Abstract
In this study, 6061-T6 aluminum alloys were plated with electroless Ni–P with different phosphorus content and three-point bending and rotating bending fatigue tests. The effects of hydrogen due to plating on mechanical properties were investigated. It was shown that the ductility decreased immediately after low-phosphorus type and high-phosphorus type Ni–P plating by three-point bending test because a hydrogen was introduced into the alloys. The fatigue strength of the low-phosphorus type Ni–P plated specimen was higher than that of the un-treated specimen, while that of the high-phosphorus type plated specimen was much lower. It is clear that the fatigue strength differs greatly depending on the phosphorus content in the plating film. 6061-T6 aluminum alloy have been reported to exhibit no hydrogen embrittlement in low strain rate tensile tests under wet condition. However, it was found that hydrogen embrittlement occurred when 6061-T6 aluminum alloy was plated with the high-phosphorus type electroless Ni–P and fatigue-tested on rotating bending machine.
This Paper was Originally Published in Japanese in J. Japan. Inst. Met. Mater. 87 (2023) 114–119.
Fig. 7 Relation between stress amplitude (
σa) and number of cycles to failure (
N) for the un-treated, Ni–P low-P type-plated, high-P type-plated and zinc plated specimens.
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