A Study on the Electroless Ni-Cu-P Alloy Plating of Al Base Hard Disk(I)Effect on some Properties of Electroless Ni-Cu-P Deposits by Electrolyte and Heat Treatment Condition

알루미늄 기판의 무전해 니켈-구리-인 합금도금에 관한 연구(I) 전해액 및 열처리 조건이 무전해 니켈-구리-인 도금층의 제 물성에 미치는 영향

Electroless Ni-Cu-P alloy plating of Al base hard disk was performed to investigate some properties according to the change of composition. It was found that the composition of Ni and Cu in deposits changed linearly with increasing the mole ratio of NiSO4.6H2O/CuSO4.5H2O. The increase in hardness by heat - treatment was confirmed to be associated with small size grained crystallization of the amorphous deposits. Acid resistance of all deposits layer. which had been heated up to 30$0^{\circ}C$, was found to be exellent when immersed in 1N-H2SO4 solution, and it showed more superior acid resistance with decreasing Cu content and with increasing P. The resistivity of the deposits heat treated became smaller at temperature more than 50$0^{\circ}C$, and it became largerly with increasing P content. Cu 44.1wt% alloy(C bath) showed the most superior non-magnetically stable characteristics after heat treatment. It was superiorly with higher temperature and with decreasing P content.