preparation process of nickel-based alloy powder A includes, but is not limited to, vacuum atomization, electrode induction gas atomization, and plasma rotating electrode method, and the morphology of the powder is spherical or near-spherical.

[0037] In this invention, the mixing methods for incorporating Mo and C element powders into the nickel-based alloy powder A include, but are not limited to, ball milling, V-type mixing, three-dimensional mixing, and resonance mixing.

[0038] In this invention, MoC powder is uniformly coated on the surface of nickel-based alloy powder A. The particle size of nickel-based alloy powder A ranges from 15 μm to 150 μm, and the particle size of MoC powder ranges from 0.05 μm to 5 μm.

[0039] This invention forms crack-free alloys through material enhancement manufacturing technology, wherein the material enhancement manufacturing technology is one of laser selective melting, directional energy deposition, or electron beam melting forming processes.

[0040] As a preferred implementation scheme, for laser selective melting, the laser power is 100-300W, the scanning speed is 600-1200mm / s, the scanning spacing is 0.09-0.12μm, and the powder layer thickness is 30-80μm. The laser scanning strategy is linear scanning or checkerboard scanning.

[0041] This invention, by mixing MoC powder into nickel-based alloy powder and leveraging the advantages of laser selective melting (SDM) and other additive manufacturing techniques—small melting area and fast solidification rate—allows for greater precipitation of M23C6 carbides along grain boundaries in the formed nickel-based alloy. This fills solidification cracks, significantly reducing forming cracks and improving forming density. The nickel-based alloy powder proposed in this invention eliminates forming cracks in nickel-based alloys by mixing a portion of the carbon (C) and molybdenum (Mo) elements from the nickel-based alloy into MoC powder. This only alters the form of C and Mo in the powder without introducing any new elements. Furthermore, the total C and Mo content can be controlled within the original range after mixing, which facilitates rapid mass production of this method.

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0043] The endpoints and any values ​​of the ranges disclosed in this specification are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0044] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "specific implementation," or "some specific implementations," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0045] In the embodiments provided in this specification, unless specific techniques or conditions are specified, the techniques or conditions described in the literature in this field, or the product instructions, shall be followed. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased from legitimate channels.

[0046] Example 1:

[0047] (1) In this embodiment, the nickel-based alloy used is GH3230 alloy, and the mass percentage of the alloy composition is: C: 0.06; Cr: 22.3; Co: 2.0; W: 13.5; Mo: 1.8; Al: 0.4; Ti: 0.08; Fe: 1.6; B: 0.005; Si: 0.42; Mn: 0.50; La: 0.009.

[0048] (2) GH3230 powder containing the components described in (1) is prepared by vacuum atomization process. Coarse and ultrafine particles in the powder are removed by sieving and air classification processes to obtain GH3230 powder with a particle size of 15-53μm.

[0049] (3) Powder mixing: 50nm MoC powder was added to GH3230 powder, and the addition ratio of MoC powder was 1%. A three-dimensional mixer was used to fully mix 15-53μm GH3230 powder and MoC powder. The speed of the three-dimensional mixer was 20rpm / min and the mixing time was 6h.

[0050] The morphology of the mixed powder is as follows Figure 1 As shown.

[0051] (4) Add the uniformly mixed powder into the laser selective melting equipment. The forming size of the equipment is 125mm*125mm*125mm. Stainless steel is selected as the forming substrate. The substrate is installed on the forming platform and heated to 200℃. High-purity argon gas with a purity of 99.99wt.% is introduced to protect the equipment. When the oxygen content is less than 10ppm, the laser is turned on for forming. The forming process parameters are: laser power: 180W, scanning speed: 800mm / s, scanning spacing: 0.09mm, scanning layer thickness: 0.03mm, and the scanning strategy is linear scanning.

[0052] (5) The obtained GH3230 alloy sample was subjected to forming crack analysis. The metallographic results are as follows: Figure 2 As shown. From Figure 2 As can be seen, only a small number of pores exist in the morphologically formed sample, and no cracks were observed. The distribution of grain boundary carbides is as follows: Figure 3 As shown, a large amount of M23C6 carbide is distributed in a film-like manner at the grain boundaries, which plays a role in filling cracks and inhibiting crack formation.

