A Study Of Aluminum Alloy Laser Welding Process

Aluminum alloy is an important light metal material in industry. Compared with aluminum alloy traditional welding technology, laser welding process has many advantages. Laser is a kind of high energe density hear source. It has high welding speed and small hear input. The deformation of welding parts is slight and the product quality is excellent. The research object is5052aluminum alloy, its thickness is1.5mm. It’s a study of aluminum alloy continuous and pulsed laser welding process.The defocus amount, laser output power and welding speed were optimizated in aluminum alloy laser welding experiment.Through the analysis of welding sample weld forming, mechanical property, microstructure and microhardness, the best parameters of aluminum alloy continuous and pulsed laser welding were obtained. The analysis of mechanical property showed that the welding joint tensile strength of aluminum alloy continuous and pulsed laser welding could reach to84.43%and91.80%of the metal base tensile strength, both of them have high tensile strength. The analysis of microstructure showed that the microstructure of aluminum alloy continuous laser welding was the same with the microstructure of aluminum alloy pulsed laser welding. There were a small amount of MgSi2and FeAl3particle in the matrix of metal base α(Al). The microstructure of heat affected zone was dendritic crystal and the microstructure of weld was axis crystal. The crystal of weld was the smallest one and the microstructure of weld was densest. The microhardness of weld reached a maximum value.In addition, the weld forming and tensile strength of two kinds of welding process was ideal. However, due to the intermittence of pulsed laser output, the molten pool was stirred more strongly. It’s good for the floating of bubbles. The porosities were suppressed effectively. The strong stirring of the molten pool made the elements to distribute uniformly. The crack were suppressed effectively. Therefore, the defects such as porosities and cracks were controlled effectively by pulsed laser welding process. The quality of pulsed laser welding is more excellent. Compared with continuous laser welding, the tensile strength of pulsed laser welding joint increased by about6%.