Indexed on: 29 Jan '16Published on: 29 Jan '16Published in: The International Journal of Advanced Manufacturing Technology
TiB2-10wt%SiC ceramic cutting tools were fabricated by the reactive hot pressing (RHP) technique. The mechanical properties and microstructure of the materials at room temperature were investigated. The flexural strength, fracture toughness, and hardness were 705 MPa, 6.6 MPa m1/2, and 22.5 GPa, respectively. The improved fracture toughness was ascribed to the mixed mode of intergranular fracture and transgranular fracture. The cutting performance including the tool life and surface roughness, as well as the failure mechanisms of the ceramic cutting tools when continuously wet-turning Invar36 alloy, was studied. Orthogonal test and range analysis were employed to determine the optimal cutting parameters. The optimal cutting speed, feed rate, and depth of cut were 140 m/min, 0.1 mm/rev, and 0.4 mm, respectively. The wear resistance of the TiB2-SiC ceramic cutting tool was better than that of the Al2O3-based ceramic cutting tool reinforced by TiC particles. The wear mechanisms were abrasive wear, diffusion wear, and oxidation wear. The tool life reliability when continuously wet-turning Invar36 alloy using the optimized cutting parameters was investigated. The distribution of the tool life obeyed the log-normal distribution, and the coefficient of variation was 0.085, indicating that the ceramic cutting tools had a high reliability. The study on the cutting performance and tool life reliability is useful for improving the machining efficiency, decreasing the rejection rate, and determining the tool replacement interval.