The effect of cold deformation on grain refinement of heavy metals

Rapid heating experiments, of the order of seconds, were performed on a 90%W–7%Ni–3%Fe alloy, which was cold worked by rotary swaging to 50 and 82% reduction in diameter. It was found that even very short periods of heating above the melting temperature of the matrix causes the partition of the elongated tungsten grains into small round ones. The higher the degree of deformation, the shorter the period of heating for the partition of the tungsten grains. The grain refining process is carried out by the penetration of the molten matrix into the subgrain boundaries of the tungsten grains.