Microstructure, mechanical and shape memory properties of
Ti-55Ta-xSi biomedical alloys
Ti-55Ta-xSi biomedical alloys
(Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005, China)
Abstract: The effects of Si addition on microstructures, mechanical and shape memory properties of Ti-55Ta biomedical alloy were investigated. The results show that the microstructures consist of mainly α′′ martensite and a little β phase, and the grain size decreases obviously with increasing Si addition. When x = 0.2, small (Ti, Ta)3Si precipitates are formed at grain boundaries. With further increasing Si content, the amount of the precipitates gradually increases. The tensile and yield strength of Ti-55Ta-xSi alloys gradually increase with increasing Si addition, whereas elongation decreases. Ti-55Ta-0.1Si alloy exhibits the lowest elastic modulus and the best shape memory recoverable strain. It is revealed that the refinement of grain and the precipitation of (Ti, Ta)3Si phase are responsible to the changes of their mechanical and shape memory properties.
Key words: Ti-Ta alloy; grain refinement; tensile; shape memory effect