The Performance Evalution of Ceramic And Carbide Cutting Tools In Machining of Austemepered Ductile Irons

Abstract

The aim of this research is to compare TiN (PVD) coated Al2O3+Ti[C,N] mixed alumina-based (KY4400) ceramic and CVD coated carbide TiC+AI2O3+TiN (ISO P25) cutting tools in turning austempered ductile irons. Ductile cast iron samples were austenitized at 927°C and subsequently austempered for 1 hour at 400°C. The hardness of the workpiece material was measured and found to be 43.5 HRC. In the present work a series of tests were conducted in order to evaluate the tool performances by adopting tool life. In all experiments cutting forces, flank wear and surface roughness values were measured throughout the tool life. No cutting fluid was used during the turning operations. Study of the tool life and failure modes shows that tool life was determined by the flank wear and surface roughness generated on the workpiece. The main conclusion is that tool life of ceramic insert was longer than the coated carbide insert although much higher cutting speeds were used.

Keywords

• ceramics
• wear
• tool life
• cutting force
• ductile iron