Analysis of the Microstructure and Hardness of Aluminum Alloy Gradient Plate Prepared by Friction Stir

The aluminum alloy performance gradient plate was prepared by friction stir joining. Analysis results of the macro morphology, microstructure, and hardness of the aluminum alloy performance gradient plate prepared under various parameters show that when the feed speed of the stirring tool is 250 mm/min, the downward pressure of the stirring tool is 6.6 mm, and the rotation speed of the stirring tool changes from 200 rpm to 800 rpm. The macroscopic morphology of the aluminum alloy gradient plates prepared by the method first changed from burr to smooth, and vice versa. There is a different cross-section morphology of the prepared aluminum alloy gradient plates, however, the aluminum alloy plates are stirred and involved with each other, and the grains of the prepared plates are refined. The hardness of the upper and lower surfaces of the aluminum alloy gradient sheet decreases, whereas that of the upper surface of the side increases, and that of the middle and bottom sides also decreases. However, the hardness of the middle side of the sheet prepared with the rotation speed of the stirring tool at 800 rpm increases, but that of the bottom side still decreases. Obtained through analysis that the performance of the aluminum alloy gradient sheet prepared at the stirring tool rotation speed of 500 rpm increases in equal proportion to achieve a good performance gradient change.

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This study was financially supported by the Key Research and Development Project from Anhui Province of China (Grant No. 202004a05020025 and Grant No. 202104b11020011), Key Project of Natural Science Research in Universities of Anhui Province (KJ2021A1042), the China Postdoctoral Science Foundation (No. 2016M600411), the Open Research Project of Anhui Simulation Design and Modern Manufacture Engineering Technology Research Center (Huangshan University) (No. SGCZXZD1801 and SGCZXZD1901), Huangshan University Postdoctoral Support Project (No. 2020bkjq002), and Anhui Provincial Excellent Young Talents Support General Project, China (No. gxyq2019086), Anhui Province Construction Machinery Intelligent Manufacturing Key Laboratory Open Subject (No. IMCM2021KF01), Anhui University Collaborative Innovation Project (No. GXXT-2021-092).