Abstract:SiCf/Ti-6Al-4V composites prepared by laser cladding have short reaction time and diffusion time. The interfacial properties and micromechanical properties of SiCf/Ti-6Al-4V composites under different vacuum thermal exposure conditions were studied. By means of scanning electron microscope (SEM), energy dispersive spectrometer (EDS), transmission electron microscope (TEM) and nanoindentation instrument, the thickness of the reaction layer, chemical composition at the interface and micromechanical properties at different temperatures and times after vacuum thermal exposure were characterized. It is found that the interfacial reaction between reinforcer, C coating and matrix occurs in the process of laser cladding laminated composites, and the main interfacial reaction product is TiC. Short time vacuum thermal exposure increases the thickness of the interfacial reaction layer and decreases the thickness of the C coating. With the extension of thermal exposure time, the growth of the reaction layer conforms to a parabolic law. The kinetic parameters of the reaction are frequency factor k0 =6.005×10-3 m.s-1/2, and activation energy Q=143.13 kJ.mol-1. The hardness and elastic modulus of fiber, C coating, substrate and interfacial reaction layer do not change obviously after 900℃ short-time vacuum thermal exposure, indicating that the material has good short-time thermal stability at 900℃ and below.