| 摘要 |
<p>The molten alloy, based on Zn or Sn and containing one or more of Ti, Mn, V, Nb, Zr, Th, mischmetal, Cd, AsCu, Pb or Cr, or for Zn alloys up to 0.002% Al, is exposed to a free oxygen containing atmosphere, the amount of additive, the temp. of the melt and exposure time being so selected that a film of an oxide of the minor constituent is formed which is thick enough to form interference colours when it is illuminated. The alloy may be in the form of a coating on a substrate (e.g. iron or steel) and may have been formed by spraying or hot dipping.</p> |
