High-flux alloy component screening method based on friction stir gradient alloying

Abstract

The invention discloses a high-flux alloy component screening method based on friction stir gradient alloying. The high-flux alloy component screening method comprises the steps that an isosceles triangle groove is formed in the upper surface of a basic alloy plate; an isosceles triangle metal plate made of metal to be added is added into the isosceles triangle groove; a stirring needle is inserted into the basic alloy plate, stirring friction gradient alloying treatment is conducted on the area where the isosceles triangle groove is located, and an alloy plate with alloy components distributed in a gradient mode from the bottom edge of the isosceles triangle groove to the vertex angle of the isosceles triangle groove is obtained; sampling is conducted on the surface of the obtained alloy plate in the length direction at preset intervals, and a plurality of alloy samples are obtained; component and performance detection is conducted on each obtained alloy sample, high-throughput alloy component screening is achieved according to performance detection results, and performance detection comprises tensile strength and ductility. The method belongs to a short-process preparation technology, and the high-flux component screening of the high-entropy alloy can be realized by combining a high-entropy alloy design criterion and stirring friction gradient alloying.

Description

Technical Field

[0001] The invention belongs to the technical field of new material preparation and processing, and specifically relates to a high-throughput alloy component screening method based on friction stir gradient alloying. Background Art

[0002] The concept of alloying has been used to improve metal properties. The existing alloy composition design mainly adopts the traditional trial and error method, which has the following defects: it needs to go through a long process of "casting-homogenization-hot rolling-cold rolling-annealing". With the increase of the number of main element metals, it takes decades to complete the composition design of a high entropy alloy series. The alloy design and screening cycle is long and the design success rate is low. It is easy to cause uneven alloy structure, voids, cracks and other defects during the preparation process. Subsequent deformation and heat treatment are required to eliminate the original casting defects and achieve homogenization of the structure, resulting in a long preparation cycle and low efficiency of the alloy. Plastic deformation and heat treatment processes are separated, and it is impossible to integrate the thermomechanical coupling to regulate the microstructure of the alloy and achieve microstructure refinement, homogenization and densification. With the continuous advancement of science, the demand for high entropy alloys is also increasing. Therefore, how to improve the efficiency of alloy composition design and screening has become the key to the research and development of new alloy materials. Summary of the invention

[0003] In view of the defects and shortcomings of the prior art, the purpose of the present invention is to provide a high-throughput alloy composition screening method based on stir friction gradient alloying to solve the technical problems of long alloy design and screening cycle and low preparation efficiency existing in the prior art.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A high-throughput alloy composition screening method based on friction stir gradient alloying comprises the following steps:

[0006] Step 1: An isosceles triangle groove is formed on the upper surface of the base alloy plate, and the base of the isosceles triangle groove and the vertex of the isosceles triangle groove are located in the same horizontal plane;

[0007] Step 2: adding an isosceles triangle metal plate made of the metal to be added into the isosceles triangle groove, wherein the outer contour of the isosceles triangle metal plate matches the inner contour of the isosceles triangle groove, and the metal to be added can be alloyed with the basic alloy plate;

[0008] Step 3, inserting a stirring needle into the base alloy plate, and performing a stirring friction gradient alloying treatment on the area where the isosceles triangle groove is located, to obtain an alloy plate in which the alloy composition is gradiently distributed along the bottom edge of the isosceles triangle groove to the top angle of the isosceles triangle groove;

[0009] The friction stir gradient totalization includes at least one friction stir treatment; the insertion depth of the stirring needle is the vertical distance from the bottom of the isosceles triangle groove to the upper surface of the base alloy plate;

[0010] Step 4: sampling the surface of the obtained alloy plate at preset intervals along the length direction to obtain multiple alloy samples; performing component and performance tests on each of the obtained alloy samples, and realizing high-throughput alloy component screening according to the performance test results;

[0011] The performance tests include tensile strength and elongation.

[0012] The present invention also has the following technical features:

[0013] Specifically, the metal element to be added meets the following conditions:

[0014] and

[0015] Where:

[0016] δ is the atomic radius difference of the target alloy;

[0017] r i is the atomic radius of the i-th element in the target alloy, in nm;

[0018] is the average atomic radius of the target alloy, in nm;

[0019] N is the total number of elements in the target alloy;

[0020] C i is the atomic percentage of the i-th element in the target alloy;

[0021] Ω is the thermodynamic parameter of the target alloy;

[0022] T m is the melting point of the target alloy, in K;

[0023] ΔS mix is the mixing entropy of the target alloy, in J·(K·mol) -1 ;

[0024] ΔH mix is the mixing enthalpy of the target alloy, in J·mol -1 .

