電流パルスめっき法を用いて作製したNi/CuおよびNi/Ni-P多層膜の断面観察と耐摩耗性の膜厚依存性

抄録

To improve the wear resistance of deposited films, Ni multilayer films containing copper （Cu） or phosphorus （P） were prepared electrochemically by application of pulses of a constant current from a NiSO₄ aqueous solution in the presence of copper sulfate （CuSO₄） or phosphoric acid （H₃PO₃）. Films prepared on the copper （Cu） substrates have structures （Ni/Cu or Ni/Ni-P） that include a Ni layer of controlled thickness and a thin Cu or Ni-P layer, where the two layers （Ni and thin Cu layers or Ni and thin Ni-P layers） are laminated alternately. The wear resistance of the prepared Ni/Cu and Ni/Ni-P multilayer films was higher than those of conventional Ni-P bulk films or an Ni/Cu multilayer film composed of Ni and Cu layers having equal thickness. It is noteworthy that the Ni/Ni-P multilayer film wear resistance improved with decreasing thickness of the Ni layer, even for Ni layer distance less than 10 nm. The Ni/Ni-P multilayer exhibited the best wear resistance performance at the minimum Ni layer distance used in this study: 3 nm. A new wear resistive multilayer was developed.