Investigation of the wear characteristics of microcrystal alumina abrasive wheels during the ultrasonic vibration-assisted grinding of PTMCs

Abstract

As newly developed metal matrix composites, particulate-reinforced titanium matrix composites (PTMCs) have been eliciting increasing attention in the fields of aviation and aerospace due to their superior temperature durability and mechanical properties. Grinding is an important method for achieving high-efficiency and precision machining of PTMCs. However, the service life of abrasive wheels is severely affected under the action of alternating loads due to the existence of hard–brittle TiC particle reinforcements embedded into PTMCs materials. Ultrasonic vibration-assisted grinding (UVAG) is widely used at present for machining difficult-to-cut materials, particularly for improving the wear performance of abrasive wheels. In this work, comparative experiments on the conventional grinding (CG) and UVAG of PTMCs were conducted to investigate the wear properties of microcrystal alumina abrasive wheels. Moreover, characterisation of tool wear morphologies was performed. On the basis of the standard deviation of the Gaussian distribution of workpiece profile, active cutting edge density was evaluated. Lastly, grinding force and machined surface quality were analysed in detail. Results showed that CG caused severe adhesion and macrofractures, whereas UVAG produced slight adhesion and microfractures. UVAG also achieved lower grinding force and better surface quality than CG. Furthermore, UVAG provided a longer steady tool wear region than that in CG because ultrasonic vibration can enhance the self-sharpening characteristics of microcrystal alumina abrasive wheels during grinding.