Progressive flank wear and machining performance of silver toughened alumina cutting tool inserts

Alumina-based composites with different amounts of silver as second phase have been fabricated using conventional powder metallurgical route and their microstructure, density, thermal conductivity, hardness and fracture toughness have been studied. Cutting tool inserts fabricated from these composites were subjected to dry turning operations on 0.45% C steel bars under wide range of cutting parameters. Performance evaluation of the silver toughened alumina inserts was done on the basis of progressive flank wear, and was supplemented by cutting force, surface roughness and chip morphology analyses. Within the investigated range, abrasion and plastic deformation are considered to be the active wear mechanisms for the developed inserts. A comparative examination of the developed composites with those of commercial zirconia toughened alumina (ZTA) inserts indicates that the developed composites have high potential for commercial exploitation. (c) 2006 Published by Elsevier B.V.