Preparation of NiTip/WE43 Magnesium Matrix Composites by Friction Stir Processing

An effective technique of friction stir processing (FSP) to fabricate the NiTi particle reinforced WE43 magnesium (Mg) matrix composite was proposed. The microstructure of FSP specimens was examined by scanning electron microscopy (SEM) coupled with an energy-dispersive X-ray spectroscope (EDS). X-ray diffraction (XRD) was used for phase analysis. The results show that the composite possesses the shape memory effect. The low processing temperature effectively prevents the interfacial reaction between the NiTi particles and Mg matrix during FSP. Regardless of particle size, the NiTi particles are homogeneously distributed in the Mg matrix. In addition, compared with the Mg matrix, the yield strength, ultimate tensile strength, and elongation of the NiTip/WE43 composite are reduced by 33%, 12%, and 18%, respectively. Both the tensile strength and elongation reduces with increasing the size of as-received NiTi particles. The failure mechanism of the composite is interface debonding and the fracture of reinforced particles.