Preparation of SiCp/Cu composites by Ti-activated pressureless infiltration
(State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering,
University of Science and Technology Beijing, Beijing 100083, China)
University of Science and Technology Beijing, Beijing 100083, China)
Abstract: Sessile drop technique was used to investigate the influence of Ti on the wetting behaviour of copper alloy on SiC substrate. A low contact angle of 15˚ for Cu alloy on SiC substrate is obtained at the temperature of 1 100 ℃. The interfacial energy is lowered by the segregation of Ti and the formation of reaction product TiC, resulting in the significant enhancement of wettability. Ti is found to almost completely segregate to Cu/SiC interface. This agrees well with a coverage of 99.8%Ti at the Cu/SiC interface predicted from a simple model based on Gibbs adsorption isotherm. SiCp/Cu composites are produced by pressureless infiltration of copper alloy into Ti-activated SiC preform. The volume fraction of SiC reaches 57%. The densification achieves 97.5%. The bending strength varies from 150 MPa to 250 MPa and increases with decreasing particle size.
Key words: SiC/Cu composites; metal matrix composites; pressureless infiltration; wettability; mechanical property