Effects of hydrogen on the tensile properties of electroless Ni-P plated 6061-T6 aluminum alloys

6061-T6 aluminum alloys (Al-Mg-Si alloys) are known to show low environmental hydrogen embrittlement sensitivity. However, this alloy containing 0.1% of iron shows a decrease in ductility when a large amount of hydrogen is previously charged in an atmosphere containing water. In this study, we investigated the effect of electroless Ni-P plating involved the removal of oxide film on the absorption of hydrogen and the hydrogen embrittlement sensitivity of a 6061-T6 aluminum alloy. It was shown that the ductility decreased immediately after Ni-P plating because a large amount of hydrogen was introduced into the alloys. In addition, the hydrogen embrittlement sensitivity changed according to the holding time after Ni-P plating at room temperature. The 6061-T6 alloy showed better resistance for hydrogen embrittlement when the alloy was kept at room temperature for 50 days after Ni-P plating. © 2021 The Japan Institute of Light Metals.