Mechanical properties of low temperature synthesized dense and fine-grained Cr2AlC ceramics

Mechanically activated hot-pressing technology was used to synthesize a fine crystalline Cr2AlC ceramic at relatively low temperatures A mixture of Cr Al and C powders with a molar ratio of 2 1 2 1 was mechanically alloyed for 3 h and then subjected to hot pressing at 30 MPa and different temperatures for 1 h in Ar atmosphere The results show that a dense Cr2AlC ceramic with a grain size of about 2 mu m can be synthesized at a relatively low temperature of 1100 degrees C The synthesized fine-grained Cr2AlC has a high density of 99% which is higher than the 95% density for the coarse-grained Cr2AlC (grain size of about 35 mu m) as synthesized by hot pressing unmilled Cr, Al and C The flexural strength fracture toughness and Vickers hardness of the fine-grained Cr2AlC were determined and compared with the values for the coarse grained Cr2AlC (c) 2010 Elsevier Ltd All rights reserved