Effect Of Ultrasonic Tempering In Comparison With Thermal Tempering On Hardened High Carbon Powder Metallurgy (PM) Produced Samples

In this study, the effect of high-power ultrasonic treatment (UST) in comparison with common thermal tempering of Astaloy® CrS (0.85%Cr-0.15%Mo)-0.8%C pressed and sintered samples after quenching is investigated. Results from microhardness, EBSD, and XRD show a promising level of tempering in the samples just after 4 minutes of UST by decreasing the strain level in the specimen and dislocation annihilation, while the thermal annealing at 200° C for 1 hr resulted in more softening and lower hardness level. The results of this study confirm that the Ultrasonic treatment is an effective rapid and easy method with much lower energy consumption that can be good enough to stress relief the component after quenching and substitute the traditional tempering based on the application.