[0025] Furthermore, the thickness of the basic alloy plate is 4 to 10 mm.

[0026] Furthermore, in the alloy plate described in step 3, the amount of the metal to be added is 1 to 30 at. % in atomic percentage.

[0027] Furthermore, the metal to be added includes Cu, Cr, Ni, Ti and Al.

[0028] Furthermore, the stirring head is a W-Re alloy stirring head, which includes a shoulder and a stirring needle. The shoulder has a diameter of 10 to 16 mm, and the stirring needle is conical; the root diameter of the stirring needle is 4 to 8 mm, the top diameter is 3 to 6 mm, and the needle length is 1.5 to 3 mm.

[0029] Furthermore, in the friction stir gradient alloying process, the rotation speed of the stirring head is 200 to 1000 r / min, and the forward speed is 10 to 60 mm / min.

[0030] Furthermore, the preset interval in step 4 is 8 to 10 mm.

[0031] Furthermore, the basic alloy plate includes Fe 40 Mn 20 Co 20 Cr 15 Si5 alloy sheet and CoCrFeMnNi alloy sheet.

[0032] Compared with the prior art, the present invention has the following technical effects:

[0033] The method of the invention belongs to a short-process preparation technology, combines the high-entropy alloy design criteria with the stir friction gradient alloying technology, and can realize the rapid screening and optimization of high-throughput components of the high-entropy alloy; when adding metal elements to different alloy substrates, the alloy components with excellent comprehensive performance can be quickly screened, effectively shortening the screening cycle and reducing costs; the method of the invention pre-buries an isosceles triangle metal plate in a basic high-entropy alloy substrate in an isosceles triangle groove, realizes stir friction gradient alloying by high-speed rotation and movement of a stirring head, controls the thermomechanical coupling effect by adjusting processing parameters (stirring head rotation speed, forward speed, etc.), realizes the integrated regulation of target alloy components and organizations, and realizes the optimal screening and design of alloy components. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic diagram of the friction stir gradient alloying process of Example 1;

[0035] Figure 2 is (Fe of Example 1 40 Mn 20 Co 20 Cr 15 Si5) 100-x Cu x Room temperature tensile curve of the alloy;

[0036] Figure 3 (CoCrFeMnNi) of Example 2 100-x Al x Room temperature tensile curve of the alloy. DETAILED DESCRIPTION

[0037] The inventive concept of the present invention is: utilizing the friction stir gradient alloying derived from the friction stir processing technology, the friction heat and plastic deformation heat generated by the rotation of the stirring head to thermally plasticize the material around the stirring needle, so that the material produces a violent plastic rheology, and the added pure metal and the basic alloy plate are alloyed and violently plastically deformed through the high-temperature thermal coupling effect, so as to achieve microstructure refinement, homogenization and densification. At the same time, by setting an isosceles triangle groove and an isosceles triangle metal plate set in the isosceles triangle groove, it is ensured that the alloy component distribution along the processing direction has a gradient characteristic, and a new alloy plate is prepared by changing the processing parameters, and then the target performance test results including tensile strength and elongation are used to achieve high-throughput alloy component screening. That is, the current situation that the existing friction stir processing technology is mainly used to prepare fine-grained / ultra-fine-grained metal materials and particle-reinforced composite materials can be realized, the application field of the friction stir processing technology can be broadened, and the rapid screening of high-throughput alloy components can be realized, and the outstanding problems of long alloy design and screening cycle and low design success rate existing in the traditional trial and error method for designing alloy components can be solved.

[0038] The following is an explanation of the technical parameters involved in this application:

[0039] High-throughput alloy composition screening: refers to obtaining the most material data with the least number of experiments. Through high-throughput preparation of gradient materials and characterization technology, a large amount of experimental data can be obtained simultaneously, so as to quickly evaluate and screen the composition of alloy materials with the least sample preparation.

