Mechanical Properties of Sintered TiNi Shape Memory Alloys with Compressive Residual Stress

Abstract

The authors have proposed a functionally-graded shape memory alloy with varying Ni composition by combination of sintering and thermomechanical treatment. A powder metallurgy process has advantage of the easy adjustment of composition ratios. However, in general, strength, ductility, and fatigue life of a sintered material are low due to the poor density. To improve this problem, the authors employed secondary working into the fabrication process such as hot rolling for consolidation and ultrasonic shot peening for inducing compressive residual stress. In this study, the mechanical properties of the sintered shape memory alloy fabricated by above-mentioned process were revealed.