Low-cost, high-strength and high-plasticity metastable beta titanium alloy and preparation method thereof

Abstract

The invention discloses a low-cost, high-strength and high-plasticity metastable beta titanium alloy and a preparation method thereof. The titanium alloy comprises the following components in percentage by weight: 3-7% of Fe, 4-7.75% of Al, 3-5% of V, O not more than 0.2%, C not more than 0.08%, N not more than 0.05%, and the balance of titanium and inevitable impurities. The preparation method comprises the following steps: sponge titanium, an Al-V intermediate alloy, pure Al and pure Fe are weighed according to ratios; the raw materials are mixed to press as an electrode; a Ti-Al-Fe-V alloy cast blank is prepared by secondary smelting; the cogging and the primary forging are performed to obtain a large-scale forging; the secondary forging is performed to obtain a larger-size rod; the ternary forging is performed to obtain a small-size rod; the solid-solution treatment and the air cooling are performed; and then, the aging treatment and the air cooling are performed to obtain the low-cost, high-strength and high-plasticity metastable beta titanium alloy. The titanium alloy contains higher-content beta elements and stable elements Fe, and has such advantages as low cost, high strength and high plasticity.

Description

Technical field [0001] The invention belongs to the technical field of metal material preparation and processing, and particularly relates to a low-cost, high-strength, high-plasticity metastable beta titanium alloy and a preparation method thereof. Background technique [0002] Titanium alloy has the characteristics of low density, high specific strength, high specific rigidity, corrosion resistance, good high and low temperature performance and biological compatibility. Therefore, as an ideal structural material and functional material, it is widely used in aerospace, ship manufacturing, petrochemical industry , Marine engineering, biomedicine and architectural decoration and other fields, and have obtained good economic and social benefits. [0003] Commercial high-strength near-beta titanium alloys currently widely used include Ti-1023, BT22, and VST5553. These alloys either use a larger content of high-cost Mo%+V%, which has a higher cost; or there is no obvious price. Advant...

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Problems solved by technology

[0003] Currently widely used commercial high-strength near-β titanium alloys include Ti-1023, BT22, and VST5553. These alloys either use a large amount of high-cost Mo%+V%, which has a high cost; or has no obvious price Advantages and low alloy strength

For example, the patent number is 201610934241.2, "a low-cost near-β-type high-strength titanium alloy containing Fe and its preparation method", and the weight percentage of alloying elements contained in the titanium alloy is: Al: 2.5%-5.5%; Fe: 0.5- 2.2%; Mo: 4.7%-5.7%; Cr: 3.5%-4.5%; Zr: 1.5%-3.5%; the cheap element Fe content is low, while the expensive element Mo content is high, and because Mo is a high melting point metal , which undoubtedly increases the cost of alloying elements and smelting costs

For example, the patent number is 201410821718, "a low-cost high-strength high-toughness titanium alloy and its preparation method." The weight percentage composition of the alloy is: Al: 2.5-3.5%, Fe: 0.85-2.35%, V: 3.0-8.0%, Cr: 1.0-5.0%, O<0.2%, and the balance is Ti. Not only is the low-cost element Fe content in the alloy low, but the high-cost alloy element is relatively high, and its alloy strength is only 1106-1289MPa; another example is the patent number 201610985168.1 , the name is "a low-cost titanium alloy and its preparation method" and the patent number is 201610130527.5, the name is "a low-cost titanium alloy containing Fe and Mn elements", and the Fe content of the two alloys is 0.5-5wt.% respectively and 4-6wt.%, the alloy strengths are 750MPa-850MPa and 1203MPa-1233Mpa respectively, which has a significant gap compared with high-strength alloys

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