[0040] The present invention discloses a high-throughput alloy component screening method based on friction stir gradient alloying, comprising the following steps:

[0041] Step 1: An isosceles triangle groove is formed on the upper surface of the base alloy plate, and the base of the isosceles triangle groove and the vertex of the isosceles triangle groove are located in the same horizontal plane;

[0042] Preferably, the base alloy plate has a thickness of 4 to 10 mm.

[0043] Preferably, the basic alloy plate comprises Fe 40 Mn 20 Co 20 Cr 15 Si5 alloy sheet and CoCrFeMnNi alloy sheet.

[0044] Step 2: adding an isosceles triangle metal plate made of the metal to be added into the isosceles triangle groove, wherein the outer contour of the isosceles triangle metal plate matches the inner contour of the isosceles triangle groove, and the metal to be added can be alloyed with the basic alloy plate;

[0045] Among them: the metal elements to be added that can form the target alloy with the base alloy meet the following conditions:

[0046] and

[0047] Where:

[0048] δ is the atomic radius difference of the target alloy;

[0049] r i is the atomic radius of the i-th element in the target alloy, in nm;

[0050] is the average atomic radius of the target alloy, in nm;

[0051] N is the total number of elements in the target alloy;

[0052] C i is the atomic percentage of the i-th element in the target alloy;

[0053] Ω is the thermodynamic parameter of the target alloy;

[0054] T m is the melting point of the target alloy, in K;

[0055] ΔS mix is the mixing entropy of the target alloy, in J·(K·mol) -1 ;

[0056] ΔH mix is the mixing enthalpy of the target alloy, in J·mol -1 .

[0057] Among them, mixing enthalpy, mixing entropy, atomic radius difference and thermodynamic parameters are all empirical parameters that affect the formation of alloy solid solution phase, and mixing enthalpy and mixing entropy can be determined by existing formulas. When Ω < 1, intermetallic compounds will be formed first, and when Ω ≥ 1.1 and δ ≤ 6.6%, the alloy tends to form a simple solid solution structure with better performance. That is, the metal to be added that meets the above conditions can be alloyed with the basic alloy sheet.

[0058] Preferably, the metal to be added includes Cu, Cr, Ni, Ti and Al.

[0059] Step 3, inserting a stirring needle into the base alloy plate, performing a stir friction gradient alloying treatment on the surface of the base alloy plate, and obtaining a high-flux alloy plate having a gradient distribution of alloy components along a processing direction;

[0060] The friction stir gradient totalization includes at least one friction stir process; the processing path of the stirring head covers the triangular groove; the insertion depth of the stirring needle is the vertical distance from the bottom of the isosceles triangular groove to the upper surface of the base alloy plate;

[0061] Preferably, the amount of the metal to be added is 1 to 30 at. % in atomic percentage.

[0062] Preferably, the stirring head is a W-Re alloy stirring head, which includes a shoulder and a stirring needle. The shoulder has a diameter of 10 to 16 mm, and the stirring needle is conical; the root diameter of the stirring needle is 4 to 8 mm, the top diameter is 3 to 6 mm, and the needle length is 1.5 to 3 mm.

[0063] Preferably, during the friction stir gradient alloying process, the rotation speed of the stirring head is 200 to 1000 r / min, and the forward speed is 10 to 60 mm / min.

[0064] Step 4: sampling the surface of the obtained alloy plate at preset intervals along the length direction to obtain multiple alloy samples; performing component and performance tests on each of the obtained alloy samples, and realizing high-throughput alloy component screening according to the performance test results;

[0065] The performance test includes tensile strength and elongation; the preset interval is 8 to 10 mm.

[0066] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0067] Example 1

[0068] Following the above technical solution, Figure 1 As shown, this embodiment discloses a high-throughput alloy composition screening method based on stir friction gradient alloying, and the basic alloy plate is Fe 40 Mn 20 Co 20 Cr 15 For Si5 alloy plate, the metal to be added is copper with a purity of ≥99.5%, and the designed addition amount of Cu is 1 to 30 at. % based on the atomic percentage of the alloy plate.

[0069] Calculated based on the maximum addition amount of 30 at.%:

[0070]

[0071] is 0.193; N is 6; T m is 1389.29, ΔS mix is 13.49, ΔH mix It is 2620.

[0072]

[0073] According to the calculation results, (Fe 40 Mn 20 Co 20 Cr 15 Si5) 100-x Cu x (x=1-30) satisfies Ω≥1.1, δ≤6.6%, which meets the addition conditions, indicating that as long as the addition amount of Cu is less than or equal to 30at.%, alloying can be performed to form a solid solution target alloy.

