Product Code: ICA13_1102

Laser Welding of Niti to Stainless Steels
Authors:
Edwin Mok, University of Nottingham Ningbo China; Ningbo Peoples Republic of China
H.C. Man, Department of Industrial and Systems Engineeringhong, the Hong Kong Polytechnic University; Kowloon Hong Kong
Presented at ICALEO 2013

NiTi shape memory alloy has played a leading role on recent development of innovative biomedical devices, sensors and consumer products. However, its high material cost, low formability and poor weldability are critical shortcomings that hinder its further applications. To reduce the material cost, manufacturers prefer to use Nitinol only for the critical part and other alloys for the rest of the component. Since low formability prohibits complicated shape to be formed, fabrication by joining different parts is a possible route. Both issues can be overcome by joining Nitinol with different metals. Among many joining techniques explored, laser welding is most likely to meet the requirements of medical device. However, fusion welding of Nitinol with stainless steel has a fundamental problem because titanium and iron would form brittle intermetallics and induce weld crack. This project will investigate the feasibility of laser sandwich-fusion welding Nitinol and stainless steels using various metal as interlayer.