Study On Microstructure And Properties Of Friction Stir Welded Joint Of 5052/6061 Dissimilar Aluminum Alloy Plate

The 5052-O and 6061-T6 dissimilar aluminum alloy plates with the thickness of 15 mm were welded by friction stir welding(FSW) which included two kind of welding process: Single-side FSW and Double-side FSW, The influence of welding process parameters, microstructure, mechanical properties, corrosion resistance of 5052/6061 dissimilar aluminum alloy plates with double side FSW joints were studied, and a comparative analysis of two kinds of welding(Single-side FSW and Double-side FSW) joints' microstructure and mechanical properties, and explore the effect of alloying elements on the microstructure and mechanical properties of the joint. The main research results are as follows:(1) The double-sided processes of friction stir welding were used on dissimilar 5052-O/6061-T6 aluminum alloy with the thickness of 15 mm. Effect of friction stir welding process parameters on the mechanical properties of the welded joints were studied. The results show that the effect of tool rotation speed is remarkable, the second is tool traverse speed,the last is shoulder plunge depth. When the tool rotation speed? tool traverse speed and shoulder plunge depth were 1600 r/min?90mm/min and 0.15 mm respectively, which is the optimized scheme.(2) Through electrochemical corrosion experiment test shows that the corrosion resistance of welded joint(which is on the optimal process parameters) is better than the base metal; the reasonable friction stir welding process parameters, which not only make with excellent mechanical properties, and can make them get better corrosion resistance.(3) The 5052-O and 6061-T6 dissimilar aluminum alloy plates with the thickness of 15 mm were welded by friction stir welding(FSW) which included two kind of welding process: Single-side of FSW and Double-side of FSW, by comparing organization and mechanical properties of two kind of welding process' s welded joint, the results show that the performance of double-side FSW joint is superior to the performance of single-side FSW joint.(4) Effect of the addition of alloy elements on the mechanical properties of the welded joints(which is on the optimal process parameters) was studied. The results show that the addition of alloy elements has no effect on the mechanical properties of the welded joints; however, micro-hardness test shows that the alloy elements added to improve welding zone average micro-hardness values.