Fatigue Characteristics and Microstructures of Laser‐ and Non‐Laser Welded Low‐Cost Ti‐4.5Al‐2.5Cr‐1.2Fe‐0.1C for Use in Next Generation Aircrafts

Ti-4.5Al-2.5Cr-1.2Fe-0.1C referred to as KS Ti-531C is a newly developed low cost titanium alloy for use in next-generation aircrafts by adding inexpensive elements such as C, Fe, Al and Cr. There is a possibility for the formation of TiCr and/or TiCr2 after a long heat treatment or welding. Therefore, relationships between the microstructures and fatigue properties of KS Ti-531C subjected to several heat treatments as well as laser welding were investigated systematically. The results showed that the fatigue strength of laser-welded KS Ti-531C was lower than that of non-laser welded KS Ti-531C.