Increasing of cutting performance of PVD coated cemented carbide inserts in chipboard milling through improvement of the film adhesion, considering the coating cutting loads

Coated cemented carbide cutting inserts that had been pre-treated to remove from their surface the remaining highly deformed cobalt binder layer were examined by carrying out a series of cutting experiments, in order to evalu ate their performance when used in chipboard milling. The chip formation me chanism and the tool loading, required to determine the occurring stress di stribution in the applied coatings during chipboard milling, was analytical ly investigated by means of a developed FEM simulation of the material remo val process, verified through cutting force measurements. The coating stres ses during milling, due to cutting loads, as appropriate FEM calculations c oncerning their distribution on the tool rake face show, are below the coat ing's fatigue strength. The coating and the tool wear development are mainl y caused by abrasion mechanisms at low cutting temperatures. The investigat ions indicated that removal of the Co binder phase by pre-treatment of the tool's substrate through grit blasting or chemical etching, results in bett er adhesion properties, therefore providing superior wear behaviour to the tool. (C) 2000 Elsevier Science B.V. All rights reserved.