Dynamic self-enhancement dislocation configuration regulation and control method for refractory alloy in additive manufacturing and application of dynamic self-enhancement dislocation configuration regulation and control method

Abstract

The invention discloses a dynamic self-enhanced dislocation configuration regulation and control method for additive manufacturing refractory alloy and application, Ta-10W alloy powder is subjected to laser printing forming by adopting a selective laser melting method, and the additive manufacturing refractory alloy with a coagulated cell structure and high dislocation density is obtained; and under the vacuum degree condition, short-time medium-temperature stress relief annealing is conducted on the additive manufacturing refractory alloy at the melting point of 0.35-0.55 Tm, and the refractory alloy with the dynamic self-enhancement dislocation configuration coupled with solidification cells and immovable dislocation is obtained. According to the method, complex and random dislocation configuration in the additive manufacturing refractory alloy material is rearranged through heat treatment, the dislocation configuration is regulated and controlled to be distributed around solidification cell walls to form immovable dislocations, the room-temperature strength and the ultra-high-temperature strength of the refractory alloy material are remarkably improved, dynamic self-enhancement of the dislocation cell structure is achieved, the room-temperature strength and the ultra-high-temperature strength of the refractory alloy material are improved, and the service life of the refractory alloy material is prolonged. And ultrahigh-temperature strain hardening is realized. The method has a wide application prospect in extreme service environments such as metallurgy, aerospace and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing refractory alloy preparation, and specifically relates to a method for controlling the dynamic self-enhanced dislocation configuration of additively manufactured refractory alloys and its application. Background Art

[0002] Ultra-high temperature refractory alloys are a class of special metal materials composed of metals with melting points exceeding 2000°C, such as tantalum, tungsten, molybdenum, niobium, and other elements, that have excellent performance in extremely high temperature environments. They are designed to maintain stability and strength under conditions that exceed the heat resistance limits of conventional alloys and steels. Ultra-high temperature refractory alloys have important applications in aerospace, energy, chemical industry and other fields. A typical application scenario for ultra-high temperature refractory alloys is to manufacture core components of hypersonic aircraft, which requires the material to remain stable for a long time at 1800°C or even 3000°C. Such a high service environment temperature is far beyond the upper limit that general structural materials, including existing high-temperature alloys, can withstand. At the same time, for the refractory alloy system with the highest melting point, the service temperature is also above 0.6 times its melting point, which places extremely stringent requirements on the material's ultra-high temperature and high load-bearing capabilities. Therefore, there is an urgent need to find materials that can withstand ultra-high temperatures (>0.6T m ,T m It is an ultra-high temperature and high load-bearing refractory alloy with high tensile strength, high temperature strain hardening ability, and large room temperature tensile elongation.

[0003] For metal materials, dislocations are the main carrier for regulating the balance between strength and plasticity, and different dislocation configurations will have a huge impact on the performance of the material. This is especially true for body-centered cubic refractory alloys. Due to the intrinsic high dislocation energy of body-centered cubic metals, the nucleation and movement of dislocations are relatively difficult. At the same time, body-centered cubic metals have a large number of slip systems. When there is a temperature field or force field that can activate dislocations, the dislocation reaction will be particularly intense. The dislocation activation of the two slip systems will react with each other to form immovable dislocations, and this immovable dislocation will further evolve into a multi-angle dislocation network under high temperature conditions. Both immovable dislocations and multi-angle dislocation networks are configurations with the lowest dislocation energy, and can exist relatively stably at room temperature and high temperature. They promote the improvement of mechanical properties by hindering the movement of movable dislocations. Therefore, dislocation regulation engineering is of great significance to ultra-high temperature refractory alloys. Many researchers or technicians use plastic processing methods such as equal channel extrusion and high energy forging to introduce high-density dislocations in body-centered cubic refractory alloys such as pure W and TiZrHfTa to improve strength. However, the dislocation configurations obtained by these methods are mainly high-density entangled dislocations, which are often accompanied by the sacrifice of material plasticity. There are also problems such as limited sample size and processing conditions. Therefore, it is difficult to achieve a synergistic improvement in high-temperature ultra-high strength and room-temperature plasticity. At present, dislocation control and performance improvement of ultra-high temperature refractory alloys are still a major problem. Summary of the invention

