Investigation of the rotary swaging and heat treatment on the behavior of W- and γ-phases in PM 92.5W–5Ni–2.5Fe–0.26Co heavy alloy

The effects of rotary swaging and different heat treatment procedures on the W- and γ-phases behavior of PM 92.5W–5Ni–2.5Fe (wt.%) heavy alloy microalloyed with cobalt have been studied. The investigation was performed on sintered and cold rotary swaged samples deformed with area reduction from 5 to 30%. One batch of swaged samples was annealed in vacuum at 1473 K for 7.2 ks and then furnace-cooled to the room temperature, whereas another batch of swaged samples was previously deformed 30% and strain aged in argon and nitrogen in the temperature range between 473 and 1123 K for 3.6 ks. Strengthening of W- and γ-phases was investigated by applying microhardness measurements. Effects of the degree of deformation, parameters of heat treatment and strain aging on microstructural changes have been studied. Mechanical properties, hardness and microhardness of phases as a function of the degree of deformation and heat treatment were analyzed by applying statistical modeling. A correlation between deformation behavior of phases, effect of heat treatment and alloy properties was also discussed.