Effects of SiC on the Microstructure, Densification, Hardness and Wear Performance of TiB2 Ceramic Matrix Composite Consolidated Via Spark Plasma Sintering

Abstract

Monolithic TiB 2 are known to have a good combination of densi cation and hardness which are sometimes useful but limited in application. However, their usage in service at elevated temperatures such as in power thermal plants, cutting tools, tribological purposes (cutting tools, mechanical seals, blast nozzles, and wheel dressing tools), etc leads to catastrophic failure. Hence, the introduction of sintering additives in the TiB 2 matrix has a high in uence on the improvement of its sinterability, and properties (fracture toughness, wear resistance etc.,) of the resulting composite needed to meets the requirement for various industrial applications. In this study, the in uence of SiC as sintering additives on the microstructure, densi cation, hardness and wear performance of TiB 2 ceramic was observed. Hence, TiB 2, TiB 2 -10wt%SiC and TiB 2 -20wt%SiC were sintered at 1850 o C for 10 minutes under 50 MPa. The impacts of SiC on the TiB 2 were observed to improve the microstructure correspondingly improving densi cation and mechanical properties, most especially with the composites with 20wt% SiC. Combined excellent densi cation, hardness and fracture toughness of 99.5%, 25.5 GPa, 4.5 MPa.m 1/2 were achieved respectively for TiB 2 -20wt%SiC. Diverse in-situ phase and microstructural alterations were detected in the sintered composites, and it was discovered that the in-situ phase of TiC serves as the contributing factor to the enhanced features of the composites. Moreover, the coe cient of friction and wear performance outcomes of the synthesized composites described a decrease in the coe cient with an enhanced wear resistance via the increasing SiC particulate, although the application of the load from 10 N-20 N increased the wear rates.