INVESTIGATION OF THE WORN SURFACES OF DIAMOND SAWBLADES IN SAWING GRANITE

The worn surfaces of the diamond segments in circular saws for the saw ing of granite have been investigated. A scanning electron microscope and a toolmaker's microscope were used to examine the worn surfaces an d radial sawblade wear during sawing was measured. Experimental result s indicate that for the sawing of a hard South Africa red granite, the worn particles occurring on the segment surface are mainly of the mac ro-fractured crystal and/or pull-out hole type, making the sawblade cu t less efficient. When cutting a relatively soft pink granite, the res ulting worn particles produce a greater proportion of whole crystal an d micro-fractured grit on the worn surface and the amount of crystal p ull-out is also high, which causes the sawblade to cut efficiently dur ing sawing. Further, in order to obtain the optimum blade performance, the diamond breakdown and the pull-out of the sawblade must operate i n the correct wear mode. (C) 1997 Elsevier Science S.A.