[0004] In order to solve the above-mentioned defects existing in the prior art, the purpose of the present invention is to provide a method for controlling the dynamic self-reinforcement of dislocation configuration of refractory alloys in additive manufacturing, by introducing a solidification cell structure into the refractory alloy during the solidification process, and simultaneously introducing high-density dislocations in combination with high thermal stress cycles during the molding process; under the action of annealing, the dislocations are rearranged to form immovable dislocations distributed around the solidification cell wall, constructing the initial dislocation cell configuration, realizing the dynamic self-reinforcement of the dislocation cell structure, improving the room temperature and ultra-high temperature strength of the refractory alloy, and realizing ultra-high temperature strain hardening.

[0005] The present invention is achieved through the following technical solutions.

[0006] One aspect of the present invention provides a method for controlling the dynamic self-enhanced dislocation configuration of a refractory alloy in additive manufacturing, comprising:

[0007] The Ta-10W alloy powder was laser printed using the selective laser melting technology to obtain an additively manufactured refractory alloy with a solidification cell structure and a high dislocation density; there is no coupling relationship between the solidification cell and the high-density dislocations;

[0008] Under vacuum conditions, additive manufacturing of refractory alloys in the range of 0.35 to 0.55 T m A short-time medium-temperature stress relief annealing is carried out at the melting point of the refractory alloy. During the annealing process, dislocation reactions occur between the dislocations of the additively manufactured refractory alloy to form immovable dislocation configurations that are uniformly distributed around the solidification cell wall, thereby obtaining a refractory alloy with a dynamic self-reinforced dislocation configuration coupled with the solidification cell and the immovable dislocations.

[0009] Preferably, Ta-10W alloy powder adopts raw materials with the following mass ratio:

[0010] Carbon: 0.01-0.05%, Nitrogen: 0.02-0.08%, Oxygen: 0.16-0.2%, Tungsten: 9.5-10.5%, and the balance is tantalum.

[0011] As a preference, the laser printing scanning speed is 400-700 mm / s, and the energy density is 220-260 J / mm 3 .

[0012] Preferably, the refractory alloy with high dislocation density obtained by laser printing is heated to 0.35-0.55T at a heating rate of 8-12°C / min to the melting point of Ta-10W alloy 3035°C. m Stress relief annealing is performed.

[0013] Preferably, the annealing temperature is 1200-1500° C., and the annealing time is 1-2 hours.

[0014] Preferably, the temperature fluctuation during annealing is less than 20°C.

[0015] Preferably, the vacuum degree is less than 5×10 -3 The as-printed Ta-10W alloy was subjected to stress relief annealing in a vacuum furnace of 1.5 Pa.

[0016] Another aspect of the present invention provides a refractory alloy with a dynamic self-enhanced dislocation configuration obtained by the above method.

[0017] The present invention adopts the above technical solution, which has the following beneficial effects:

[0018] 1. The present invention adopts metal additive manufacturing technology to prepare ultra-high temperature refractory alloys. Compared with traditional deformation processes such as rolling, the rapid solidification process introduces a solidification cell structure into the refractory alloy, combined with the high thermal stress cycle in the molding process, and simultaneously introduces high-density dislocations.

[0019] 2. The present invention rationally controls the heat treatment holding temperature and holding time, controls the distribution of immovable dislocations at the solidification cell wall, and can realize dynamic self-reinforcement of the dislocation cell structure during plastic deformation, thereby achieving a synergistic improvement in the strength and strain hardening ability of the refractory alloy.

[0020] 3. The present invention reshapes the dislocation configuration through a heat treatment process, and rearranges the complex and random dislocation configuration in the additive manufacturing refractory alloy material. These immovable dislocations distributed around the solidified cell wall can hinder the slip of movable dislocations during the plastic deformation stage, and promote dislocation reactions between movable dislocations. A large number of immovable dislocations are generated at the solidified cell wall of the additive manufacturing ultra-high temperature refractory alloy, which become effective pinning points and reaction sites for movable dislocations, thereby realizing dynamic self-reinforcement of the dislocation cell structure. Compared with the ultra-high temperature refractory alloy prepared by the current commercial traditional process, the room temperature strength is increased by about 40%, and the ultra-high temperature strength (>0.6T m ) significantly improved, at 0.66T m The strength is increased by about 20% and it still has the ability to strain harden.

