Elaboration and mechanical characterisation of a metal matrix composite: NiAl-SiCp and NiAl-ZrO_2p.

摘要

Strength and fracture toughness of three NiAl-based materials reinforced with ceramic particles were examined and correlated to toughening mechanisms. Toughness of NiAl was lowered by addition of SiC particles because of the high thermal expansion mismatch and the weakness of the intermetallic-ceramic interface. Concerning NiAl-ZrO_2 composite, results show that an improvement in flexural strength and Fracture toughness, i.e., 735 Mpa and 11,3 Mpa/m can be reached by incorporating 15/100vol of ZrO_2. The mechanism of toughening is considered to be a stress induced transformation of Metastable tetragonal zirconia particles.