Improvement of PVD coated inserts cutting performance, through appropriatemechanical treatments of substrate and coating surface

The wear behavior of coated cemented carbides (HM) inserts with various sub strate and coating surface mechanical treatments were investigated experime ntally in milling and analytically through a finite-elements method (FEM) s imulation of the cutting process. The treatments carried out were polishing and micro- and glass-blasting at various pressures. The initiation and pro gress of the tool failure was depicted through scanning electron microscopy (SEM) and energy-dispersive X-ray microspectral investigations of the cutt ing edges used. Furthermore, FEM simulation of the contact between the tool and the workpiece enabled the development of a quantitative description of the influence of the substrate and coating surface roughness on the mechan ical stresses occurring, and thus on fatigue-induced coating failure and we ar. The coating stress-strain curves and their fatigue endurance were deter mined through FEM-supported nanoindentation measurements and impact test re sult evaluations, respectively. In all FEM calculations conducted, multilin ear constitutive laws were applied for modeling the coating and the substra te. The experimental and computational results obtained quantitatively exhi bit the influence of the substrate, as well as of the coating surface treat ments, on the cutting performance of the HM insert. (C) 2001 Elsevier Scien ce B.V. All rights reserved.