[0021] 4. The present invention adopts the design idea of ​​introducing high density dislocations by selective laser melting with high temperature gradient and high cyclic stress + gradually controlling the dislocation structure, providing a simple method for preparing high strength and high strain hardening body-centered cubic alloys, which can be extended to other body-centered cubic alloy materials. The refractory alloy with dynamic self-enhanced dislocation configuration obtained by the method can be widely used in metallurgy and aerospace at room temperature or ultra-high temperature environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of the present application, and do not constitute an improper limitation of the present invention. In the drawings:

[0023] Figure 1 The relationship between the solidification cell and dislocation imaged under electron channel contrast before annealing;

[0024] Figure 2 Schematic diagram of the relationship between the solidification cell and different dislocation configurations before annealing;

[0025] Figure 3 The relationship between the solidification cell and dislocation imaged under electron channel contrast after annealing;

[0026] Figure 4 Schematic diagram of the relationship between the solidification cell and different dislocation configurations after annealing;

[0027] Figure 5 is the annealing flow chart;

[0028] Figure 6 This is a comparison chart of the room temperature tensile properties of Example 1 and the conventional process Ta-10W alloy;

[0029] Figure 7 The 2000℃ (~0.66T) temperature of the Ta-10W alloy in Example 1 and the conventional process m )Comparison chart of ultra-high temperature tensile properties. DETAILED DESCRIPTION

[0030] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The exemplary embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0031] An embodiment of the present invention provides a method for controlling the dynamic self-enhanced dislocation configuration of a refractory alloy in additive manufacturing, and the steps are as follows:

[0032] Step 1: Select Ta-10W alloy spherical powder with a particle size of 15-63 μm, use the selective laser melting method, and use a laser scanning speed of 400-700 mm / s and a laser energy density of 220-260 J / mm 3 The Ta-10W alloy powder is printed and formed, a solidification cell structure is introduced into the refractory alloy, and high-density dislocations are simultaneously introduced in combination with high thermal stress cycles during the molding process; an additively manufactured refractory alloy with a solidification cell structure and high dislocation density is obtained.

[0033] The Ta-10W alloy powder comprises the following alloy elements in a mass ratio: carbon element: 0.01-0.05%, nitrogen element: 0.02-0.08%, oxygen element: 0.16-0.2%, tungsten element: 9.5-10.5%, and the balance is tantalum element.

[0034] Commercial alloy spherical powder with corresponding refractory components is used. Selective laser melting is used for printing, strip printing is used as the printing strategy, and high G / R printing parameters are selected to obtain the solidification cell structure (G is the temperature gradient during the solidification process, and R is the cooling rate during solidification). Finally, a refractory alloy with good density, basically no fusion defects and high prefabricated dislocation density is obtained.

[0035] Step 2: The high dislocation density additive manufacturing refractory alloy obtained in step 1 is placed in a vacuum of less than 5×10 -3 The printed Ta-10W alloy was subjected to a short-time stress relief annealing heat treatment in a vacuum furnace of 1.5 Pa, using a temperature of 0.35 to 0.55 T at the melting point of the Ta-10W alloy (the melting point of the Ta-10W alloy is 3035 ° C). m The temperature range (1060℃~1670℃) is kept within 1~2 hours of stress relief annealing to achieve the control of immobile dislocation configuration. The heating rate in the annealing heat treatment experiment is kept within the range of 8~12℃ / min, and the temperature fluctuation is less than 20℃ during the insulation.

