An ultra-high strength lightweight Al-Ti-V-Cr medium-entropy alloy

Abstract

This application discloses an ultra-high strength, lightweight Al-Ti-V-Cr medium-entropy alloy in the field of medium-entropy alloy materials technology. The alloy comprises, by mass percentage: Al: 24–28%; Ti: 45–50%; V: 10–14%; Cr: 10–14%; and the total content of impurity elements is ≤0.01%. This technical solution obtains a medium-entropy alloy by mixing the four elements in a certain proportion, giving it characteristics such as ultra-high strength, low density, high temperature resistance, and excellent hot workability.

Description

Technical Field

[0001] This invention relates to the field of medium-entropy alloy materials technology, specifically to an ultra-high strength lightweight Al-Ti-V-Cr medium-entropy alloy. Background Technology

[0002] With the rapid development of high-end equipment in aerospace, weaponry, and other fields, the physicochemical properties of traditional alloys are increasingly unable to meet the corresponding design requirements. Therefore, in the 1990s, a new design concept of "multi-element high-entropy alloys" or "multi-element high-disorder alloys" was proposed, which is different from traditional alloys. This involves mixing multiple elements in equiatomic or near-equiatomic ratios to prepare alloys. By increasing the overall entropy value of the alloy system, high-entropy alloys are obtained, possessing special physicochemical properties that surpass the limits of traditional alloys, such as ultra-high strength and hardness, wear and corrosion resistance, high-temperature oxidation resistance, high-temperature softening resistance, and ultra-low temperature impact resistance. Medium-entropy alloys have entropy values ​​between high-entropy alloys and traditional alloys (low-entropy alloys). They possess some superior properties that high-entropy alloys have but traditional alloys cannot match. Furthermore, medium-entropy alloys have relatively fewer elemental types compared to high-entropy alloys, making analysis and research easier.

[0003] Therefore, this application provides a novel Al-Ti-V-Cr medium-entropy alloy, which obtains a medium-entropy alloy by mixing the four elements in a certain proportion, giving it the characteristics of ultra-high strength, low density, high temperature resistance, and excellent hot workability. Summary of the Invention

[0004] The present invention aims to provide an ultra-high strength lightweight Al-Ti-V-Cr medium-entropy alloy, which obtains a medium-entropy alloy by mixing the four elements in a certain proportion, thus giving it the characteristics of ultra-high strength, low density, high temperature resistance and excellent hot workability.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An ultra-high strength lightweight Al-Ti-V-Cr medium-entropy alloy, comprising by mass percentage: Al: 24~28%; Ti: 45~50%; V: 10~14%; Cr: 10~14%; and total impurity element content ≤0.01%.

[0007] The optimized composition, by mass percentage, includes: Al: 26~28%; Ti: 46~48%; V: 10~14%; Cr: 10~14%; and the total content of impurity elements is ≤0.01%.

[0008] The optimized composition, by mass percentage, includes: Al: 24~28%; Ti: 45~50%; V: 12~13%; Cr: 12~13%; and the total content of impurity elements is ≤0.01%.

[0009] The optimized impurity elements are H, O, N, Fe, and Si.

[0010] The optimized medium-entropy alloy exhibits a room temperature strength > 1.67 GPa, a hardness of 400~600 HV, and a density ≤ 4.3 g / cm³. 3 .

[0011] The optimized medium-entropy alloy has a processing temperature of 700~1200℃, and a high-temperature weight gain of 4.39 g / m³ at 1000℃. 2 .h

[0012] The working principle and beneficial effects of this invention:

[0013] 1. In this invention, pure Al with a relative density of 2.7 g / cm³ is used. 3 Adding Al can significantly reduce the density of the alloy and give it good ductility and toughness; the density of pure Ti is approximately 4.5 g / cm³. 3 It is about half the density of iron, possesses high strength and high-temperature resistance, as well as good plasticity and toughness; metallic V is adjacent to Ti in the periodic table, and its density is approximately 5.96 g / cm³. 3 Adding vanadium (V) to an alloy can simultaneously improve both the material's strength and toughness; metallic Cr exceeding 8% at can improve the alloy's plasticity to some extent and can form a Cr2O3 oxide film, thereby enhancing the material's high-temperature oxidation resistance.

[0014] 2. The present invention mixes Al-Ti-V-Cr elements in a certain proportion to prepare a medium-entropy alloy with ultra-high strength, low density, high temperature resistance and excellent hot workability. Attached Figure Description

[0015] Figure 1 This invention provides a novel ultra-high strength lightweight Al-Ti-V-Cr medium-entropy alloy as-cast sample.

[0016] Figure 2 Scanning electron microscope (SEM) images of the as-cast specimen of the novel ultra-high strength lightweight Al-Ti-V-Cr medium-entropy alloy for this invention;

[0017] Figure 3 This is an EDS image of a cast sample of a novel ultra-high strength lightweight Al-Ti-V-Cr medium-entropy alloy, used in this invention.

