Characteristics of diamond sawblade wear in sawing

The characteristics of the surfaces of worn diamond segments in circular saws for the sawing of granite have been investigated. A scanning electron microscope and a toolmaker's microscope were used to examine the worn surfaces, and radial sawblade wear and grinding ratio during sawing were measured. Experimental results indicate that the diamonds on the working surface for a heavy trimming operation can be classified as whole (without significant wear), micro-fractured, and macro-fractured crystals; also pullout craters occur. The transition from a free-cutting action to a less efficient cutting occurs when the proportions of whole crystal, fractured particle, and grit pull-out are about one-third. When the proportion of particle fracture (particularly macro-fractured particles) and/or grit pull-out exceeds one-third, the cutting ability of a sawblade becomes less efficient and, in an extreme case, leads to sawblade failure. Conversely, a sawblade containing a higher proportion of whole crystals and a lower proportion of macro-fractured particles cuts more efficiently. Copyright (C) 1995 Elsevier Science Ltd