AlCrMoNbTiZr light multi-principal-element alloy with work hardening capacity and preparation method and application of AlCrMoNbTiZr light multi-principal-element alloy

Abstract

The invention provides an AlCrMoNbTiZr light multi-principal-element alloy with work hardening capacity, and a preparation method and application of the AlCrMoNbTiZr light multi-principal-element alloy. The general formula of the AlCrMoNbTiZr light multi-principal-element alloy with the work hardening capacity is AlaCrbMocNbd (Ti60Zr40) 100-a-b-c-d, a is larger than or equal to 2at.% and smaller than or equal to 6at.%, b is larger than or equal to 0.1 at.% and smaller than or equal to 0.4 at.%, c is larger than or equal to 0.1 at.% and smaller than or equal to 0.4 at.%, and d is larger than or equal to 2at.% and smaller than or equal to 8at.%. According to the alloy, through alloy component control, the room-temperature tensile mechanical property is considered on the basis of keeping certain work hardening capacity. The AlCrMoNbTiZr light multi-principal-element alloy with the work hardening capacity has the advantages that the density is low, the room-temperature mechanical property is good, the work hardening capacity is excellent, and the industrial application of the light multi-principal-element alloy is expected to be promoted.

Description

Technical Field

[0001] The present invention relates to alloy technology, and in particular to an AlCrMoNbTiZr lightweight multi-principal-element alloy with work hardening capability, a preparation method thereof and use thereof. Background Art

[0002] The aerospace and defense industries are increasingly in need of new lightweight structural materials. The common material for the tail nozzles of rockets and aircraft in the aerospace field is GH3625 high-temperature alloy (density > 8.44g / cm 3 ) and refractory pure metals (>8g / cm 3 ), but they all have high density; light tanks and light mortars in the defense industry have become important equipment to improve combat mobility. The alloy materials used in these fields are required to have lower density and higher strength and plasticity.

[0003] The emergence of lightweight high-entropy alloys provides a new alloy design strategy to solve this problem. It is expected that low-density and high-strength and plastic alloy materials can be prepared through the synergistic effect between multiple principal components. However, most of the lightweight multi-principal component alloys reported so far do not have work hardening ability, which is manifested as premature necking. It is expected that the composition of lightweight multi-principal component alloys can be regulated to improve their work hardening ability by using the method of phase transformation induced plasticity. Summary of the invention

[0004] The purpose of the present invention is to solve the problem of poor work hardening ability of current lightweight high entropy alloys and propose an AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability. The alloy is controlled by alloy composition, and takes into account the room temperature tensile mechanical properties while maintaining a certain work hardening ability. The AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability of the present invention has low density, good room temperature mechanical properties and excellent work hardening ability, and is expected to promote the industrial application of lightweight high entropy alloys.

[0005] It should be noted that, in the present invention, unless otherwise specified, the specific meaning of "including" in relation to composition limitations and descriptions includes both open-ended "including", "comprising", etc. and similar meanings, as well as closed-ended "composed of", "composed of", etc. and similar meanings.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a lightweight multi-principal alloy of AlCrMoNbTiZr with work hardening ability, the general formula is Al a Cr b Mo c Nb d (Ti 60 Zr 40 )100-a-b-c-d , among which, 2at.%≤a≤6at.%, ​​0.1at.%≤b≤0.4at.%, ​​0.1at.%≤c≤0.4at.%, ​​2at.%≤d≤8at.%.

[0007] Furthermore, in the general formula, preferably: 3at.%≤a≤6at.%, 0.1at.%≤b≤0.3at.%, 0.1at.%≤c≤0.3at.%, 3at.%≤d≤6at.%.

[0008] Furthermore, the AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability consists of two phases: HCP and BCC.

[0009] Furthermore, the AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability has a density of ρ≤5.5g / cm 3 .

[0010] Furthermore, the AlCrMoNbTiZr lightweight multi-principal element alloy with work hardening ability has a room temperature tensile yield strength of 489MPa to 987MPa, a tensile strength of 1126MPa to 1171MPa, an elongation at break of 17.9% to 23.0%, and a uniform elongation under true stress strain of 10.0% to 11.5%.

