بررسي اثر متغيرهاي فرآيند عمليات حرارتي بر خواص مكانيكي و ريزساختار آلياژNi-40%Ti

Effect of Heat Treatment Variants on Mechanical Properties and Microstructure of Ni-40%Ti Alloy

In this paper, effect of time and temperature of aging on hardness and microstructure of 60 Nitinol (nickel - titanium alloy with 60% wt. nickel) has been studied. After hot working, the specimens were solution treated for 6 h at 1100°C and then aged at various temperatures between 400 to 900°C for 30-480 min. The microstructures of the specimens was studied by scanning electron microscopy (SEM). The results showed that with increasing aging time at a constant aging temperature, an almost a constant hardness was obtained. The hardness decreased as the aging temperature increased to about 700°C. Further increase in aging temperature increased the hardness of the samples. At a constant aging temperature, with increasing aging time, the size of precipitations was increased.