[0036] Among them, there are two substructures in additively manufactured refractory alloys: solidification cells and high-density entangled dislocations. Solidification cells are substructures produced during the solidification process with high temperature gradient and high cooling rate, and high-density entangled dislocations are produced by large temperature gradients and high stress cycles when preparing samples by selective laser melting process. Relying on solidification cells as dislocation pinning sites, combined with the ability of a short-term medium-temperature annealing to regulate body-centered cubic dislocations, dislocations react at the boundaries of solidification cells to generate immobile dislocation configurations. Constructing a stable initial dislocation cell morphology and laying the foundation for the dynamic self-enhancement of the dislocation cell structure promoted by dislocation reactions during deformation, the room temperature and ultra-high temperature strength of refractory alloys are improved and ultra-high temperature strain hardening is achieved.

[0037] In step 2, the stress relief annealing parameters are selected to be 0.35~0.55T m. First, for the melting point temperature of refractory alloys that is 0.35 to 0.55 times the annealing temperature, if the temperature is too low, on the one hand, it is not enough to eliminate the high internal stress in the additively manufactured refractory alloys, and the sample will crack due to excessive internal stress during service; on the other hand, it will lead to insufficient thermal activation energy, so that dislocations cannot spontaneously form immovable dislocations under the temperature field, and thus cannot hinder movable dislocations during plastic deformation. If the temperature is too high. On the one hand, it will cause dynamic recrystallization of the refractory alloy and the grains will grow; on the other hand, it will cause a large number of dislocations to be annihilated and the dislocation density will be greatly reduced. Both will lead to a decrease in the mechanical properties of ultra-high temperature refractory alloys. Selection of annealing time: If the annealing time is insufficient, more internal stress will remain inside the material. If the annealing time is too long, it will also lead to recrystallization and dislocation annihilation. Through stress relief annealing, on the one hand, dislocations can spontaneously form low-energy immovable dislocation configurations; on the other hand, compared with the uniform matrix, the high cooling rate and high temperature gradient in the solidification process of additive manufacturing will form a substructure of solidification cells inside the grains. This substructure becomes the main site for the distribution of immovable dislocations after annealing. The results show that after stress relief annealing, the immovable dislocations in the printed annealed ultra-high temperature refractory alloy are relatively uniformly dispersed in the solidification cell wall. This dislocation configuration can effectively hinder dislocation movement during plastic deformation, effectively improving the yield strength and strain hardening ability of ultra-high temperature refractory alloys.

[0038] Furthermore, the annealing temperature is 1200-1500° C. and the holding time is 1-2 hours, which is a preferred embodiment of the present invention.

[0039] By rearranging dislocations at high temperatures, the complex and random dislocation configuration is regulated into immovable dislocations distributed around the solidification cell wall, constructing the initial dislocation cell morphology and laying the foundation for dynamically strengthening the dislocation cells through dislocation reactions during the plastic deformation process, thus obtaining an additively manufactured refractory alloy in which the solidification cell and immovable dislocations are coupled.

[0040] Due to the intrinsic high dislocation energy of body-centered cubic refractory metals, it is difficult for dislocations to be generated and activated. However, due to the characteristics of the numerous dislocation slip systems in body-centered cubic metals, when there is a temperature field or force field that can activate dislocations, the dislocation reaction will be particularly intense. The dislocation activation of the two slip systems will react with each other to form an immovable dislocation. The 1 / 2 of the two different Burgers vectors <111> The Burgers vector generated by the interaction between dislocations is <100> Immobile dislocations (e.g. ). <100> The immovable dislocations of this type will become obstacles to dislocation slip in subsequent deformation, prompting more dislocations to undergo dislocation reactions during plastic deformation to form new immovable dislocation pinning points, thereby improving the strength and strain hardening ability of refractory alloys.

