In situ diamond wires: Part I. The Cu–15 vol.% Nb high strength cable

Abstract

Commercial diamond wires are cutting tools used in the slabbing of dimension stones, such as marbles and granites, as well as in the cutting of concrete structures. This kind of tool consists of an AISI 316 stainless cable on which annular diamond segments (pearls) are set up with gap between them. This work intended to design a new route to process diamond wires, called “in situ” technology, whose fabrication involves mechanical conformation process such as rotary forging and wire drawing, copper tubes restackings and thermal treatment of sintering and recrystalisation. Cu–15 vol.% Nb composite wires were used as high tensile strength cable, covered with an external cutting rope made of bronze 4 wt.% diamond composite, along the overall wire surface. Therefore, this work shows the Cu–15 vol.% Nb composite manufacturing route. Investigations on the mechanical behaviour and microstructural evolution showed an ultimate tensile strength (UTS) of 960 MPa, and strain of 2.0%. This anomalous strength increase has occurred because niobium filaments attained a ribbon like shape during processing, thus acting as barrier to copper dislocations.