Micromechanism of polycrystalline cemented diamond tool wear during milling of wood-based materials

Well known and widely used in wood-based material machining, polycrystallin e cemented diamond (PCD) inserts undergo specific forms of wearing during m illing, depending on the material being machined. In the present work, observations were made on the micron and submicron sca le. Using an edge-tester tip of radius r = 0.2 mu m we found that milling f ibre board caused a uniform reduction of the cutting edge and that milling particle board caused large spalls with no change in the shape of the cutti ng edge. Images of the cross-sections of the casts of inserts revealed larg e losses and/or rounding of the edges worn off by both materials. Surface examination using scanning electron microscopy (SEM) on the nanomet er scale revealed a new mechanism of the wearing of PCD inserts, in additon to the spalling of individual microcrystals. The new mechanism involves th e 'peeling' of slices of the diamond ceramics. (C) 2000 Elsevier Science S. A. All rights reserved.