TiAl alloy near-isothermal forging method

Abstract

The invention discloses a TiAl alloy near-isothermal forging method. The method comprises the following steps that a pretreated cast ingot is put into a sheath, and a sheath end cover and the sheath is sealed; the cast ingot loaded into the sheath is put into a heat treatment furnace, heating is conducted to 1270 DEG C-1320 DEG C, and heat preservation is conducted for 1-2h after the target temperature is reached; a press head of a hydraulic press is heated to 600 DEG C; at least four passes of forging and heat preservation are completed; and the cast ingot is rotated by 90 degrees in an axialdirection before each next pass of forging compression, furnace return heat preservation time after the first pass forging and the second pass forging is 1.5h, furnace return heat preservation time after the third pass forging and following pass forging is 1.5h-2.5h, after furnace return heat preservation of the last pass is finished, furnace cooling is conducted to 900 DEG C, and taking-out, cooling, and sheath removing are conducted to obtain a forged blank. According to the method, a forging process is in a near- isothermal environment, cracking tendency of the forging blank is reduced while operation can be carried out on a common forging machine, the forging cost is reduced, and the method can be better used for forging alpha solidification 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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