Effect of Cathodically Charged Hydrogen on the Microhardness of Pure Copper

The effect of hydrogen on the microhardness of pure copper was investigated after experiments conducted on specimens that hydrogen charged under different cathodic charging conditions. Microhardness measurements revealed that the introduction of hydrogen caused hardening on the surface of copper. The severity of the hardened region increased with either cathodic current density or charging time. Further charging increased the depth of the hardened region of copper. Ageing after charging can result in either complete or partial recovery of hardness, depending on the charging conditions.