[0011] Another object of the present invention is to disclose a method for preparing a lightweight AlCrMoNbTiZr multi-principal alloy with work hardening capability, comprising the following steps:

[0012] Weigh the raw materials according to the general formula: pure metal particles of Al, Cr, Mo, Nb, Ti and Zr, place the raw materials in a copper crucible; place the pure titanium ingot in another copper crucible; close the vacuum chamber, evacuate the vacuum chamber, and wait until the digital vacuum gauge shows 5.0×10 -3 ~5.5×10 -3 After reaching Pa, stop evacuating, open the charging valve, and fill in high-purity argon to -0.07~0.05MPa; before starting to smelt the alloy, first smelt the pure Ti ingot to absorb excess oxygen in the furnace chamber; then smelt the raw materials to obtain a lightweight multi-principal alloy button ingot.

[0013] Furthermore, the present invention uses pure metal particles of Al, Cr, Mo, Nb, Ti and Zr as raw materials. The purity of raw material Al particles is greater than or equal to 99.99wt.%, the purity of Nb and Cr particles is greater than or equal to 99.95wt.%, and the purity of Ti and Zr particles is greater than or equal to 99.9wt.%. The raw material weighing error is ±0.001g.

[0014] Furthermore, before smelting, the raw materials are placed in alcohol for ultrasonic cleaning to remove stains on the surface of the pure metal particles; after the cleaned pure metal raw materials are fully dried, they are respectively packed into sealed bags for standby use.

[0015] Furthermore, the smelting adopts a vacuum non-consumable arc furnace.

[0016] Furthermore, during smelting, pure metal particles of Al, Cr and Ti with low melting points are placed at the bottom of the copper crucible, and pure metal particles of Mo, Nb and Zr with high melting points are placed at the top.

[0017] Furthermore, the Ti ingot is smelted 1 to 3 times, each time for 60 to 90 seconds, to absorb the residual oxygen in the furnace chamber and prevent the ingot from being oxidized.

[0018] Furthermore, when the alloy is smelted, it is smelted 5 to 7 times, and turned over after each smelting. The smelting time for each time is 120 to 180 seconds, and the current is controlled at 270 to 300A.

[0019] Furthermore, during smelting, the ingot is first melted by an electric arc, and then the melt is stirred by electromagnetic stirring, with a current frequency of 3 to 5 Hz to ensure uniformity of the alloy composition.

[0020] Another object of the present invention is to disclose the use of a lightweight multi-principal-component AlCrMoNbTiZr alloy with work hardening capability in the fields of aerospace and lightweight military equipment.

[0021] The AlCrMoNbTiZr lightweight multi-principal alloy with work hardening capability of the present invention has the following advantages compared with the prior art:

[0022] 1) The density of the AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability of the present invention is 5.2-5.5 g / cm 3 , with a biphasic structure of BCC and HCP;

[0023] 2) The AlCrMoNbTiZr lightweight multi-principal alloy with work hardening capability of the present invention has a yield strength of 489MPa to 987MPa, a tensile strength of 1126MPa to 1171MPa, an elongation at break of 17.9% to 23.0%, and a uniform elongation under true stress strain of 10.0% to 11.5%.

[0024] The AlCrMoNbTiZr lightweight multi-principal alloy with work-hardening ability of the present invention has low density, good room temperature mechanical properties and excellent work-hardening ability, and is expected to promote the industrial application of lightweight high-entropy alloys. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1Al3Cr prepared in Example 1 of the present invention 0.1 Mo 0.1 Nb3(Ti 60 Zr 40 ) 93.8 XRD patterns of lightweight multi-principal alloys;

[0026] Figure 2 Al3Cr prepared in Example 1 of the present invention 0.1 Mo 0.1 Nb3(Ti 60 Zr 40 ) 93.8 Microstructure of lightweight multi-principal alloys;

[0027] Figure 3 Al3Cr prepared in Example 1 of the present invention 0.1 Mo 0.1 Nb3(Ti 60 Zr 40 ) 93.8 Tensile engineering stress-strain curves of lightweight multi-principal element alloys.

[0028] Figure 4 Al3Cr prepared in Example 2 of the present invention 0.1 Mo 0.1 Nb5(Ti 60 Zr 40 ) 91.8 XRD pattern of lightweight multi-principal component alloy.

