In the present study, a novel kind of NiTiW
shape memory alloy with chemical composition of Ni43.5Ti45.5W11 (at.%) has been successfully developed with excellent X-ray radiopacity by the introduction of pure W precipitates into the NiTi matrix phase. Its microstructure, X-ray radiopacity, mechanical properties, corrosion resistance in simulated body fluid, hemocompatibility and in vitro cytocompatibility were systematically investigated. The typical microstructural feature of NiTiW
alloy at room temperature was tiny pure W particles randomly distributing in the NiTi matrix phase. The presence of W precipitates was found to result in enhanced radiopacity and microhardness of NiTiW
alloy in comparison to that of NiTi binary
alloy. NiTiW
alloy exhibits excellent shape memory effect, and a maximum shape recovery ratio of about 30% was obtained with a total prestrain of 8% for the NiTiW
alloy sample. In the electrochemical test, NiTiW
alloy presented an excellent corrosion resistance in simulated body fluid, comparable to that of NiTi
alloy. Hemocompatibility tests indicated that the NiTiW
alloy has quite low
hemolysis (lower than 0.5%) and the adherent platelet showed round shape without pseudopod. Besides, in vitro cell viability tests demonstrated that the cell viability is all above 90%, and the cells spread well on the NiTiW
alloy, having polygon or spindle healthy morphology. The hemocompatibility tests, in vitro cell viability tests and morphology observation indicated that the NiTiW
shape memory alloys have excellent biocompatibility. The excellent X-ray radiopacity makes the NiTiW
alloys show obvious advantages in orthopedic, stomatological, neurological and cardiovascular domains where radiopacity is quite important factor in order to guarantee successful implantation.