Effect of NH4HCO3 Contents on the Microstructure of the Microwave Sintered Porous NiTi Alloys

In this paper, the porous NiTi alloys were prepared by microwave sintering, and the effects of NH4HCO3 contents on the microstructure of the porous NiTi alloys were studied. The microstructure of the porous NiTi alloys was investigated by optical microscopy, Archimedes drainage method, surface roughmeter and X-ray diffraction. The results showed that the porous NiTi alloys were mainly composed of NiTi, Ni3Ti, Ti2Ni and Ni, and the diffraction peaks of the non-equiatomic phases (Ni3Ti, Ti2Ni and Ni) increased with increasing the NH4HCO3 contents. At the same time, the porosity, pore size and surface roughness of the porous NiTi alloys increased with the increase of the NH4HCO3 contents.