(Ti-Al) x (Ni-Cr) y (Co-V) z eutectic high-entropy alloy and heat treatment process thereof

Abstract

The invention discloses a heat treatment process of a (Ti-Al) x (Ni-Cr) y (Co-V) z eutectic high-entropy alloy. Compared with 316L, the material disclosed by the invention has the advantages in corrosion resistance, mechanical property and the like, has a good development prospect in marine application materials in the ocean, and also has very important reference value for subsequent design and application of eutectic high-entropy alloy.

Description

Technical Field

[0001] The present invention belongs to the technical field of eutectic high entropy alloys, and particularly relates to the field of heat treatment technology of (Ti-Al)x(Ni-Cr)y(Co-V)z eutectic high entropy alloys. Background Art

[0002] Traditional binary eutectic alloys, such as Al-Si, Ti-Si, Al-Cu, and Fe-C, are widely used in key complex components in fields such as vehicle engineering, warships, submarines, and aerospace due to their excellent cast fluidity, uniform microstructure, and minimal casting defects. Eutectic alloys not only enable the one-piece molding of complex structural components, eliminating the tedious steps of machining and joining processes, but also ensure the uniformity of composition, microstructure, and performance of each part of the complex structural component, thereby increasing the safety and reliability of the material in service. However, the relatively low mechanical properties of traditional binary eutectic alloys (for example, the tensile strength and elongation at break of the Al-Si eutectic are only 350 MPa and approximately 5%) limit their engineering applications under more severe service conditions.

[0003] To address these issues, Lu Yiping et al. proposed the concept of eutectic high-entropy alloys in 2014 (A Promising New Class of High-Temperature Alloys: Eutectic High-Entropy Alloys, Scientific Reports (2014)). They successfully designed an AlCoCrFeNi2.1 eutectic high-entropy alloy composed of a face-centered cubic disordered solid solution phase and a B2 phase. This eutectic high-entropy alloy exhibits high tensile strength and good fracture toughness, thanks to the soft face-centered cubic disordered solid solution phase providing plasticity and the hard B2 phase enhancing strength. Furthermore, the eutectic reaction improves the alloy's casting fluidity and compositional segregation. In recent years, the eutectic high-entropy alloy system has rapidly developed and expanded. Regarding the mechanical properties of the eutectic high-entropy alloys reported to date, the vast majority exhibit a good balance between strength and plasticity only during compression; few exhibit excellent strength and toughness. Therefore, the design of new eutectic high-entropy alloy systems with excellent strength and toughness remains a significant challenge. Furthermore, current research on eutectic high-entropy alloys primarily focuses on the as-cast state, with relatively little research on their heat treatment processes. As a means of optimizing alloy properties, the impact of heat treatment on the microstructure and mechanical properties of eutectic high-entropy alloys is also a topic worth exploring. Summary of the Invention

[0004] The purpose of the present invention is to solve the deficiencies in the above-mentioned prior art and provide a (Ti-Al)x(Ni-Cr)y(Co-V)z eutectic high entropy alloy heat treatment process. The eutectic high entropy alloy obtained by the treatment of the present invention has excellent toughness and maintains high tensile strength while maintaining good yield strength.

[0005] The present invention achieves the above-mentioned purpose through the following technical solution: a (Ti-Al)x(Ni-Cr)y(Co-V)z eutectic high entropy alloy, calculated according to the molar ratio, wherein X=0.5~2.0, Y=0.5~2.0, Z=0~2.0, preferably X=0.8~2.0, Y=1.5~2.0, Z=1.5~2.0.

[0006] In certain technical solutions of the present invention, the (Ti-Al)x(Ni-Cr)y(Co-V)z eutectic high entropy alloy is any one of the following: (Ti-Al) 0.5 (Ni-Cr) 0.5 ; (Ti-Al) 1.5 (Ni-Cr) 1.5 (Co-V) 1.5 ; (Ti-Al) 2.0 (Ni-Cr) 2.0 (Co-V) 1.5 ; (Ti-Al) 2.0 (Ni-Cr) 2.0 ; (Ti-Al) 0.8 (Ni-Cr) 2.0 (Co-V) 2.0 .

[0007] According to the second aspect of the present invention, the present invention provides a heat treatment process method for a (Ti-Al)x(Ni-Cr)y(Co-V)z eutectic high entropy alloy, comprising the following steps: preparing raw materials according to a molar ratio and then performing heat treatment in a heat treatment furnace.

[0008] Preferably, the heat treatment furnace is a box-type heat treatment furnace for sequentially performing primary and secondary heat treatments; the primary heat treatment temperature is 800-900°C for 10-14 hours; the secondary heat treatment temperature is 1150-1300°C for 6-10 hours; and the furnace is cooled after heat treatment.

[0009] Preferably, the eutectic high entropy alloy contains two phases, FCC and BCC (face-centered cubic lattice FCC and BCC body-centered cubic lattice), and the eutectic width is 0.75 to 0.85 μm.

