Abstract
The Vicker's surface hardness (Hv) of pure and alloyed aluminum anodized in phosphoric acid (P samples) and in sulfuric acid (S samples) has been measured with scanning electron microscope. The influence of drying time, measuring load, anodizing electrolyte, film thickness, surface roughness and Al substrate on the hardness were studied. It was concluded that Hv is suitably measured with load of 25g and changes linearly with ratio of the film thickness to the impression depth (d/h). It was also found that the hardness of S samples could be obtained without the influence of Al substrate in the range above 4 of d/h. Results show that S samples are harder and less flexible than P samples and suggest that the surface roughness, which depends on the anodizing conditions, plays a predominant role in the surface hardness measurement.
