INTERFACIAL MICRO STRUCTURE AND DISTRIBU- TIONS OF NANOHARDNESS AND MODULUS NEAR INTERFACE OF TiCx/NiAl COMPOSITES
HUA Wenshen, WU XingfangDepartment of Materials Physics, University of Science and Technology Beijing, Beijing 100083LU Hua, SHEN DianhongState Key Laboratory for Surface Physics, Institute of Physics, The Chinese Academy of Sciences, Beijing 100080
he morphologies and the elements diffusion status of TiCx/Ni3Al composites with four C/Ti ratios fabricated by pressureless melt-infiltration processing were studied using SEM and EDS. The TiCx particle size decreased with the C/Ti ratio increasing from 0.6 to 0.9. The strong diffusion of Ti from the ceramic phase to the intermetallic resulted in enhancement of the interfacial strength owing to the atomic bonding at the interface. The mechanical properties at the interfaces of TiCx/NisAl composites were investigated using the nanoindentation technique. It was found that the nanohardness and the elastic modulus from the phase TiCx to the Ni3Al are a gradient distribution. As x increased from 0.6 to 0.9, elastic modulus at the interface decreased and the interfacial nanohardness reached its higher value at x equal to 0.7.