A study of the performance of diamond wire in hard natural stone
Diamond wire has been developed as a flexible cutting tool and is used by the natural stone industry for the quarrying of blocks and for subsequent squaring, slabbing and shaping operations in the stone yard. The performance of diamond wire depends on how its beads wear and the optimum life is achieved when the diamond particles are consumed in a desired manner from the periphery of each bead. This thesis covers diamond related aspects which influence the performance of diamond wire. An investigation is made of the wear of diamond particles in the bead matrix and a comparison is made with diamond particle wear found in other diamond tools. Bead matrix wear progressions are described, pertaining to diamond wire sawing operating conditions. An equation of chip thickness in relation to the cutting action of a diamond segment is derived and chip thicknesses are determined for wire sawing operating parameters used in different stone types. The sawability and abrasivity properties of stone are evaluated and are compared with corresponding results of diamond wire life. Formulae are derived for the approximation of the length of cut and area sawn in quarrying and stationary wire sawing applications and for the forces acting on a bead over a constant cutting radius. A method of testing single diamond beads is used for comparative assessments of different diamond grades and the effects of applied load, cutting velocity and cutting rate are examined in relation to bead wear. High speed video imaging is used to analyse the dynamics of diamond wire in operation and the problems associated with uneven bead wear.
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