The wear characteristics of some cemented tungsten carbides in machining particleboard

Abstract

This work is focused on developing an understanding of the wear mechanisms of cemented tungsten carbide tools in machining particleboard. Cutting experiments were conducted on several grades of cemented tungsten carbide tools using a high speed lathe, and their wear characteristics were determined. It was found that wear occurred predominantly on the clearance face of the tools for most grades tested. It was also found that the amount of wear after the same cutting distance correlates well with the bulk hardness of the tool material. The amount of wear generally decreased with an increase in hardness, a decrease in grain size and a decrease in binder content of the cutting tool material. Examination of the worn surfaces inside a scanning electron microscope showed that the cutting edge was worn by preferential removal of the metal binder phase from between the tungsten carbide grains. It is suggested that removal of the binder weakens the bond between the tungsten carbide grains leading to their mechanical removal from the clearance face. It is concluded that the main wear mechanism for cemented tungsten carbide tools in machining particleboard is the removal of the binder phase by plastic flow and micro-abrasion, which is followed by fragmentation and dislodging of the WC grains.