Effects of original microgeometry on the surface quality of AMg6 aluminum alloy parts following ultrasonic surface plastic straining

We study the effect of original surface microgeometry and the number of indenter passes on the microhardness and roughness of the surface layer of products treated by ultrasonic surface plastic straining. The study was conducted using cylindrical specimens made of AMg6 aluminum alloy. Ultrasonic surface plastic straining was performed according to a tangential input of ultrasonic vibrations for the number of indenter passes varying from 1 to 5. The original roughness of aluminum specimens ranged from Ra 0.44 to Ra 3 µm. The quality of the surface treated by ultrasonic surface plastic straining was assessed based on roughness and microhardness parameters. For the selected range of original surface roughness, the roughness and microhardness of the specimens reached stable values after 1-2 intender passes. The efficiency of ultrasonic surface plastic straining for products made of AMg6 aluminum alloy is largely determined by the microgeometric and physicomechanical characteristics of the original surface, as well as by the number of processing cycles. Thus, a significant decrease in roughness and increase in microhardness were observed in the formed specific cellular microgeometry of the surface. Increasing the number of passes above 1-2 appears ineffective in terms of further improving the quality of the surface layer. The obtained results can be used to optimize technological processes in mechanical engineering, aviation, automobile, and other industries, optimize the selection of finishing operations, ensure contemporary quality requirements for the processed surface of aluminum alloy products, and increase the economic efficiency of production.