[0029] Figure 5 Al3Cr prepared in Example 2 of the present invention 0.1 Mo 0.1 Nb5(Ti 60 Zr 40 ) 91.8 Microstructure of lightweight multi-principal alloys;

[0030] Figure 6 Al3Cr prepared in Example 2 of the present invention 0.1 Mo 0.1 Nb5(Ti 60 Zr 40 ) 91.8 Tensile engineering stress-strain curves of lightweight multi-principal element alloys. DETAILED DESCRIPTION

[0031] The present invention is further described below with reference to the examples. The description of the technical features described below is based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that:

[0032] Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values ​​and numerical ranges appearing in the present invention should be understood to include the inevitable systematic errors in industrial production.

[0033] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints numerical values ​​A and B.

[0034] In the present specification, a numerical range expressed using "above" or "below" means a numerical range including the number.

[0035] In this specification, the word "may" means both performing a certain process and not performing a certain process.

[0036] In this specification, the use of "optional" or "optional" indicates that certain substances, components, execution steps, application conditions and other factors are used or not used.

[0037] In this specification, when "normal temperature" or "room temperature" is used, the temperature may be 15-25°C.

[0038] In this manual, the reagents or instruments used without indicating the manufacturer are all conventional products that can be obtained through commercial purchase.

[0039] Example 1

[0040] This embodiment discloses a lightweight multi-principal alloy of AlCrMoNbTiZr with work hardening capability, the chemical formula of which is Al3Cr 0.1 Mo 0.1 Nb3(Ti 60 Zr 40 ) 93.8 .

[0041] In this embodiment, the preparation method of the AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability comprises the following steps:

[0042] Step 1, raw material preparation: select pure metal particles of Al, Cr, Mo, Nb, Ti and Zr as raw materials; perform ultrasonic cleaning on the selected pure metal raw materials in alcohol to remove stains on the surface of the pure metal particles; after the cleaned pure metal raw materials are fully dried, they are respectively packed into sealed bags for standby use;

[0043] Step 2, ingredients: Convert the designed lightweight multi-principal alloy into specific ingredient mass according to the molar ratio of the elements in the chemical formula. The total mass of the alloy ingot is 50g. The specific masses of the pure metal particles of Al, Cr, Mo, Nb, Ti and Zr are calculated to be 0.623g, 0.040g, 0.074g, 2.142g, 20.757g and 26.364g respectively. Then use an electronic balance to weigh the pretreated pure metal with a weighing error of ±0.001g. Place the weighed pure metal particles in a sample bag for later use;

[0044] Step 3: Place the prepared raw materials in step 2 into a copper crucible of a vacuum arc furnace, place low melting point Al, Cr and Ti elements at the bottom of the copper crucible, and high melting point Mo, Nb and Zr elements at the top; evacuate to 5.5×10 -3 Pa, and then fill with argon to -0.06MPa; during smelting, first melt the pure Ti ingot, and repeat the smelting twice, each smelting for 60s to absorb the residual oxygen in the furnace chamber, then melt the lightweight multi-principal alloy, and repeat the smelting for 5 times. The smelting current is controlled at 290A, and each melting arc should last for 150s and the electromagnetic stirring should be turned on to 4Hz to ensure the composition uniformity of the lightweight multi-principal alloy.

[0045] The phase composition, microstructure and mechanical properties of the lightweight multi-principal alloy disclosed in Example 1 were tested. Figure 1 Al3Cr 0.1 Mo 0.1 Nb3(Ti 60 Zr 40 ) 93.8 XRD spectrum of lightweight multi-principal alloy. It can be seen from the spectrum that Al3Cr 0.1 Mo 0.1 Nb3(Ti 60 Zr 40 ) 93.8 The lightweight multi-principal alloy has a BCC and HCP dual-phase structure; Figure 2 Al3Cr 0.1 Mo 0.1 Nb3(Ti 60 Zr 40 ) 93.8 The backscattered electron image of the microstructure of the lightweight multi-principal alloy shows that the AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability presents a long strip structure; Figure 3 Al3Cr 0.1 Mo 0.1 Nb3(Ti 60 Zr 40 ) 93.8The tensile engineering stress-strain curve of the cast lightweight multi-principal alloy shows that at room temperature, the yield strength of the work-hardening AlCrMoNbTiZr lightweight multi-principal alloy is 987MPa, the tensile strength is 1171MPa, the elongation after fracture is 17.9%, and the uniform elongation under true stress-strain is 10%.

