A kind of preparation method of γ-tial base alloy bar

Abstract

The invention discloses a preparation method of a gamma-TiAl-based alloy bar. The preparation method comprises the following steps: (I) preparing a gamma-TiAl alloy ingot through a vacuum melting method; (II) manufacturing a jacket, wherein the jacket comprises a jacket cylinder and jacket covers, the jacket covers are used for sealing the two end openings of the jacket cylinder, and each jacket cover is provided with a ventilating hole; (III) thermally treating the cylinder body, subsequently coating the inner wall of the cylinder body with an oxidation-resistant coating, afterwards putting the TiAl alloy ingot in the cylinder body and finally welding each jacket cover on the corresponding open end of the cylinder body; (IV) externally coating the oxidation-resistant coating, carrying out thermal treatment, subsequently extruding in an extruder to obtain the bar, and straightening the bar by letting the bar directly pass through a straightening tube; and (V) removing the jacket on the outer surface and carrying out homogenizing annealing treatment to obtain the gamma-TiAl-based alloy bar. The problem that a TiAl intermetallic compound is relatively large in brittleness and easy to oxidize in a hot working process can be solved through the preparation method disclosed by the invention, and the prepared gamma-TiAl-based alloy bar is uniform in microstructure and high in mechanical property.

Description

technical field [0001] The invention belongs to the technical field of intermetallic compounds, and in particular relates to a method for preparing gamma-TiAl-based alloy rods. Background technique [0002] γ-TiAl intermetallic compound has the characteristics of high specific strength, specific modulus, good oxidation resistance, creep resistance, excellent high temperature strength, stiffness and low density, and has become an important candidate material for high temperature structural materials on aerospace vehicles one. However, the intrinsic brittleness and low room temperature plasticity of γ-TiAl-based alloys bring great difficulties to its processing and forming, and also restrict its wide application in structural materials. The quality of TiAl alloy preparation will be related to the comprehensive mechanical properties of the alloy, affect the development process and speed of the aviation industry, and is also a prerequisite for the industrial application of the ...

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Problems solved by technology

At present, many scholars have researched different sheath design schemes, such as placing or pasting titanium plates or precious metal plates on the inner lining of the sheath, or putting in a glass fiber insulation layer, or vacuuming the space between the sheath and the blank, etc. These technological processes Complicated, poor operability and high cost, or only limited to the processing of small samples, the application prospects are limited

At present, the domestic TiAl alloy mostly adopts a multi-layer sheath structure with an increased isolation layer. For example, a fiber layer is added to the outer sheath to prevent temperature drop, and the fiber layer is mostly made by hand, which has poor stability, and the fiber material is harmful to the human body. Hazardous; or some add pure titanium plates for insulation, the process is complicated and the cost is high

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