Mechanical Properties and Corrosion Rate of Friction Stir Mg-Alloys AZ31B-H24 Welded Joints Produced by a Triangle Pin at Different Tool Rotation Speeds

This chapter presents a meticulous investigation into the mechanical properties and corrosion behavior of friction stir welded AZ31B-H24 magnesium alloy joints, focusing on the unique triangle pin geometry. The study reveals that higher tool rotation speeds, particularly 2280 rpm, result in finer grain structures and enhanced tensile strength, reaching up to 212.2 MPa. The microhardness distribution exhibits a distinctive 'V' shaped profile, with the lowest hardness values observed in the stir zone. Notably, the corrosion resistance of the welded joints is significantly improved at higher rotation speeds, with the lowest corrosion rate of 0.015 mm/year achieved at 2280 rpm. The chapter provides a detailed analysis of the fracture surfaces and microstructural changes, offering valuable insights into the optimization of friction stir welding parameters for magnesium alloys. The findings underscore the critical role of pin geometry and rotation speed in determining the quality and performance of welded joints, making this study a significant contribution to the field of welding technologies and materials science.