[0046] Example 2

[0047] This embodiment provides a lightweight AlCrMoNbTiZr multi-principal alloy with work hardening capability, and its chemical formula is Al3Cr 0.1 Mo 0.1 Nb5(Ti 60 Zr 40 ) 91.8 The preparation method of the alloy is the same as that of Example 1.

[0048] Figure 4 Al3Cr 0.1 Mo 0.1 Nb5(Ti 60 Zr 40 ) 91.8 XRD spectrum of lightweight multi-principal alloy. It can be seen from the spectrum that Al3Cr 0.1 Mo 0.1 Nb5(Ti 60 Zr 40 ) 91.8 The lightweight multi-principal alloy has a BCC and HCP dual-phase structure; Figure 5 Al3Cr 0.1 Mo 0.1 Nb5(Ti 60 Zr 40 ) 91.8 The backscattered electron image of the microstructure of the lightweight multi-principal alloy shows that the AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability presents a long strip structure; Figure 6 Al3Cr 0.1 Mo 0.1 Nb5(Ti 60 Zr 40 ) 91.8 The tensile engineering stress-strain curve of the cast lightweight multi-principal alloy shows that at room temperature, the yield strength of the work-hardening AlCrMoNbTiZr lightweight multi-principal alloy is 489MPa, the tensile strength is 1126MPa, the elongation after fracture is 23.0%, and the uniform elongation under true stress-strain is 11.5%.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A lightweight multi-principal alloy of AlCrMoNbTiZr with work hardening capability, characterized in that: The general formula is Al a Cr b Mo c Nb d (Ti 60 Zr 40 ) 100-a-b-c-d , among which, 2at.%≤a≤6at.%, ​​0.1at.%≤b≤0.4at.%, ​​0.1at.%≤c≤0.4at.%, ​​2at.%≤d≤8at.%.

2. The AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability according to claim 1, characterized in that: The AlCrMoNbTiZr lightweight multi-principal alloy with work hardening capability consists of two phases, HCP and BCC.

3. The AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability according to claim 1, characterized in that: The AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability has a density of ρ≤5.5g / cm 3 .

4. The AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability according to claim 1, characterized in that: The AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability has a room temperature tensile yield strength of 489MPa-987MPa, a tensile strength of 1126MPa-1171MPa, a fracture elongation of 17.9%-23.0%, and a uniform elongation under true stress strain of 10.0%-11.5%.

5. A method for preparing the AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability according to any one of claims 1 to 4, characterized in that: The following steps are involved: Weigh the raw materials according to the general formula: pure metal particles of Al, Cr, Mo, Nb, Ti and Zr, place the raw materials in a copper crucible; place the pure titanium ingot in another copper crucible; close the vacuum chamber, evacuate the vacuum chamber, and wait until the digital vacuum gauge shows 5.0×10 -3 ~5.5×10 -3 After reaching Pa, stop evacuating, open the charging valve, and fill in high-purity argon to -0.07~0.05MPa; before starting to smelt the alloy, first smelt the pure Ti ingot to absorb excess oxygen in the furnace chamber; then smelt the raw materials to obtain a lightweight multi-principal alloy button ingot.

6. The method for preparing the AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability according to claim 5, characterized in that: The smelting adopts a vacuum non-consumable arc furnace.

7. The method for preparing the AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability according to claim 5, characterized in that: During smelting, low-melting-point Al, Cr and Ti pure metal particles are placed at the bottom of the copper crucible, and high-melting-point Mo, Nb and Zr pure metal particles are placed at the top.

8. The method for preparing the AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability according to claim 5, characterized in that: Smelt the Ti ingot 1 to 3 times, each time for 60 to 90 seconds; When the alloy is smelted, it is smelted 5 to 7 times, and it is turned over after each smelting. The smelting time for each time is 120 to 180 seconds, and the current is controlled at 270 to 300A.

9. The method for preparing the AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability according to claim 5, characterized in that During smelting, the ingot is first melted with an electric arc, and then the electromagnetic stirring is turned on to stir the melt, with the current frequency being 3 to 5 Hz.

10. Use of the AlCrMoNbTiZr lightweight multi-principal alloy with work hardening ability as claimed in any one of claims 1 to 4 in the fields of aerospace and lightweight military equipment.

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