SiC fiber-reinforced TiAl-based composite with Mo coating and preparation method of SiC fiber-reinforced TiAl-based composite

Abstract

The invention provides an SiC fiber-reinforced TiAl-based composite with an Mo coating and a preparation method of the SiC fiber-reinforced TiAl-based composite. The preparation method comprises the steps of firstly, preparing a layer of C coating with the thickness of 2-4[mu]m on the surface of SiC fiber by using a chemical vapor deposition process; then, uniformly depositing an Mo metal coating with the thickness of 0.5-2[mu]m on the surface of the SiC fiber with the C coating by using a magnetron sputtering deposition process; and finally, preparing the SiC fiber-reinforced TiAl-based composite with the Mo coating by using a foil-fiber-foil process or a fiber coating process. The interface reaction speed of the fiber and a matrix and the consumption speed of the C coating of the fiber under a high-temperature condition are effectively reduced, and the Mo coating is excellent in thermal stability, does not participate in the interface reaction, is not diffused and can be used for effectively relieving the thermal residual stress at the interface of the composite.

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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