Investigation on porous NiMnGa alloy and its composite with epoxy resin.

• Porous NiMnGa alloys with large size pores are prepared by one-step sintering method. • Porous alloys with different porosities have similar phase transformation behavior. • The composite is prepared by infiltrating epoxy resin into the porous alloy. • The composite exhibits a similar phase transformation behavior to the porous alloy. • Mechanical property of the composite is effectively improved by synergistic effect. This article investigated microstructure, phase transformation and mechanical property of porous NiMnGa alloy and its composite with epoxy resin. The porous NiMnGa alloys with large pores and different porosity exhibited a similar martensitic transformation behavior but with reduced martensitic transformation temperature as compared to that of the original powder. The porous alloys exhibited low mechanical strength and ductility due to the existence of large size pores. After compositing with epoxy resin, the mechanical strength and ductility of the porous alloy had been apparently enhanced due to the synergistic effect between the polymer and porous alloy. In addition, the composite demonstrated a martensitic transformation behavior similar with that of the porous alloy, indicating that the constraint effect of polymer matrix on the phase transformation of the porous alloy could be neglected. The combination of porous NiMnGa alloys with continuous structure and polymer could provide a promising way to make NiMnGa/polymer composites with better performance than the composites consisting of NiMnGa particles and polymer. [ABSTRACT FROM AUTHOR]