Effect of Baking on Hydrogen Embrittlement of 6061-T6 Aluminum Alloy by Various Electroless Ni-P Plating

Effects of two kinds of electroless Ni-P plating and a baking treatment after plating on the temperature-dependent hydrogen desorption behavior, tensile properties, and fatigue properties of 6061-T6 aluminum alloys were investigated, and the results were discussed. Thermal desorption analysis (TDA) revealed that each plating causes hydrogen absorption into the substrate, which was found to reduce the mechanical properties. After plating, the baking treatment significantly reduced the hydrogen amount in the substrate and improved the mechanical properties. The fatigue strength of the low-phosphorus type plated specimen was increased to 160 MPa by the baking treatment, and a fatigue ratio of over 50% was obtained.