Friction Stir Welding of Precipitation Hardened Ni Based Alloys

Commercial Waspaloy plates with two different initial microstructures (annealed and aged) were joined by Friction Stir Welding (FSW). This study presents the evolution of the grain structure, and precipitation, dissolution and reprecipitation of the gamma' phase during FSW using Optical Microscopy, Scanning Electron Microscopy and Transmission Electron Microscopy. The relationship between microstructure and microhardness is also discussed.