| 摘要 |
PURPOSE:To form a black film on the surface of Al or an Al alloy by chemically plating the metal with an alkaline aq. soln. contg. Zn and by treating it with an acidic aq. soln. contg. ions of a specified metal. CONSTITUTION:Al or an Al alloy is pickled and washed to clean the surface and the cleaned surface is chemically plated with Zn by immersion in an alkaline aq. soln. of >12 pH contg. 1-30g/l Zn ions at 10-50 deg.C for 15sec-5min. After the plated surface is washed, surface treatment is carried out with an acidic aq. soln. contg. 0.1-20g/l ions of a metal such as Sn, Cu, Pb or Ag, especially Cu or Ag in the form of sulfate, nitrate, chloride or the like. The temp. of the soln. is 10-60 deg.C and the treatment time is 5sec-5min. An ornamental black film having depth in color is formed. |
