STRUCTURAL CHARACTERIZATION BY X-RAY DIFFRACTION OF LASER WELDED SHAPE MEMORY ALLOYS

The demand of emerging joining techniques for shape memory alloys (SMA) has become of great importance, as their functional properties, namely shape memory effect (SME) and superelasticity (SE) present unique solutions for state-of-the-art applications. Literature shows that significant efforts have been conducted on laser welding of these alloys, although very limited results concerning mechanical properties are repeatedly achieved. A better understanding of the mechanical behaviour of these welded joints may be got through a detailed analysis of the structural characteristics of the material from the base metal to the weld bead. Such studies have been carried out on a series of Ni-rich Ni-Ti SMA laser welded plates using synchrotron radiation.