Mechanical properties and thermal shock resistance of TiB₂‒B₄C composite ceramic tool materials at microscopic scale

A finite model incorporating microstructure was developed to investigate the thermal shock resistance of TiB 2 ‒B 4 C composite ceramic cutting tool materials. Numerical simulations were conducted to analyze changes in the transient temperature field and thermal stress field during the thermal shock process. TiB 2 ‒B 4 C composite ceramic tool materials were fabricated using discharge plasma sintering technology. With different B 4 C contents, different sintering temperatures and holding times as study variables, optimization of the sintering process parameters and ceramic material components was achieved through testing the mechanical and microscopic morphology of the ceramics. Thermal shock water quenching experiments were performed, and the strength‐decay method was employed to assess the thermal shock resistance of TiB 2 ‒B 4 C ceramics. The findings indicate that the optimal sintering conditions are temperature of 1700°C and holding time of 5 min. The TiB 2 ‒B 4 C ceramic material containing 20 vol% B 4 C exhibits superior comprehensive mechanical properties and thermal shock resistance, and its relative density, fracture toughness, hardness, and flexural strength were 99.3%, 6.8 MPa m 1/2 , 22.8 GPa, and 598 MPa, respectively. The critical thermal shock temperature difference falls within the range of 400°C‒500°C.