Effects of various surface treatments on hydrogen embrittlement of 6061-T6 aluminum alloy were investigated. Rotary bending fatigue tests showed that electroless Ni-P plating on 6061-T6 reduced the fatigue strength considerably because of hydrogen absorbed into the substrate by plating. These findings suggest the possibility of evaluating hydrogen embrittlement of 6061-T6 by conducting rotary bending fatigue tests after electroless Ni-P plating.
Effects of constant temperature and humidity testing on the adhesive properties of phosphate-anodized AZ91D magnesium alloy were evaluated to produce multiple materials for lightening the fabrication of these materials. Phosphate-anodized AZ91D magnesium alloy, after immersion in dilute nitric acid solution, maintained strong adhesive strength even after constant temperature and humidity testing. These findings suggest that the anodization film is bonded chemically to the adhesive by the dilute nitric acid solution treatment.