COMBUSTION SYNTHESIS AND TWO-TIME DENSIFICATION OF TiB₂-Cu COMPOSITES

TiB₂-40Cu ceramic-metal composite with the relative density of about 90% was prepared by combustion synthesis. The elastic-plastic deformation behavior of high temperature compression was studied in order to prove that TiB₂-40Cu has certain plasticity in high temperature. On the basis of high temperature compression, the two-time hot pressing sintering was conducted at 1050℃,1090℃ and 1150℃ . The deformation behavior and the variation of microstructure and mechanical properties were investigated in detail. The results show that the relative density and the flexural strength increase greatly after two-time hot pressing. The relative density reaches 605.5 MPa and the flexural strength reaches 96% at 1090℃,and increases 12% and 6% respectively. Macroscopical and microcosmic densification mechanisms were studied. The results show that densification processes are affected by multiplicate mechanisms together.