Surface Characteristics and Scratch Resistance of Si-based Ceramics Subjected to Ultrasonic Nanocrystalline Surface Modification Treatment at High Temperatures

In the past, a couple of drawbacks have always prevented the widespread use of sintered silicon carbide (SiC) and silicon nitride (Si₃N₄) ceramics from wear reducing applications: relatively high costs and inadequate availability of a complicated sintering process, and the brittleness of ceramic materials. The surface characterizations and scratch resistance of SiC ceramic after ultrasonic nanocrystalline surface modification (UNSM) treatment at high temperatures was investigated. The effects of applied temperature on the hardness, compressive residual stress, microstructure and scratch behavior were particularly analyzed and discussed. The objective of this study is to get some insight into the UNSM treatment temperature effects on surface properties of Si-based ceramics and to develop a cost effective simple process that may be used to improve the strength and fracture toughness of Si-based ceramics for various applications.