[0053] Example 2:

[0054] (1) In this embodiment, the nickel-based alloy used is GH3230 alloy, and the mass percentage of the alloy composition is: C: 0.05; Cr: 22.3; Co: 2.0; W: 13.5; Mo: 1.5; Al: 0.4; Ti: 0.08; Fe: 1.6; B: 0.005; Si: 0.42; Mn: 0.50; La: 0.009.

[0055] (2) GH3230 powder containing the components described in (1) is prepared by vacuum atomization process. Coarse and ultrafine particles in the powder are removed by sieving and air classification processes to obtain GH3230 powder with a particle size of 15-53μm.

[0056] (3) Powder mixing: 50nm MoC powder was added to GH3230 powder, and the addition ratio of MoC powder was 1.5%. A three-dimensional mixer was used to fully mix 15-53μm GH3230 powder and MoC powder, wherein the rotation speed of the three-dimensional mixer was 20rpm / min and the mixing time was 6h.

[0057] (4) Add the uniformly mixed powder into the laser selective melting equipment. The forming size of the equipment is 125mm*125mm*125mm. Stainless steel is selected as the forming substrate. The substrate is installed on the forming platform and heated to 200℃. High-purity argon gas with a purity of 99.99wt.% is introduced to protect the equipment. When the oxygen content is less than 10ppm, the laser is turned on for forming. The forming process parameters are: laser power: 180W, scanning speed: 800mm / s, scanning spacing: 0.09mm, scanning layer thickness: 0.03mm, and the scanning strategy is linear scanning.

[0058] (5) The obtained GH3230 alloy sample was subjected to forming crack analysis. The metallographic results are as follows: Figure 4 The results showed that no cracks were observed in the morphological samples. M23C6 carbides were distributed in a film-like manner at the grain boundaries, which filled the cracks and inhibited their formation.

[0059] Example 3:

[0060] (1) In this embodiment, the nickel-based alloy used is GH3230 alloy, and the mass percentage of the alloy composition is: C: 0.05; Cr: 22.3; Co: 2.0; W: 13.5; Mo: 1.5; Al: 0.4; Ti: 0.08; Fe: 1.6; B: 0.005; Si: 0.42; Mn: 0.50; La: 0.009.

[0061] (2) GH3230 powder containing the components described in (1) is prepared by vacuum atomization process. Coarse and ultrafine particles in the powder are removed by sieving and air classification processes to obtain GH3230 powder with a particle size of 15-53μm.

[0062] (3) Powder mixing: 50nm MoC powder was added to GH3230 powder, and the addition ratio of MoC powder was 1.5%. A three-dimensional mixer was used to fully mix 15-53μm GH3230 powder and MoC powder, wherein the rotation speed of the three-dimensional mixer was 20rpm / min and the mixing time was 6h.

[0063] (4) Add the uniformly mixed powder into the laser selective melting equipment. The forming size of the equipment is 125mm*125mm*125mm. Stainless steel is selected as the forming substrate. The substrate is installed on the forming platform and heated to 200℃. High-purity argon gas with a purity of 99.99wt.% is introduced to protect the equipment. When the oxygen content is less than 10ppm, the laser is turned on for forming. The forming process parameters are: laser power: 220W, scanning speed: 900mm / s, scanning spacing: 0.09mm, scanning layer thickness: 0.03mm, and the scanning strategy is linear scanning.

[0064] (5) The obtained GH3230 alloy sample was subjected to forming crack analysis. The metallographic results are as follows: Figure 5 The results showed that no cracks were observed in the morphological samples. M23C6 carbides were distributed in a film-like manner at the grain boundaries, which filled the cracks and inhibited their formation.

[0065] Comparative Example 1:

[0066] (1) The nickel-based alloy used in this comparative example is GH3230 alloy, and the mass percentage of the alloy composition is as follows: C: 0.06; Cr: 22.3; Co: 2.0; W: 13.5; Mo: 1.8; Al: 0.4; Ti: 0.08; Fe: 1.6; B: 0.005; Si: 0.42; Mn: 0.50; La: 0.009.

[0067] (2) GH3230 powder containing the components described in (1) is prepared by vacuum atomization process. Coarse and ultrafine particles in the powder are removed by sieving and air classification processes to obtain GH3230 powder with a particle size of 15-53μm.

