Friction stir welding of Inconel alloy 600

Excerpt

Nickel-based superalloys have been developed to increase the energy efficiency, performance and to reduce the cost of industrial turbine engines and the other high temperature components. To manufacture a modern, flexible and high performance turbine system, joining or welding processes including gas tungsten arc welding (GTAW), electron beam welding (EBW), laser welding or friction stir welding (FSW) are generally required [1]. FSW, which was invented in 1991 by The Welding Institute (TWI), Cambridge, England [2], is a solid-state joining process. Since FSW involves no melting, this process eliminates the problems associated with fusion welding such as fumes, arc glare, spatter, solidification cracking, shrinkage, severe distortion and solidification stress. It also provides a significant economic advantage in terms of savings in the weld preparation time, welding time, consumable costs and labor rate for veteran technicians [3‐5]. Over the past 15 years, it has been proven to be a promising joining process for low melting point materials including aluminum and magnesium alloys. However, these materials represent less than 10% of the welded products in the world. On the other hand, high melting point materials, such as steel and nickel-based superalloys, represent more than 80% of the welded materials [6]. Therefore, it is very promising to apply FSW to high melting point materials. In this study, a new approach was made to join the Inconel alloy 600 by FSW, and the joint properties and microstructures were examined. …