[0010] Preferably, the eutectic high-entropy alloy casting has high mechanical properties and / or corrosion resistance at room temperature. Further preferably, the eutectic high-entropy alloy has a yield strength of 1000-1300 MPa and a tensile strength of 1300-1600 MPa; a corrosion potential of 1.5-2.0 V in seawater; and corrosion resistance superior to 316L stainless steel.

[0011] According to the third aspect of the present invention, the (Ti-Al)x(Ni-Cr)y(Co-V)z eutectic high entropy alloy described in the first aspect of the present invention is used to prepare ship materials.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] 1. The eutectic high-entropy alloy of the present invention exhibits a typical lamellar eutectic structure in the cast state. Through heat treatment, the eutectic second phase transforms from a sharp, long strip morphology to a rounded, granular morphology, so that the eutectic high-entropy alloy maintains a good yield strength of 1000-1300 MPa while still maintaining a high tensile strength of 1300-1600 MPa;

[0014] 2. The eutectic high-entropy alloy of the present invention not only has excellent casting fluidity, enabling the integrated molding of complex structural parts, but also has a uniform microstructure and few casting defects, which improves its safety and reliability in engineering.

[0015] 3. The heat treatment process for preparing the eutectic high entropy alloy of the present invention is simple, safe and reliable; the raw materials used are non-toxic and harmless, easy to obtain, and suitable for promotion and use. DETAILED DESCRIPTION

[0016] The performance test method is completed with reference to the following prior art teachings:

[0017] (1) Yield strength is based on GB / T 228.1-2021;

[0018] (2) Tensile strength is based on GB / T 228.1-2021;

[0019] (3) The corrosion potential in seawater adopts GB / T 40299-2021.

[0020] Implementation Method 1 (Ti-Al) 0.5 (Ni-Cr) 0.5 Corrosion-resistant quaternary eutectic high entropy alloy

[0021] The (Ti-Al) with excellent mechanical properties 0.5 (Ni-Cr) 0.5 A heat treatment process for a corrosion-resistant eutectic high-entropy alloy comprises the following steps:

[0022] The heat treatment furnace is a box-type heat treatment furnace, the first-level heat treatment temperature is 800°C, the time is 1 hour; the second-level heat treatment temperature is 1150°C, the time is 10 hours, and the furnace is cooled.

[0023] The novel corrosion-resistant eutectic high-entropy alloy with excellent mechanical properties designed by the method contains two phases (FCC and BCC), and the eutectic width is 0.8 μm.

[0024] The resulting eutectic high-entropy alloy casting exhibits high mechanical properties and corrosion resistance at room temperature. Its yield strength can reach 1150 MPa and its tensile strength can reach 1350 MPa. Its corrosion potential in seawater is 1.8 V, and its corrosion resistance is superior to that of 316L stainless steel.

[0025] Embodiment 2 (Ti-Al) 1.5 (Ni-Cr) 1.5 (Co-V) 1.5 Corrosion-resistant eutectic high entropy alloy

[0026] The (Ti-Al) with excellent mechanical properties 1.5 (Ni-Cr) 1.5 (Co-V) 1.5 A heat treatment process for a corrosion-resistant eutectic high-entropy alloy comprises the following steps:

[0027] The heat treatment furnace is a box-type heat treatment furnace, the first-level heat treatment temperature is 900°C, the time is 12h; the second-level heat treatment temperature is 1200°C, the time is 8h, and the furnace is cooled.

[0028] The novel corrosion-resistant eutectic high-entropy alloy with excellent mechanical properties designed by the method contains two phases (FCC and BCC), and the eutectic width is 0.8 μm.

[0029] The resulting eutectic high-entropy alloy casting exhibits high mechanical properties and corrosion resistance at room temperature. Its yield strength can reach 1200 MPa and its tensile strength can reach 1400 MPa. Its corrosion potential in seawater is 1.7 V, and its corrosion resistance is superior to that of 316L stainless steel.

[0030] Implementation Method 3 (Ti-Al) 2.0 (Ni-Cr) 2.0 (Co-V) 1.5 Corrosion-resistant eutectic high entropy alloy

[0031] The (Ti-Al) with excellent mechanical properties 2.0 (Ni-Cr) 2.0 (Co-V) 1.5 A heat treatment process for a corrosion-resistant eutectic high-entropy alloy comprises the following steps:

[0032] The heat treatment furnace is a box-type heat treatment furnace, the first-level heat treatment temperature is 900°C, the time is 14 hours; the second-level heat treatment temperature is 1300°C, the time is 10 hours, and the furnace is cooled.

[0033] The new corrosion-resistant eutectic high-entropy alloy with excellent mechanical properties designed by the above method contains two phases (FCC and BCC), and the eutectic width is 0.85μm.