[0068] (3) No MoC powder is added to the powder.

[0069] (4) The obtained GH3230 powder is added to the laser selective melting equipment. The forming size of the equipment is 125mm*125mm*125mm. Stainless steel is selected as the forming substrate. The substrate is installed on the forming platform and heated to 200℃. High-purity argon gas with a purity of 99.99wt.% is introduced to protect the equipment. When the oxygen content is less than 10ppm, the laser is turned on for forming. The forming process parameters are: laser power: 180W, scanning speed: 800mm / s, scanning spacing: 0.09mm, scanning layer thickness: 0.03mm, and the scanning strategy is linear scanning.

[0070] (5) The obtained GH3230 alloy sample was subjected to forming crack analysis. The metallographic results are as follows: Figure 6 As shown, from Figure 6 As can be seen, cracks were observed in the morphologically formed sample. The distribution of grain boundary carbides is as follows: Figure 7 As shown, it can be seen that only a small amount of M23C6 carbide is distributed in a dotted manner at the grain boundaries, which cannot fill and suppress cracks.

[0071] Comparative Example 2:

[0072] (1) The nickel-based alloy used in this comparative example is GH3230 alloy, and the mass percentage of the alloy composition is as follows: C: 0.11; Cr: 22.3; Co: 2.0; W: 13.5; Mo: 2.5; Al: 0.4; Ti: 0.08; Fe: 1.6; B: 0.005; Si: 0.42; Mn: 0.50; La: 0.009.

[0073] (2) GH3230 powder containing the components described in (1) is prepared by vacuum atomization process. Coarse and ultrafine particles in the powder are removed by sieving and air classification processes to obtain GH3230 powder with a particle size of 15-53μm.

[0074] (3) No MoC powder is added to the powder.

[0075] (4) The obtained GH3230 powder is added to the laser selective melting equipment. The forming size of the equipment is 125mm*125mm*125mm. Stainless steel is selected as the forming substrate. The substrate is installed on the forming platform and heated to 200℃. High-purity argon gas with a purity of 99.99wt.% is introduced to protect the equipment. When the oxygen content is less than 10ppm, the laser is turned on for forming. The forming process parameters are: laser power: 220W, scanning speed: 900mm / s, scanning spacing: 0.09mm, scanning layer thickness: 0.03mm, and the scanning strategy is linear scanning.

[0076] (5) The obtained GH3230 alloy sample was subjected to forming crack analysis. The metallographic results are as follows: Figure 8 As shown, from Figure 8 As can be seen, cracks were observed in the morphological sample.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A nickel-based alloy, characterized in that, It is obtained by additive manufacturing from the following nickel-based alloy composite powder: The nickel-based alloy composite powder is composed of a base powder and a functional powder; the base powder is GH3230 nickel-based alloy powder with a particle size of 15-150 μm; the functional powder is MoC compound powder with a particle size of 0.05-5 μm; the amount of the functional powder added to the nickel-based alloy composite powder is 0.5%~3%. During the material manufacturing process, the nickel-based alloy composite powder forms M23C6 type carbides, which are continuously distributed in a film at the grain boundaries of the nickel-based alloy, thus filling the grain boundaries. The additive manufacturing method is selective laser melting; wherein the laser power is 180-220W, the scanning speed is 800-900mm / s, the scanning interval is 0.09mm, and the powder layer thickness is 30μm. The nickel-based alloy GH3230 powder comprises the following components by mass percentage: C: 0.05%~0.15%; Cr: 20.00%~24.00%; Co: ≤5.00%; W: 13.00%~15.00%; Mo: 1.00%~3.00%; Al: 0.20%~0.50%; Ti: ≤0.10%; Fe: ≤3.00%; B: ≤0.015%; Si: 0.25%~0.75%; Mn: 0.30%~1.00%; La: 0.005%-0.05%; with the balance being Ni. In the nickel-based alloy composite powder, the total mass percentage of C does not exceed 0.15%; and the total mass percentage of Mo does not exceed 3.00%. MoC powder is uniformly coated onto the surface of nickel-based alloy GH3230 powder through mixing.

2. The nickel-based alloy according to claim 1, characterized in that, The particle size of MoC compound powder is 50 nm; the particle size of nickel-based alloy GH3230 powder is 15-53 μm.

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