Description

Shape memory alloys (SMAs) are a unique class of materials with the ability to recover their shape when the temperature is increased. An increase in temperature can result in shape recovery even under high applied loads. SMAs can also absorb and dissipate mechanical energy by undergoing a reversible hysteretic shape change when subjected to applied mechanical cyclic loading. These characteristics have made SMAs very popular for applications such as sensing and actuation, absorption and vibration damping. The application of SMAs spans a wide variety of industrial sectors such as aerospace automotive, biomedical and oil exploration. The demand of joining techniques for SMAs has become of great importance, as their functional properties, namely shape memory effect and superelasticity, present unique solutions for state-of-the-art applications. An investigation was conducted on laser welding of NiTi alloys aiming at correlating the mechanical cycling behavior and the microstructure obtained.