Lightweight NiTi shape memory alloy based composites with high damping capacity and high strength

An innovative method combining pore-forming technique, powder sintering and pressureless infiltration of light metal (Mg) was developed to successfully fabricate NiTi shape memory alloy based composites (i.e., Mg/NiTi). The Mg/NiTi composites possess excellent mechanical and physical properties, such as high damping capacity, high fracture strength and low density. The composites show higher compressive strength than the porous NiTi alloys and exhibit excellent superelasticity over 2%. The product of storage modulus and internal friction (EIF) is used to evaluate systematically the damping performance of Mg/NiTi composites by considering the synergy effect of internal friction and modulus, and several damping mechanisms have been identified.