Laser welding of ultralight magnesium alloy

• Main Author: Tang, Wee Min.
• Other Authors: Zhou Wei
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Materials::Metallic materials::Alloys
• Online Access: http://hdl.handle.net/10356/16666
• Institution: Nanyang Technological University

Magnesium is the lightest metal because of their low density. It alloys have higher strength-to-weight ratios and heat conductivity than other alloys which make it suitable for weight saving constructions in many industries such as automobile, aerospace, telecommunication and microelectronics. Because of the increase applications of magnesium alloys, the joining of magnesium has become an important issue. Laser welding becomes an important technique for joining magnesium alloys as it decrease welding defects and allows for short clock cycles. The Nd:YAG laser system has become the most used system for welding magnesium alloy due to it fast, precise, and easy process during welding. In this study, the use of an Nd:YAG laser system welding for thin-plate AZ91D magnesium alloy was optimized. The welding cross section geometries were grind, polish and determined by optical microscopy analysis. Some important laser processing parameters such as laser power, welding speed, and shielding gas flow and their effects on the welding quality are discussed. The characteristics of the microstructure and the hardness of the joints were analyzed by optical microscopy, scanning electron microscopy (SEM) and hardness testing.