Wear Resistance of TiB2-TiC Solidified Ceramics Using for Cutting Tools Fabricated through Combustion Synthesis in the High-Gravity Field

摘要

TiB2-TiC solidified ceramics were fabricated by taking combustion synthesis with the blends of(B4C+Ti)powders and(CrO3+Al)thermite in the high-gravity field of 300 g.XRD,FESEM and EDAX results showed that the composites mainly were consisted of fine plate-like TiB2,irregular TiC and(Cr,Ti)3B2 solids and A1203 inclusion particles.The introduction of high-gravity field was thought to bring about pure Ti-Cr-B-C liquid.Rapid solidification was a key factor for the achievement of fine-grained microstructure,which in turn was responsible for the improved wear properties of the composites.Vickers hardness,fracture toughnessandmaximum wear rate of the composites were measured 20.8GPa,13.4MPa-m0’5 and 2.5xlO”7g-(N-m)”‘,respectively.The excellent wear resistance of the composites was considered resulting from the contribution of the high-toughness,high-hardness,fine-grained TiB2 plate-like primary phases.