The specular gloss and crystal structure orientation of electro-deposited chromium have been studied for deposits prepared at current densities from 10 to 110 A/dm², and temperatures from 20 to 70°C, using three kinds of chromic acid baths.
a) CrO₃ 250 g/l, H₂SO₄ 2.5 g/l b) CrO₃ 250 g/l, H₂SO₄ 1.0 g/l, Na₂SiF₆ 2.5 g/l c) CrO₃ 600 g/l, H₂SO₄ 3.8 g/l, Sugar 10 g/l
The brightest deposits are characterized by a (111) prefered orientation as had been shown by Yoshida or Hume-Rothery and Wyllie. Diagrams have been constructed showing the effect of temperature and current density on the values of the specular gloss and crystal orientation of the deposit.
In addition to a well known (111) orientation, a (110) and a special (111) orientations are found at higher temperature.