Research on surface modification of anodized aluminum alloy using piezoelectric machine hammer peening

Piezoelectric machine hammer peening (PEMHP) is a mechanical surface treatment method that hammers the workpiece surface by an oscillatory spherical tungsten carbide tool. The experiments have been conducted to investigate the surface modification of 6016 anodized aluminum alloy using PEMHP, including surface roughness, surface topography, and hardness. The experimental and simulation results indicated that PEMHP has better surface smoothing effect than milling and improves the surface integrity. The hardness of anodized aluminum alloy increases about 14-33% with different peening parameters. The influences of peening parameters on surface roughness, surface topography, and hardness are discussed. It is found out that peening parameters have strongly influenced surface integrity, especially line pitch. Therefore, PEMHP can be a subsequent machine process for aluminum alloy after anodic oxidation to improve surface integrity and hardness further.