A kind of nearly isothermal forging method of tial alloy

Abstract

The invention discloses a TiAl alloy near-isothermal forging method, which comprises: putting a pretreated ingot into a sheath, sealing the end cap of the sheath and the sheath; putting the ingot put into the sheath into a heat treatment Heating in the furnace to 1270-1320°C at a uniform speed, and keeping it warm for 1-2h after reaching the target temperature; raising the temperature of the hydraulic press head to 600°C; completing at least four passes of forging and heat preservation; among them, before the next pass of forging compression, The ingots are rotated 90° along the axial direction, and the heat preservation time after the first and second forging passes is 1.5 hours, and the heat preservation time after the third and subsequent passes is 1.5-2.5 hours. h; After the last return to the furnace for heat preservation, cool down to 900°C with the furnace, take out, cool, and remove the jacket to obtain a forged billet. The invention enables the forging process to be in a nearly isothermal environment, can be operated on an ordinary forging machine, reduces the cracking tendency of the forging billet, lowers the forging cost, and can be better used for the forging of α-solidified TiAl alloy.

Description

technical field [0001] The application belongs to the technical field of intermetallic compound forging, and in particular relates to a TiAl alloy near-isothermal forging method. Background technique [0002] As a new type of light-weight, high-temperature-resistant, high-specific-strength structural material, TiAl alloy can serve in the temperature range of 700-900 °C, and has broad application prospects in the aerospace field. The use of TiAl alloys instead of traditional high-temperature alloys and high-temperature titanium alloys to prepare high-performance hot-end components can not only improve the thermal efficiency of the engine, but also achieve substantial structural weight reduction. Therefore, TiAl alloys have become a research hotspot in recent years. [0003] At present, Ti-48Al-2Cr-2Nb alloy is the most widely used TiAl alloy material. For such α-solidified TiAl alloys, casting is a commonly used hot forming method. However, the casting process often has def...

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Problems solved by technology

[0008] In order to solve the problem of lack of forging process suitable for α-solidified TiAl alloy and uneven structure during unidirectional forging in the existing research, and to break through the limitation of ingot height-to-diameter ratio and isothermal forging machine, this application proposes a TiAl alloy close to Isothermal forging methods, including:

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