Experimental Research And Numerical Simulation Of Laser Penetration Welding Of Dissimilar Metal Of Car

Lightweight has become the important measures to control auto emission reductions. Compared with the traditional fusion welding, the laser welding has lots of advantages, such as, high production efficiency, little deformation, small influence area, etc. Laser welding is the ideal way of combine different lightweight metals in the automobile industry. In this paper,6016aluminum alloy,5083aluminum alloy and galvanized steel are choosen as the research object, the deep penetration laser welding experiment is designed, numerical simulation and experimental method are used. The penetration, width and temperature field distribution of the welded joints and weld micro structure are sttudied by using the thermocouple temperature measurement system, horizontal optical microscopy, scanning electron microscopy and PROCAST and ANSYS finite element commercial software, a new investigative mean for laser welding of dissimilar metal is provided and the important theory and experimental foundation for the application and popularization of laser welding different lightweight metal are also offered in this paper.The model of steel and aluminum, aluminum and aluminum dissimilar metal laser deep penetration are established. Using the established model, the temperature field, width and penetration of the weld are calculated. Temperature measurement experiments results are agreement with the simulation results.Different process parameters including welding power, spot radius, the amount of heat input, welding speed have an effect on the weld appearance during the steel and aluminum and various aluminum alloy laser welding process. The rule of weld type under different heat input is studied, the reasons of the defects under different process by laser welding are also analyzed to improve the mechanical properties of welded joint and the joint quality.Laser welding practical experiments are done for the steel and aluminum, it is found that when the welding speed is25mm/s, light spot radius is0.9mm and laser power is between1400W and1600W, steel and aluminium welding seam surface is bright and clean, and the weld around the bite edge has no obvious deformation, but the fusion situation is bad, when laser power is between1900W and2100W, it is easy to cause weld defects, while laser power is between1600W and1900W, good weld formability is seen.Laser welding practical experiments are also done for aluminum and aluminum dissimilar metal, it is found that when the power is2600W, the welding speed is75mm/s, the amount of coke is zero, the welding heat input is not enough, it appears false welding phenomenon, when power is2900W, the results show that the sample surface form a continuous weld without splash, inclusion and macroscopic crack. The penetration are good formed with a uniform melting width.