To provide an aluminum die-cast material with a higher corrosion resistance and a method for manufacturing it and various applications of them, which can obtain a dense boehmite film with a low porosity rate and a high adhesion, and at the same time, can form a layer on the surface of the die-cast material, in which an Al-Si eutectic structure inferior in the corrosion resistance is reduced.
The aluminum die-cast material with high corrosion resistance comprises, sequentially from the outer surface, a hydrous oxide layer of Al, an oxide film with a porosity rate of 30% or less by volume, which is mainly composed of an aluminum oxide including divalent metals, a hardened layer of a base metal, an Al rich layer, and so on. The surface treatment method comprises grinding the material with a machine, and treating it in a hot water including divalent metals. The product is particularly used for a fully automatic washing machine and its flange, and for reagent-retaining containers for an immunity analyzer and a blood analyzer.
OHASHI TAKEYA
FURUKAWA YOSHINORI
UKO KENJI
HOSHI EIJI
