Mo coating SiC fiber-reinforced TiAl-based composite material and preparation method thereof

Abstract

The invention provides a Mo coating SiC fiber-reinforced TiAl-based composite material and a preparation method thereof. The preparation method comprises the following steps of, first preparing a layer of C coating with the thickness of 2-4 micrometers on the SiC fiber surface through a chemical vapor deposition method; and then preparing a layer of Mo metal coating with the thickness is 0.5-2 micrometers on the SiC fiber surface with the C coating through uniform deposition; and finally preparing the Mo coating SiC fiber-reinforced TiAl-based composite material through a foil-fiber-foil method and a fiber coating method. According to the Mo coating SiC fiber-reinforced TiAl-based composite material, the interface reaction between a fiber and a matrix as well as the consumption speed of the C coating of the fiber at a high temperature are effectively reduced, and the Mo coating has excellent thermal stability, does not get involved in an interface reaction and does not diffuse, so that the thermal residual stress at the interface of the composite material can be effectively relieved.

Description

technical field [0001] The invention relates to a magnetron sputtering physical deposition technology and a preparation technology of a metal-based composite material, which can improve the interfacial performance of the composite material by using a fiber coating. Background technique [0002] Compared with traditional titanium-based composites, SiC fiber-reinforced TiAl-based composites have higher service temperature and better creep resistance, which can further meet the material performance requirements of aerospace components, so SiC fiber-reinforced TiAl-based composites It has received attention from all over the world. [0003] However, during high-temperature preparation and high-temperature service, interfacial reactions will occur between the TiAl matrix and SiC fibers, and compared with traditional titanium alloys, the TiAl-based alloy matrix with poor plasticity is more prone to cracking under the action of thermal residual stress, thus worsen the mechanical p...

AI Technical Summary

Problems solved by technology

[0004] At present, the widely used interface modification coating technology is to coat a layer of C coating on the surface of SiC fibers. The results show that C coating can effectively reduce the damage of fibers during the preparation process, but this coating hinders the interface reaction. The capacity of the TiAl alloy is limited, and it is prone to serious loss at high temperature. In addition, the C element will diffuse into the TiAl alloy matrix in a large amount at high temperature, which will further embrittle the matrix structure and cause the overall performance of the composite material to decline.

Harbin Institute of Technology invented a TiN-coated SiC fiber-reinforced Ti-based composite material. Studies have shown that the coating not only effectively slows down the reaction between the fiber and the matrix but also obtains good interfacial bonding strength (patent application number 201110003731.8), but TiN coating is a brittle material, which is easy to crack first under the action of mechanical load and thermal residual stress. In addition, literature research shows that the fiber strength is easy to decrease during the coating preparation process.

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