Study of low-temperature isothermal annealing in the PM Cu-Pt alloys after plastic deformation

Abstract

The investigation was performed on pure sintered (PM) copper and dilute PM copper-based alloys with 3 and 5.9 wt.% of platinum. Investigated PM samples were obtained using the standard powder metallurgy technique by mixing the elemental powders in proper ratio followed by pressing in hydraulic press and sintering in a hydrogen atmosphere. The PM samples were further cold deformed by rolling at ambient temperature to a total rolling reduction of 60 %. On pre-deformed samples, the low-temperature isothermal annealing up to the 100 hours was accomplished. During all stages of isothermal annealing, the values of Vickers hardness, micro-hardness, and electrical conductivity were measured. Also, the microstructure was analyzed using the scanning electron microscopy (SEM). This investigation has shown a slight increase in all measured properties for both dilute Cu-Pt alloys. An increase in mechanical properties was some more pronounced for more alloyed Cu-5.9wt%Pt alloy. During the low-temperature isothermal annealing, there were no significant changes in properties for pure pre-deformed copper.