Laser surface alloying of NiTi shape memory alloy for the reduction of Ni ion release

摘要

Interests in applying NiTi shape memory alloys as metallic implant materials have grown immensely in recent years due to their unique shape memory, super-elastic and corrosion resistance properties. However, concern has been raised for its long term applications in the human body because of the risk of release of Ni ions into the body. Ni ion is toxic and will cause allergic response in the human body. Ni ion release was found mainly due to the fretting corrosion of the alloy. This paper reports the results of laser surface alloying of NiTi with Molydenum. The corrosion and mechanical properties of the alloyed surface will be discussed and the reduction of Ni ion release rate will be reported.