Solid-particle erosion of an anodized Mg alloy

Solid-particle erosion studies were conducted on a hardened Mg alloy (WE43A-T6) and the same alloy that had been anodized to produce a ≈12 μm oxide layer. Angular alumina particles of nominal diameter 63 or 143 μm traveling at 60 or 120 m/s impacted the targets at 20° or 90°. Steady-state erosion rates were determined as weight loss of a sample per weight of impacting particles. Under these erosive conditions, the oxide coating on the WE43A-T6 alloy was removed quickly. Weight-loss data indicated that the alloy underlying the anodized layer eroded measurably faster than the as-heat-treated alloy, but that below depths greater than ≈80 μm, the two alloys eroded at nearly equal rates. The near-surface more rapid erosion rates for the anodized alloy were attributed to loss of ductility due to internal oxidation from the anodizing process.