[0034] The resulting eutectic high-entropy alloy casting exhibits high mechanical properties and corrosion resistance at room temperature. Its yield strength can reach 1300 MPa and its tensile strength can reach 1600 MPa. Its corrosion potential in seawater is 2.0 V, and its corrosion resistance is superior to that of 316L stainless steel.

[0035] Embodiment 4 (Ti-Al) 2.0 (Ni-Cr) 2.0 Corrosion-resistant eutectic high entropy alloy

[0036] Excellent mechanical properties (Ti-Al) 2.0 (Ni-Cr) 2.0 A heat treatment process for a corrosion-resistant eutectic high-entropy alloy comprises the following steps:

[0037] The heat treatment furnace is a box-type heat treatment furnace, the first-level heat treatment temperature is 900°C, the time is 11 hours; the second-level heat treatment temperature is 1200°C, the time is 9 hours, and the furnace is cooled.

[0038] The novel corrosion-resistant eutectic high-entropy alloy with excellent mechanical properties designed by the method contains two phases (FCC and BCC), and the eutectic width is 0.81 μm.

[0039] The new eutectic high-entropy alloy designed using this method exhibits high mechanical properties and corrosion resistance at room temperature. The yield strength can reach 1250 MPa and the tensile strength can reach 1550 MPa. The corrosion potential in seawater is 1.9 V, and the corrosion resistance is superior to that of 316L stainless steel.

[0040] Implementation Method 5 (Ti-Al) 0.8 (Ni-Cr) 2.0 (Co-V) 2.0 Corrosion-resistant eutectic high entropy alloy

[0041] The (Ti-Al) with excellent mechanical properties 0.8 (Ni-Cr) 2.0 (Co-V) 2.0 A heat treatment process for a corrosion-resistant eutectic high-entropy alloy comprises the following steps:

[0042] The heat treatment furnace is a box-type heat treatment furnace, the first-level heat treatment temperature is 850°C, the time is 12 hours; the second-level heat treatment temperature is 1300°C, the time is 10 hours, and the furnace is cooled.

[0043] The novel corrosion-resistant eutectic high-entropy alloy with excellent mechanical properties designed by the method contains two phases (FCC and BCC) and the eutectic width is 0..79μm.

[0044] The new eutectic high-entropy alloy designed by this method exhibits high mechanical properties and corrosion resistance at room temperature. The yield strength can reach 1150 MPa and the tensile strength can reach 1400 MPa. The corrosion potential in seawater is 1.5 V, and the corrosion resistance is superior to that of 316L stainless steel.

[0045] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A (Ti-Al)x(Ni-Cr)y(Co-V)z eutectic high entropy alloy, wherein X=0.5~2.0, Y=0.5~2.0, and Z=0~2.

0.

2. The (Ti-Al)x(Ni-Cr)y(Co-V)z eutectic high entropy alloy according to claim 1, wherein X=0.8~2.0, Y=1.5~2.0, and Z=1.5~2.

0.

3. The (Ti-Al)x(Ni-Cr)y(Co-V)z eutectic high entropy alloy according to claim 1 or 2, which is any one of the following: (Ti - Al) 0.5 (Ni - Cr) 0.5 ; (Ti - Al) 1.5 (Ni - Cr) 1.5 (Co - V) 1.5 ; (Ti - Al) 2.0 (Ni - Cr) 2.0 (Co - V) 1.5 ; (Ti - Al) 2.0 (Ni - Cr) 2.0 or (Ti - Al) 0.8 (Ni - Cr) 2.0 (Co - V) 2.0 .

4. A heat treatment process for the (Ti-Al)x(Ni-Cr)y(Co-V)z eutectic high entropy alloy according to claim 1, characterized in that: After the raw materials are prepared according to the molar ratio, heat treatment is carried out in a heat treatment furnace.

5. The method according to claim 4, The heat treatment furnace is a box-type heat treatment furnace that performs primary heat treatment and secondary heat treatment in sequence. The primary heat treatment temperature is 800-900°C and the time is 10-14 hours; the secondary heat treatment temperature is 1150-1300°C and the time is 6-10 hours; after the heat treatment is completed, the furnace is cooled.

6. A method according to claim 5, characterized in that: The eutectic high entropy alloy contains two phases, FCC and BCC, and the eutectic width is 0.75 to 0.85 μm.

7. A method according to claim 6, characterized in that: The eutectic high entropy alloy casting obtained by the design has high mechanical properties and corrosion resistance at room temperature.

8. The method according to claim 7, characterized in that: The eutectic high-entropy alloy casting obtained by the design can achieve a yield strength of 1000-1300 MPa and a tensile strength of 1300-1600 MPa; the corrosion potential in seawater is 1.5-2.0 V; and the corrosion performance is better than that of 316L stainless steel.

9. Use of the (Ti-Al)x(Ni-Cr)y(Co-V)z eutectic high entropy alloy according to claim 1 for preparing shipbuilding materials.