AZ31B Magnesium Alloy Sheet Plastic Deformation And Its Laser Welding Research

Magnesium alloy by the advantages of lightweight high-strength and rich reserves of materials, has become the third metallic engineering applying structure material after steel and aluminum. Known as the "Green Engineering Materials in 21st Century." With the difference of plastic forming process of magnesium alloy specifications, the mechanical properties of magnesium alloy represent different, its production always has low precision and yield production, because of the unique hexagonal crystal structure result in its mechanical properties show strong anisotropy; thus enhance the mechanical properties studies could improve the process of magnesium alloy sheet, providing a practice importance theoretical basis for guiding the production.Research room temperature static mechanical properties of The thickness of 0.5mm,0.8mm,1.0mm and 2.0mm AZ31B magnesium alloy sheet, discovers that distortion directly affect the material microstructure processing, thereby affecting the mechanical properties and the mechanical properties are in accord with the Hall-Petch relation:materials has fine grain has excellent mechanical properties and show different mechanical properties based on different sample direction, indicating that magnesium is an anisotropic material.Tensile and cupping test on the plate, indicating that in the same dimension case of the material dimension can establish a good linear relationship, to show mechanical properties that material under different loading conditions and express in the form of equation. So breakthrough the bottlenecks that only uniaxial tensile can be used to study mechanical properties. Study on 1mm thick sheet of the AZ31B laser butt welding, research laser welding process performance, explore processing conditions of Nd:YAG pulsed laser welding magnesium alloy, recommended use filling material to improve its welding forming insufficient. Analysis mechanical properties, phase composition, microstructure, fracture morphology and the electrochemical corrosion of the welded joints. Analysis shows that mechanical properties decreased of laser welded joint compared with the magnesium alloy base metal, Welded joint shows more obvious brittle fracture, its grain size refined to about half of the base metal. There's no significant heat affected zone, weld zone is divided into three regions by different welding microstructure:â… -columnar grain zone,â…¡-large equiaxed grain area,â…¢-fine grain equiaxed zone.By the affection of grain refinement second phase and the continuous distribution of content increased Al, the corrosion voltage increased about 10.20% to basic mental, the corrosion current decreased about 6.42% to basic mental. The welded join corrosion rate slowed down, so the property of anti-corrosion improved. Beside the surface is much lower, the hardness of the welded joint is greatly enhanced, the pick value increased about 40% than the base metal.