[0018] Figure 4 The stress-strain curves of the novel ultra-high strength lightweight Al-Ti-V-Cr medium-entropy alloy sample under room temperature compression test are shown in the present invention. Detailed Implementation

[0019] The following detailed description illustrates the specific implementation methods:

[0020] The ultra-high strength lightweight Al-Ti-V-Cr medium-entropy alloy in this technical solution comprises, by mass percentage: Al: 24~28%; Ti: 45~50%; V: 10~14%; Cr: 10~14%. This medium-entropy alloy is composed of BCC phase and phase (such as...). Figure 2 The total content of impurity elements is ≤0.01%. The impurity elements are H, O, N, Fe, and Si. The material's uniformity is as follows: Figure 3 As shown.

[0021] The medium-entropy alloy has a room temperature strength >1.67 GPa, a hardness of 400~600 HV, and a density ≤4.3 g / cm³. 3 The processing temperature of the medium-entropy alloy is 700~1200℃, and the weight gain at 1000℃ is 4.39 g / m³. 2 .h

[0022] Example 1: An ultra-high strength lightweight Al-Ti-V-Cr medium-entropy alloy, comprising by mass percentage: Al: 26.36%; Ti: 48.16%; V: 12.44%; Cr: 12.92%; total impurity element content ≤0.01%, wherein the impurity elements are H, O, N, Fe and Si.

[0023] A medium-entropy alloy was prepared by smelting, and samples were taken to test its density, hardness, and compressive strength. The Al-Ti-V-Cr medium-entropy alloy in Example 1 tested to achieve a compressive strength of 1.672 GPa, a hardness of 492 HV, and a density of 4.31 g / cm³. 3 It achieves ultra-high strength and lightweight properties.

[0024] The high-temperature oxidation resistance of the alloy was tested. The results showed that the Al-Ti-V-Cr medium-entropy alloy in Example 1 exhibited a weight gain of 4.39 g / m³ after oxidation at 1000℃. 2 .h

[0025] Example 2: An ultra-high strength lightweight Al-Ti-V-Cr medium-entropy alloy, comprising by mass percentage: Al: 26.79%; Ti: 52.96%; V: 9.75%; Cr: 10.42%; total impurity element content ≤0.01%, wherein the impurity elements are H, O, N, Fe and Si.

[0026] A medium-entropy alloy was prepared by smelting, and samples were taken to test its density, hardness, and compressive strength. The Al-Ti-V-Cr medium-entropy alloy in Example 2 showed a compressive strength of 1.51 GPa, a hardness of 452 HV, and a density of 4.26 g / cm³. 3 It achieves ultra-high strength and lightweight properties.

[0027] The high-temperature oxidation resistance of the alloy was tested. The results showed that the Al-Ti-V-Cr medium-entropy alloy in Example 2 exhibited a weight gain of 2.28 g / m³ after oxidation at 1000℃. 2 .h

[0028] Therefore, based on the test analysis of Examples 1 and 2, it can be concluded that a novel ultra-high strength lightweight medium-entropy alloy can be prepared by mixing Al, Ti, V, and Cr in a certain proportion. This alloy exhibits a room temperature strength exceeding 1.67 GPa, a hardness of 400-600 HV, and a weight gain of 4.39 g / m³ at 1000℃. 2 .h, density ≤4.3g / cm³ 3 It achieves ultra-high strength and lightweight properties.

[0029] The material's room temperature compression set is close to 20%. Figure 4 It has good high-temperature hot working plastic forming properties and has broad application prospects in the manufacture of high-performance, lightweight structural components in aerospace and other fields.

[0030] For those skilled in the art, numerous modifications and improvements can be made without departing from the inventive concept of this invention. These modifications and improvements should also be considered within the scope of protection of this invention, and will not affect the effectiveness of the invention or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A high-strength, lightweight Al-Ti-V-Cr medium-entropy alloy, characterized in that, The mass percentage comprises: Al: 24-28%; Ti: 45-50%; V: 10-14%; Cr: 10-14%; total content of impurity elements is less than or equal to 0.01%; the medium-entropy alloy has a room temperature strength greater than 1.67 GPa, a hardness of 400-600 HV, and a density of less than or equal to 4.3 g / cm 3 ; the medium-entropy alloy has a processing temperature of 700-1200 DEG C, and a 1000 DEG C high-temperature weight gain of 4.39 g / m 2 .h.

2. The ultra-high strength lightweight Al-Ti-V-Cr medium-entropy alloy according to claim 1, characterized in that, The content by mass percentage includes: Al: 26~28%; Ti: 46~48%; V: 10~14%; Cr: 10~14%; and the total content of impurity elements is ≤0.01%.

3. The ultra-high strength lightweight Al-Ti-V-Cr medium-entropy alloy according to claim 1, characterized in that, The content by mass percentage includes: Al: 24~28%; Ti: 45~50%; V: 12~13%; Cr: 12~13%; and the total content of impurity elements is ≤0.01%.

4. The ultra-high strength lightweight Al-Ti-V-Cr medium-entropy alloy according to claim 3, characterized in that, The impurity elements are H, O, N, Fe, and Si.

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