Alumina-based nanocomposite ceramic cutting tool materials toughened by graphene nanoplates

Abstract

Graphene nanoplates(GNPs), as toughening phase, toughened alumina-based nanocomposites ceramic cutting tool materials were fabricated by hot-pressing technology. The dispersing experiment of the GNPs was performed. The effects of different GNPs contents on the fracture toughness, flexural strength and hardness of the as-sintered ceramic cutting tool materials were investigated. The microstructure and morphology of GNPs were also observed. The results show that polyvinyl pyrrolidone(PVP) is the optimized dispersant of GNPs. When PVP addition is the 60%(mass fraction) of GNPs, the GNPs dispersion effect is the best. When GNPs addition is 0.75%(volume fraction), the fracture toughness and flexural strength of the cutting tool material reach up to 7.1MPa·m1/2 and 663MPa, which increase by 31% and 15% compared with that without GNPs addition cutting tool material. The crimped GNPs disperse well in the matrix material. The main toughening mechanisms include GNPs rupture, GNPs pull-out and cracks defection. Comparing with no GNPs addition cutting tool material, GNPs toughened cutting tool material shows lower main cutting force, cutting temperature and rake friction coefficient, and better wear resistance.

Keywords

• graphene nanoplate
• toughening and strengthening
• ceramic cutting tool
• mechanical property
• cutting performance