Study On The Low Power Nd:YAG Pulsed Laser Welding Ability Of The Al-Mg Department Aluminum Alloy

As a newly emerged welding method, the laser welding of aluminum alloy is being more and more valued, because its advantage of high efficiency, low energy consumption and good welding quality.In this paper, we mainly talked about the Nd:YAG pulsed laser welding of a5000department Al-Mg alloy, studied the variation principle of the welding quality.By using the method of the single variable, the effect of the welding current, welding speed, pulsing frequency, pulsing width and the defocus on the welding quality of the workpiece was discussed; Talked about the changing trend of the welding depth, welding width, the ratio of the welding depth to the width, the tensile strength and the hardness. On this basis, the comprehensive test of the effect on the aluminum’s welding ability was conducted by using the selected welding parameters.Then, on the basis of the preceding, the welding tests were carried out by changing the surface state of the workpiece.Studied the welding forming and the welding quality under the surface state of sandpaper, alkali corrosion and anodic oxidation.comparaed with the welding pieces of none surface treatment, It was founded that the stability of the welding process and welding quality were improved in a certain degree when the workpieces were treated by the sandpaper and alkali corrosion, but the degree of the improvement were not obvious. However, the stability of welding process of the wokpiece under the surface of anodic oxidation were significantly improved, the color’s change of the weld puddle and the droplets spattering were significantly reduced, besides, the tensile strength of the workpiece was also significantly increased.The further welding tests were conducted by changing the welding process. Studied the welding principle of the work piece under the welding method of two times, double sides, end groove and alloy powder preset at the end surface. The test certificate-ted that the welding process and the welding quality is significantly improved after changing the welding method, the welding strength of the welding piece was highly improved especially after the powder preset at the end surface.Finally, the existence of the stoma, crackle, surface downwards and the undercut in the weld line was analysised.Besides we also talked about the lamellar morphology, the variation of elements, the tensile properties and characteristics and the microstructure of the weld line.The research findings of this paper has done a favor to the further understanding of the interaction between the material and laser beams, how to improve the absorptive of the laser and how to improve the stability of the welding process and quality while welding the aluminum by using the laser.