[0074] The screening process specifically includes:

[0075] (1) The surface of the base alloy plate is polished with sandpaper to remove the oxide film, and the surface of the base alloy plate is cleaned with acetone. Then, an isosceles triangle groove is opened along the length direction on the upper surface of the base alloy plate with a thickness of 4 mm using a CNC electric spark cutting machine. The length of the base side of the isosceles triangle groove is 1.5 mm, the height is 50 mm, and the vertical distance from the bottom of the isosceles triangle groove to the upper surface of the base alloy plate (i.e., the groove depth) is 1 mm;

[0076] (2) Adding isosceles triangle Cu sheets into the isosceles triangle grooves; in terms of atomic percentage, the amount of copper added is 15 at. % of the final alloy sheet.

[0077] (3) The Fe 40 Mn 20 Co 20 Cr 15 The Si5 alloy plate was placed on the insulating plate surface of the stir friction gradient alloying equipment and fixed on the equipment with a clamp, and then stir friction gradient alloying was performed, wherein the rotation speed of the stirring head was 800r / min and the forward speed was 10mm / min; the alloy composition was obtained with a gradient distribution along the processing direction (Fe 40 Mn 20 Co 20 Cr 15 Si5) 100-x Cu x alloy.

[0078] (4) Sampling was performed on the surface of the obtained high-flux alloy at intervals of 8 mm along the processing direction to obtain four specimens with a length of 17 mm and a width of 8 mm that met the performance test requirements, and they were named S-1, S-2, S-3, and S-4, respectively; the Cu content in each specimen was tested, and the results were 1.6 at.%, 2.4 at.%, 3.2 at.%, and 4.0 at.%, respectively; tensile tests were performed on the four specimens, as shown in FIG. Figure 2 As shown, the tensile strengths are 925.01 MPa, 975.21 MPa, 877.29 MPa and 890.63 MPa, respectively, and the elongations are 26.3%, 33.8%, 23.0% and 15.2%, respectively.

[0079] The above results show that the present embodiment successfully prepared alloys with various compositions based on the friction stir gradient alloying technology, and then the required high-throughput alloy composition can be screened according to the performance test results. According to the above performance test results, in the present embodiment, the tensile strength and elongation are optimized as the standard, and (Fe 40 Mn 20 Co 20 Cr 15 Si5) 97.6 Cu 2.4 It is the alloy component with the best performance.

[0080] Example 2

[0081] The present embodiment discloses a high-throughput alloy component screening method based on stir friction gradient alloying. The method steps of the present embodiment are the same as those of Example 1, except that the CoCrFeMnNi alloy plate is used as the base alloy plate, the base length of the isosceles triangle groove is 1.5 mm, the height is 50 mm, the groove depth is 1 mm, the metal to be added is aluminum, and the purity of the aluminum is ≥99.5%.

[0082] The specific steps are as follows:

[0083] In the target alloy plate, the expected addition amount of the metal Al to be added is 1 to 30 at.%, calculated in atomic percentage, according to the calculation method disclosed in Example 1, with a maximum addition amount of 30 at.% as follows:

[0084]

[0085] is 0.197; N is 6; T m is 1268.16, ΔS mix is 14.45, ΔH mix is -15650.

[0086]

[0087] In this embodiment, (CoCrFeMnNi) is calculated 100-x Al x The mixing enthalpy of (x=1-30) is negative and satisfies Ω≥1.1 and δ≤6.6%, indicating that as long as the addition amount of aluminum is less than or equal to 30at.%, alloying can be performed to generate the solid solution target alloy; the rotation speed of the stirring head is 600r / min, and the forward speed is 50mm / min; sampling is performed at intervals of 10mm along the processing direction on the surface of the obtained high-flux alloy to obtain four samples with a length of 17mm and a width of 8mm that can meet the performance test requirements, and they are named S-1, S-2, S-3, and S-4 respectively; the aluminum content of each sample is then measured in atomic percentage, and the results are 0.8at.%, 1.6at.%, 2.4at.%, and 3.2at.%, respectively;

[0088] Tensile tests were performed on four specimens. Figure 3 As shown, the tensile strengths of the four specimens are 838.70 MPa, 870.10 MPa, 796.20 MPa and 765.21 MPa, respectively, and their elongations are 9.1%, 23.8%, 7.4% and 22.0%, respectively.

