Magnetic disk substrate of titanium.

摘要

A magnetic disk substrate comprising a main body made of titanium or a titanium allow, and an anodized film formed on the main body. The ratio of the color difference existing on the surface of the anodized film to the voltage applied to the main body to form the anodized film is at least 0.35. The color difference defined in L*A*b* color system as ¦ L*MAX-L*MIN ¦ + ¦ a*MAX-a*MIN ¦ + ¦ b*MAX-b*MIN ¦, where MAX and MIN are the maximum and minimum values L*, a* and b* have. <IMAGE>