Characterisation of the wear behaviour of polycrystalline diamond (PCD) tools when machining wood-based composites

Wood-based composite materials are used extensively for interior and exterior construction applications. These materials are typically pressed into sheet form and then machined to the required size and profile using cutters such as circular saws, band saws and routers. These cutters are tipped with hard cutting tool segments that perform the cutting and prolong the life of the tool. Polycrystalline diamond (PCD) segments are increasingly used in woodworking due to extended tool life resulting from their superior properties over traditional tool materials. Estimating the degree and nature of tool segment wear for the machining of wood-based composite materials is difficult due to the long tool life involved. Under controlled machining conditions abrasive wear dominates, where the tool wears evenly with the amount of material cut. The tool sliding distance is a useful determinant of abrasive wear. This paper outlines a method for calculation of the tool sliding distance for the circular sawing of sheet materials based on a dimensional analysis. Using this information, a tool wear test was designed to test the performance of PCD tooling when sawing these products. Abrasive and chipping wear modes were found for sawing different materials. The underlying wear mechanisms appeared to be dislodgement of PCD grains and micro-fracture of the PCD respectively.