2003 年 71 巻 4 号 p. 260-265
The present investigation examined how to prevent Ni-P deposition through imperfections in anodic oxide films on aluminum and Al5052 alloy during electroless-plating. Pure aluminum and Al5052 alloy specimens were anodized in a sulfuric acid solution to form porous oxide films, and then immersed in boiling water to seal the pores. Confocal scanning laser microscopy was applied to examine the effect of pore-sealing on the Ni-P electroless deposition through imperfections. There were Ni-P domes deposited on both pure aluminum and Al5052 alloy covered with anodic oxide films through the imperfections in the oxide film. The number of Ni-P domes increased with electroless plating time on both kinds of specimens, and this change was more remarkable on Al5052 alloy, due to imperfections originating from second phase particles in the alloy substrate. Sealing treatment effectively prevented Ni-P dome deposition on both types of specimens, due to healing of the imperfections in the oxide films. Longer anodizing before the sealing treatment prevented the Ni-P deposition completely on the Al5052 alloy specimen even after 15 h of electroless plating.
