CHARACTERISTICS OF DIAMOND SAWBLADE WEAR IN SAWING

The characteristics of the surfaces of worn diamond segments in circul ar saws for the sawing of granite have been investigated. A scanning e lectron microscope and a toolmaker's microscope were used to examine t he worn surfaces, and radial sawblade wear and grinding ratio during s awing were measured. Experimental results indicate that the diamonds o n the working surface for a heavy trimming operation can be classified as whole (without significant wear), micro-fractured, and macro-fract ured 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-f ractured particles) and/or grit pull-out exceeds one-third, the cuttin g ability of a sawblade becomes less efficient and, in an extreme case , leads to sawblade failure. Conversely, a sawblade containing a highe r proportion of whole crystals and a lower proportion of macro-fractur ed particles cuts more efficiently. Copyright (C) 1995 Elsevier Scienc e Ltd