Ti2AlNb alloy and preparation method of Ti2AlNb alloy bar

Abstract

The invention relates to Ti2AlNb alloy and a preparation method of a Ti2AlNb alloy bar. The alloy comprises the following chemical components, in atomic percentage, of 22%-25% of Al, 20%-23% of Nb, 1%-8% of (Zr+Hf+W+Mo+Ta), greater than or equal to 0.5% of W, greater than or equal to 0.5% of Zr+Hf, and the balance Ti and inevitable impurities. A B2 single-phase region relatively-low-temperature upsetting and extrusion stretching composite process is adopted for ingot cogging, and a process of upsetting-stretching forging and stretching forming forging in two phase regions of (alpha2+B2) is further adopted to prepare the bar with the required specification. The provided Ti2AlNb alloy has good oxidation resistance, the tensile strength at 700 DEG C is 800 MPa or above, and the creep propertyat 700 DEG C is improved by 50%. The invention further provides a bar preparation method suitable for the Ti2AlNb alloy.

Description

technical field [0001] The present invention is a kind of Ti 2 The invention discloses a method for preparing AlNb alloy and rods thereof, belonging to the technical field of Ti-Al series intermetallic compounds. Background technique [0002] Compared with traditional high-temperature titanium alloys, Ti-Al alloys have the characteristics of low density, high specific strength, and good oxidation resistance. Ti 2 AlNb alloy is an important category of Ti-Al alloys, currently Ti 2 AlNb alloys gradually develop from Ti-Al-Nb ternary system to multi-component alloying, and the representative ternary Ti 2 AlNb alloys include Ti-23Al-24Nb, Ti-22Al-25Nb and Ti-22Al-27Nb, etc. Multi-alloyed Ti 2 AlNb alloys include Ti-22Al-20Nb-7Ta, Ti-22Al-24Nb-0.5Mo, Ti-22Al-23Nb-1Mo-1Zr, Ti-22Al-20Nb-2W, etc. Ti of V 2 AlNb alloys are also under development. The addition of V element is beneficial to the process plasticity of the alloy, but the effect on the high-temperature durable creep ...

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Problems solved by technology

Ti 2 AlNb alloy is an important category of Ti-Al alloys, currently Ti 2 AlNb alloys gradually develop from Ti-Al-Nb ternary system to multi-component alloying, and the representative ternary Ti 2 AlNb alloys include Ti-23Al-24Nb, Ti-22Al-25Nb and Ti-22Al-27Nb, etc. Multi-alloyed Ti 2 AlNb alloys include Ti-22Al-20Nb-7Ta, Ti-22Al-24Nb-0.5Mo, Ti-22Al-23Nb-1Mo-1Zr, Ti-22Al-20Nb-2W, etc. Ti of V 2 AlNb alloys are also under development. The addition of V elements is beneficial to the process plasticity of the alloys, but the effect on the high-temperature durable creep properties remains to be investigated.

Existing Ti 2 The short board of AlNb alloy comes from two aspects: one is the oxidation resistance, Ti 2 The Nb content of AlNb alloys is generally above 20%, which falls in the area where the oxidation resistance is unfavorable; the second is that the creep performance is low, due to the high alloying characteristics, the flaky and dual-state Ti 2 The matrix B2 transformation structure of AlNb alloy is too small, which is not conducive to creep performance

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