Research On The Performance Optimization And Evaluation Of Welded Cracks Of A6N01S-T5 Aluminum Alloys

With the development of industrial production in our country, aluminum alloy materials are playing more and more important roles in the process of industrial manufacture. In the process of aluminum alloy welding, the welding thermal cracking greatly reduces the quality of welded joints. In this paper, a kind of high sensitivity welding crack detection device is designed by ourselves, and three kinds of A6N01S-T5 aluminum alloy material produced by different manufacturers. The welding temperature field and welding stress in welding process were measured and calculated by numerical simulation and thermocouple measurement.The results show that: by means of thermocouple and numerical simulation technology,the limitation temperature of the BTR area is 620 ? and 465 ?. Also, in this area the mental of welding beam possess lowest average molding value; D self designed thermal crack sensitivity test device can effectively magnify the binding effect,regions with smaller thermal cracking tendency are detected.Through the calculation of welding temperature field and welding stress,the D material has excellent crack resistance ability, and F material has the highest hot crack sensitive performance, and when the loading rate is more stable, to a specific value, the cracking tendency of F material in the welding process is more obvious;compared with the low matching performance of 4043 and pure aluminum wire, the 5356 and 4047 wire show better matching performance with the base mental , there are different degrees of reinforcing particles dispersed in the molten pool after 5356 wire welding, this reinforcing particles can effectively improve the resistance to thermal cracking;microstructure analysis showed that Mg2Si, as the main strengthening phase of A6N01S-T5 aluminum alloy, has a strong ability of micro crack propagation while producing many narrow micro cracks. Fe, Cr and other elements can combine Al, Si elements to generate impurity phases. Around those impurity phases, it is easily to form micro crack; It can significant decrease sensitivity of hot crack by improving the liquidity of the internal metal in the weld solidification process.