Different strain-rate dependent compressive properties and work-hardening capacities of 50vol% TiC_x/Al and TiB_2/Al composites

摘要

Compression tests of the 50vol% TiC_x/Al and the 50vol% TiB_2/Al composites have been performed in the strain rate range from 1 ×10~4s~(-1) to 1×10~(-1)s~(-1), and the effect of strain rate on the compressive behavior and the work-hardening capacity (H_c) of them have been investigated. The yield strength (σ_(true)~y) and the H-c of both the composites are strain rate sensitive, while the ductility is insensitive to the strain rate. The ultimate compressive strength (σ_(true)~(UCS)) of the TiB_2/Al composites is not significantly influenced by the strain rate, while that of the TiCx/A1 composite increases from 615 MPa to 826 MPa with the strain rate increasing. Under various strain rates, the σ_(true)~(UCS)of the TiB_2/Al composite is significantly better than that of the TiC_x/Al composite, while its ductility and H_c are lower than that of the TiC_x/Al composite. At the strain rate of 1 x 10~(-4) s~(-1), the σ_(true)~(UCS) of the TiB_2/Al composite and the TiC_x/Al composite are 1071 MPa and 615 MPa, respectively; while the H_c of them are 0.87 and 0.99, respectively.