Machining process modeling of green alumina ceramics in orthogonal cutting and fragmentation process

Abstract

Theories on mechanical model and discrete element model (DEM) of machining green ceramics are sought to reveal the material removal mechanisms and cutting force. Theoretical models are based on brittle fracture mechanics, equilibrium, and minimum chipping energy principle etc., and in the model, friction on flank face of tools and material’s rebound deformation are considered. DEM is established based on macro-mechanical properties of green alumina ceramics. Orthogonal cutting experiments were conducted to validate the mechanical model and DEM. Results show that the material removal mechanism of green alumina ceramics contains both crushing failure and chipping failure. The experiments validate good agreement with mechanical model and DEM in regard to chip formation and tangential cutting force. Friction force during machining green alumina ceramics contributes more than 50% of tangential cutting force. It is the reason that there exists more serious flank wear of cutting tool.