effect of alloy element on weld pool dynamics in laser welding of aluminum alloys
In this manuscript, the different series of aluminum alloy for dynamic laser welding of the molten pool were carried out on-site X- Imaging System of ray phase contrast. The experimental results show that the laser-irradiated metal evaporates immediately, resulting in a key hole. Then the metal around the key hole gradually melts with the heat of the key hole. The growth rate of the depth of the key hole is positively correlated with the total content of the low boiling temperature element (TCE) , The key hole depth and diameter of the stable stage are also the same. The longitudinal observation area of the molten pool is negatively correlated with the thermal conductivity of the aluminum alloy. The measured laser absorption rate has the same change trend with the ratio of the key hole depth to the diameter, and the highest absorption rate of 58% appears in the aluminum alloy laser welding with TCE equal to 2. 1%. In the aluminum alloy where the TCE is less than 2, the sharp fluctuation of the shape of the key hole is avoided. 1%, the surface tension and recoil pressure of the metal steam are balanced. To sum up, this paper first quantifies the influence of alloy elements on Weld dynamics in aluminum alloy laser welding. Aluminum Alloy is one of the key materials for weight loss of mobile body including electric vehicles (EV). Laser manufacturing is widely used in industry as an efficient method. Laser is used in welding, cutting, additive manufacturing, etc. The interaction between laser and material determines the quality of the product. However, high power density laser-induced key holes and molten metals are surrounded by solid metals, and these internal phenomena cannot be observed by traditional methods. Although the properties of the key holes and melting pools are given through simulation, these calculation results are rarely verified directly through experiments. In laser material processing, various methods are used to explore the dynamic behavior inside the weld. Using high-speed camera technology and specially designed structure, the movement of molten metal in the weld is observed. In this method, glass sheets and steel plates are arranged side by side and illuminated by laser on their interface. By placing the camera on the glass side, the internal behavior of the welding pool can be directly captured, which helps to better understand the key hole dynamics and flow of the molten pool. However, the structure of this particular design changes the thermal conductivity around the weld, and in laser processing the measured key hole size is significantly larger than the real size. Microfocused X- The ray transmission observation system was successfully used to study the key hole dynamics, which is the research Learn more about the absorption and stability of key holes in laser welding. However, due to the marginal difference in X-absorption performance, the interface between the molten pool and solid metal cannot be identified by this method Ray between liquid and solid state. Recently, X It is reported that the X-ray phase contrast imaging system can clearly capture the weld behavior and the process of pore formation, which first provides an effective method to quantify the real internal features in the welding. The researchers studied the welding quality of various series of aluminum alloy laser welding through experiments and simulations. These studies show that the aluminum alloy of different components has different welding properties, which is caused by the difference in the behavior of the welding pool. The latest paper published by John H. martin . In essence, in laser manufacturing, the composition of aluminum alloy (including nanoparticles of nuclear agents) will significantly affect the quality of the final product. Some researchers have found that the Mg element in the aluminum alloy evaporates during laser welding, which will affect the dynamic properties of the key hole and the final properties of the weldg. Hardness distribution, including welding defects such as edge biting and air holes. However, the relationship between aluminum alloys of different components and laser-induced weld behavior is still not fully understood. In this manuscript, X. The weld behavior and pore formation process in various series of aluminum alloy laser welding process were captured by ray phase contrast imaging system. The effects of alloy composition on the growth rate of small holes, the geometry of small holes and the absorption rate were discussed. The relationship between the longitudinal observation area of the weld and the thermal conductivity of the material is proposed. In this paper, the influence of alloy elements on the welding properties of aluminum is quantitatively studied.