The book titled "Mg-Cr Fillers in Dissimilar FSW Joints" by Sasikumar A explores the application of Mg-Cr fillers in the context of dissimilar friction stir welding (FSW) joints. FSW is a solid-state welding technique widely used for joining various metals, and this book specifically focuses on the welding of dissimilar materials, specifically magnesium and chromium alloys.The book delves into the fundamental aspects of Mg-Cr fillers, including their composition, properties, and interfacial reactions. It provides a comprehensive analysis of the intermetallic compounds formed during the welding process and their impact on the microstructure and mechanical properties of the joints. The metallurgical bonding, interfacial shear strength, and interface morphology are thoroughly investigated, along with the influence of welding parameters and thermal cycles on joint strength and performance. Furthermore, the book explores the effects of interdiffusion, solid solution formation, and microstructural evolution on the joint integrity and mechanical properties. It discusses the role of grain refinement, microhardness, and interfacial diffusion in enhancing joint efficiency and stability. The impact of alloying elements, processing conditions, and filler materials on the overall thermal stability and weldability of dissimilar FSW joints is also addressed.