[0041] Based on the characteristics of body-centered cubic metal dislocations, the present invention has the following idea for regulating dislocations in refractory alloys: first, commercial refractory alloy powders with good sphericity are used as raw materials, and the refractory alloy powders are subjected to selective laser melting processing. The printed refractory alloy with solidification cells and high-density entangled dislocations is obtained by selective laser melting, an additive manufacturing method. Then, the printed refractory alloy is obtained by heating the refractory alloy powders at 0.35-0.55T. m (T m The dislocation configuration is regulated by a short-time (1 to 2 hours) stress relief annealing in the temperature range of (the melting point of the material), the high internal stress in the refractory alloy for additive manufacturing is reduced, and at the same time, under high-temperature thermal activation, the dislocation tends to transform into a low-energy stable immovable dislocation configuration, and the complex random dislocation configuration is regulated into an immovable dislocation configuration with the solidification cell structure as the pinning site, constructing a stable initial dislocation cell morphology and continuously causing dislocation reactions during the plastic deformation process to achieve self-reinforcement of the dislocation cell structure. In additive manufacturing, the solidification cell wall formed by high cooling rate and high temperature gradient becomes the best site for the nucleation of immovable dislocations. Therefore, the result shows that the refractory solidification cells and immovable dislocations in additive manufacturing after annealing are highly coupled. During the plastic deformation process, the coupling effect of the two will become an obstacle to the movement of movable dislocations, thereby improving the yield strength of the refractory alloy; and construct a cellular coupling structure in which immovable dislocations are dispersed in the solidification cell wall. The existence of this cellular structure enables the ultra-high temperature refractory alloy manufactured in additive manufacturing to exhibit ultra-high strength and ultra-high strain hardening ability during room temperature and ultra-high temperature plastic deformation. Under the premise of eliminating the internal stress of the additively manufactured ultra-high temperature refractory alloy, this process rearranges the complex and random dislocation configuration in the additively manufactured refractory alloy material, and regulates it into a cellular immovable dislocation configuration with the solidification cell wall as the pinning site, constructing a cellular structure in which the immovable dislocation and the solidification cell are coupled. This cellular structure can continuously react with the movable dislocation during the room temperature and ultra-high temperature plastic deformation process to form immovable dislocations to achieve self-reinforcement, so that the additively manufactured ultra-high temperature refractory alloy can be made at room temperature and ultra-high temperature (>0.6T m ) has excellent yield strength and strain hardening ability. On the other hand, the solidified cell wall with a large number of immovable dislocations also serves as the site of dislocation reaction, so that dislocation reaction continues to occur in the solidified cell wall, and the dislocations in the solidified cell wall gradually self-strengthen to form dislocation cells, which provides excellent strain hardening ability. In addition, the dislocation configuration formed in this way is very strong in ultra-high temperature environment (>0.6T m ) will not be completely decomposed, so it can be used at ultra-high temperatures (>0.6T m ) provides higher strength and strain hardening ability.

[0042] The performance of this additively manufactured refractory alloy is shown to be about 40% higher in room temperature strength and 40% higher in ultra-high temperature strength (>0.6T) than that of conventional commercial alloys, while maintaining the same room temperature plasticity. m) significantly improved, at 0.66T m The strength is increased by about 20% and ultra-high temperature strain hardening can be achieved.

[0043] This method introduces a solidification cell structure into the refractory alloy through the rapid solidification process unique to the additive manufacturing process, and simultaneously introduces high-density dislocations in combination with the high thermal stress cycle during the molding process; combined with a short-term medium-temperature annealing step, the dislocations in the body-centered cubic alloy are regulated, and under the action of annealing, the dislocations are rearranged to form immovable dislocations distributed around the solidification cell wall, constructing the initial dislocation cell configuration. This dislocation cell configuration can continuously react with movable dislocations to form immovable dislocations during the plastic deformation stage, thereby realizing dynamic self-reinforcement of the dislocation cell structure. This structure improves the room temperature and ultra-high temperature strength of the refractory alloy and realizes ultra-high temperature strain hardening.

[0044] Different embodiments are given below to further illustrate the method of the present invention.

[0045] Example 1

[0046] Step 1: Selective laser melting technology is used to print Ta-10W alloy powder (chemical composition: carbon: 0.03%, nitrogen: 0.08%, oxygen: 0.16%, tungsten: 9.5%, tantalum: balance). The laser scanning speed used for printing is 540mm / s, and the energy density is 246.91J / mm 3 .

[0047] The positional relationship between the solidification cells and dislocations in the printed sample was observed by electron channel contrast imaging, such as Figure 1 As shown in the figure, there is no coupling relationship between the two, and there are a large number of randomly arranged tangled dislocations inside the honeycomb-shaped solidification cells. The schematic diagram of the relationship between the solidification cells and dislocations in the sample after printing is shown in the figure. Figure 2 shown.

