Effect of compaction pressure, sintering temperature and recovery heat treatment temperature of powder metallurgical Fe-20Mn-5Si-5Ni-8Cr shape memory alloy

This study brings out the effects of compaction pressure, sintering temperature, and recovery heat treatment (RHT) temperature on the Fe-20Mn-5Si-5Ni-8Cr alloy. A mechanically determined wt% alloy was synthesized, compacted, sintered and the RHTs were conducted at three different temperatures. The microstructural investigation disclosed the amount of fcc γ austenite, stress-induced reversible hcp ε martensite, bcc ά martensite and π precipitate present in the Fe-20Mn-5Si-5Ni-8Cr alloy during the entire shape recovery process. The shape recovery property degrades whenever the concentration of stress-induced bcc ά martensite, strain-induced bcc ά martensite and π precipitate rises. Three key process parameters, such as 1200 °C sintering temperature, 750 MPa compaction pressure and 400 °C RHT were employed to achieve the best shape recovery performance. Graphical abstract