Simulation testing machine Gleeble1500D is employed to carry out tixotropic isothermal compression experiments for semi-solid n-SiCP/AZ61 composites. The effects of different factors (strain rate, deformation temperature and reinforcing phase mass fraction) on true stress-strain curves are analyzed. And semi-solid tixotropic compression deformation mechanism and microstructure after tixotropic compression of n-SiCP/AZ61 composites are discussed. The results show that the true stress decreases with the decrease of strain rate, and the peak stress value of true stress-strain curve reduces markedly with the increase of strain temperature. And the deformation resistance of n-SiCP/AZ61 composites under semi-solid tixotropic compression deformation process increases with the increase of nano-SiC particles. According to stress-strain curves, the deformation process can be divided into three stages, i.e. "rising", "falling" and "stable". Their main deformation mechanisms are respectively slip between solid particles and plastic deformation of solid particles; mixing flow of liquid-solid particles, slip between solid particles and plastic deformation of solid particles; slip between solid particles and plastic deformation of solid particles. © 2010 Journal of Mechanical Engineering.