[0048] Step 2: When the vacuum degree is less than 5×10 -3 Pa in a vacuum furnace to print Ta-10W alloy at 0.35~0.55T m The melting point is subjected to stress relief annealing treatment, the annealing temperature is 1500°C, the annealing time is 1 hour, the heating rate is maintained within the range of 10°C / min, and the temperature fluctuation during annealing is less than 20°C.

[0049] The positional relationship between the solidification cells and dislocations in the annealed sample was observed by electron channel contrast imaging, e.g. Figure 3As shown in Table 1, after annealing, a large number of dislocations form low-energy immovable dislocation configurations (the Burgers vector of immovable dislocations is determined according to the extinction rule, as shown in Table 1), and the immovable dislocations are distributed at the solidification cell wall position, and there is a coupling relationship between the immovable dislocations and the solidification cells. The schematic diagram of the relationship between the solidification cells and dislocations in the sample after annealing is shown in Figure 4 The flow chart of dislocation configuration control of printed Ta-10W alloy under stress relief annealing process is shown in Figure 5 shown.

[0050] Example 2

[0051] Step 1: Use selective laser melting technology to print Ta-10W alloy powder (chemical composition: carbon: 0.01%, nitrogen: 0.02%, oxygen: 0.17%, tungsten: 10%, tantalum: balance). The laser scanning speed used for printing is 600mm / s and the energy density is 220J / mm 3 .

[0052] Step 2: When the vacuum degree is less than 5×10 -3 Pa in a vacuum furnace to print Ta-10W alloy at 0.35~0.55T m The melting point is subjected to stress relief annealing treatment, the annealing temperature is 1200°C, the annealing time is 1.5 hours, the heating rate is maintained within the range of 9°C / min, and the temperature fluctuation during annealing is less than 20°C.

[0053] Example 3

[0054] Step 1: Use selective laser melting technology to print Ta-10W alloy powder (chemical composition: carbon: 0.05%, nitrogen: 0.06%, oxygen: 0.2%, tungsten: 10.5%, tantalum: balance). The laser scanning speed used for printing is 400mm / s, and the energy density is 230J / mm 3 .

[0055] Step 2: When the vacuum degree is less than 5×10 -3 Pa in a vacuum furnace to print Ta-10W alloy at 0.35~0.55T m The melting point is subjected to stress relief annealing treatment, the annealing temperature is 1670°C, the annealing time is 1 hour, the heating rate is maintained within the range of 12°C / min, and the temperature fluctuation during annealing is less than 20°C.

[0056] Example 4

[0057] Step 1: Use selective laser melting technology to print Ta-10W alloy powder (chemical composition: carbon: 0.02%, nitrogen: 0.04%, oxygen: 0.18%, tungsten: 9.5%, tantalum: balance). The laser scanning speed used for printing is 700mm / s, and the energy density is 240J / mm 3 .

[0058] Step 2: When the vacuum degree is less than 5×10 -3 Pa in a vacuum furnace to print Ta-10W alloy at 0.35~0.55T m The melting point is subjected to stress relief annealing treatment, the annealing temperature is 1060°C, the annealing time is 2 hours, the heating rate is maintained within the range of 8°C / min, and the temperature fluctuation during annealing is less than 20°C.

[0059] The method of the present invention is verified by improving mechanical properties.

[0060] Quasi-static tensile tests (test rate 10 -3 s -1 ) to verify the effect of immobile dislocations on the mechanical properties of Ta-10W alloy. Figure 6 As shown, the room temperature yield strength of the printed annealed Ta-10W alloy prepared in the embodiment of the present invention can reach 693 MPa, which is about 200 MPa higher than the yield strength of the commercial Ta-10W alloy produced by the conventional process, about 40%, and the strain hardening ability is also better than the Ta-10W alloy produced by the conventional process; Figure 7 As shown, the printed annealed Ta-10W alloy prepared in the embodiment of the present invention is heated to 2000°C (0.66T m , T m The ultra-high temperature yield strength (temperature at which the alloy melts) exceeds 120 MPa, which is about 20% higher than the yield strength of commercial Ta-10W alloy produced using traditional processes. At the same time, it has strain hardening capability at ultra-high temperatures.