[0089] The above results show that this embodiment successfully prepared alloys with various compositions based on the friction stir gradient alloying technology, and then the required high-throughput alloy composition can be screened according to the performance test results. According to the above performance test results, in this embodiment, the tensile strength and elongation are optimized as the standard, and (CoCrFeMnNi) is screened. 98.4 Al 1.6 It is the alloy component with the best performance.

[0090] It can be seen from Examples 1 to 2 that the method of the present invention can be used to perform high-throughput alloy composition screening by using friction stir gradient alloying.

[0091] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, all equivalent changes made to the contents described in the claims of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A high-throughput alloy composition screening method based on stir friction gradient alloying, characterized in that: The following steps are involved: Step 1: An isosceles triangle groove is formed on the upper surface of the base alloy plate, and the base of the isosceles triangle groove and the vertex of the isosceles triangle groove are located in the same horizontal plane; Step 2: adding an isosceles triangle metal plate made of the metal to be added into the isosceles triangle groove, wherein the outer contour of the isosceles triangle metal plate matches the inner contour of the isosceles triangle groove, and the metal to be added can be alloyed with the basic alloy plate; Step 3, inserting a stirring needle into the base alloy plate, and performing a stirring friction gradient alloying treatment on the area where the isosceles triangle groove is located, to obtain an alloy plate in which the alloy composition is gradiently distributed along the bottom edge of the isosceles triangle groove to the top angle of the isosceles triangle groove; The friction stir gradient totalization includes at least one friction stir treatment; the insertion depth of the stirring needle is the vertical distance from the bottom of the isosceles triangle groove to the upper surface of the base alloy plate; Step 4: sampling the surface of the obtained alloy plate at preset intervals along the length direction to obtain multiple alloy samples; performing component and performance tests on each of the obtained alloy samples, and realizing high-throughput alloy component screening according to the performance test results; The performance tests include tensile strength and elongation.

2. The high-throughput alloy composition screening method based on friction stir gradient alloying according to claim 1, characterized in that: The metal element to be added meets the following conditions: and Where: δ is the atomic radius difference of the target alloy; r i is the atomic radius of the i-th element in the target alloy, in nm; is the average atomic radius of the target alloy, in nm; N is the total number of elements in the target alloy; C i is the atomic percentage of the i-th element in the target alloy; Ω is the thermodynamic parameter of the target alloy; T m is the melting point of the target alloy, in K; ΔS mix is the mixing entropy of the target alloy, in J·(K·mol) -1 ; ΔH mix is the mixing enthalpy of the target alloy, in J·mol -1 .

3. The high-throughput alloy composition screening method based on friction stir gradient alloying according to claim 1, characterized in that: The thickness of the basic alloy plate is 4 to 10 mm.

4. The high-throughput alloy composition screening method based on stir friction gradient alloying according to claim 1, characterized in that: In the alloy plate described in step 3, the amount of the metal to be added is 1 to 30 at. % in atomic percentage.

5. The high-throughput alloy composition screening method based on friction stir gradient alloying according to claim 1, characterized in that: The metals to be added include Cu, Cr, Ni, Ti and Al.

6. The high-throughput alloy composition screening method based on stir friction gradient alloying according to claim 1, characterized in that: The stirring head is a W-Re alloy stirring head, which includes a shoulder and a stirring needle. The diameter of the shoulder is 10-16 mm, and the stirring needle is conical; the root diameter of the stirring needle is 4-8 mm, the top diameter is 3-6 mm, and the needle length is 1.5-3 mm.

7. The high-throughput alloy composition screening method based on stir friction gradient alloying according to claim 1, characterized in that: In the friction stir gradient alloying, the rotation speed of the stirring head is 200 to 1000 r / min, and the forward speed is 10 to 60 mm / min.

8. The high-throughput alloy composition screening method based on friction stir gradient alloying according to claim 1, characterized in that: The preset interval in step 4 is 8 to 10 mm.

9. The high-throughput alloy composition screening method based on friction stir gradient alloying according to claim 1, characterized in that: The basic alloy plate includes Fe 40 Mn 20 Co 20 Cr 15 Si5 alloy sheet and CoCrFeMnNi alloy sheet.

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