[0061] Table 1 Dislocation extinction rules for body-centered cubic crystals

[0062]

[0063] Visible dislocation means that the dislocation of the Burgers vector in the direction of the crystal plane is visible; invisible dislocation means that the dislocation of the Burgers vector in the direction of the crystal plane is invisible.

[0064] The visible and invisible patterns of dislocations in different crystal plane directions can be used to determine the Burgers vector of dislocations.

[0065] From the above embodiments and the attached Figure 1-7It can be seen that the present invention makes full use of the dislocation characteristics of body-centered cubic refractory alloys and the regulation of alloy substructure by selective laser melting technology, adopts a medium-temperature short-time stress relief annealing strategy, and designs and constructs a dislocation configuration in which solidification cells are coupled with immovable dislocations. This dislocation configuration can achieve self-reinforcement during room temperature and ultra-high temperature plastic deformation, and finally achieves the purpose of synergistically improving the room temperature and ultra-high temperature strength of refractory alloys. The method of the present invention is simple, and has a significant effect on improving the mechanical properties at room temperature and ultra-high temperature, and has broad application prospects in extreme service environments such as metallurgy and aerospace.

[0066] The present invention is not limited to the above-mentioned embodiments. On the basis of the technical solution disclosed in the present invention, technicians in this field can make some substitutions and deformations to some technical features therein according to the disclosed technical content without creative labor, and these substitutions and deformations are all within the protection scope of the present invention.

Claims

1. A method for controlling the dynamic self-enhanced dislocation configuration of refractory alloys in additive manufacturing, characterized in that: include: The Ta-10W alloy powder was laser printed by selective laser melting to obtain an additively manufactured refractory alloy with a solidification cell structure and high dislocation density. Under vacuum conditions, additive manufacturing of refractory alloys in the range of 0.35 to 0.55 T m A short-time medium-temperature stress relief annealing is carried out at the melting point of , and after cooling, a refractory alloy with a dynamic self-reinforced dislocation configuration coupled with solidification cells and immobile dislocations is obtained.

2. The method for controlling the dynamic self-enhanced dislocation configuration of refractory alloys in additive manufacturing according to claim 1, characterized in that: Ta-10W alloy powder uses the following raw materials in mass ratio: Carbon: 0.01-0.05%, Nitrogen: 0.02-0.08%, Oxygen: 0.16-0.2%, Tungsten: 9.5-10.5%, and the balance is tantalum.

3. The method for controlling the dynamic self-enhanced dislocation configuration of refractory alloys in additive manufacturing according to claim 1, characterized in that: Laser printing scanning speed is 400-700mm / s, energy density is 220-260J / mm 3 .

4. The method for controlling the dynamic self-enhanced dislocation configuration of refractory alloys in additive manufacturing according to claim 1, characterized in that: The additively manufactured refractory alloy with high dislocation density obtained by laser printing is subjected to stress relief annealing at a heating rate of 8 to 12°C / min and a temperature of 35 to 55% of the melting point of Ta-10W alloy 3035°C.

5. The method for controlling the dynamic self-enhanced dislocation configuration of refractory alloys in additive manufacturing according to claim 4, characterized in that: The short-term medium-temperature stress relief annealing temperature is 1200-1500°C, and the annealing time is 1-2 hours.

6. The method for controlling the dynamic self-enhanced dislocation configuration of refractory alloys in additive manufacturing according to claim 4, characterized in that: The temperature fluctuation during annealing and insulation is less than 20℃.

7. The method for controlling the dynamic self-enhanced dislocation configuration of refractory alloys in additive manufacturing according to claim 1, characterized in that: At a vacuum degree lower than 5×10 -3 The as-printed Ta-10W alloy was subjected to stress relief annealing in a vacuum furnace of 1.5 Pa.

8. A refractory alloy having a dynamic self-enhanced dislocation configuration obtained by the control method according to any one of claims 1 to 7.

9. A refractory alloy with a dynamically self-enhanced dislocation configuration as claimed in claim 8 for use in metallurgy and aerospace at room temperature or ultra-high temperature environments.

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