Black Oxide for Investment Castings

Black oxide is used to provide a protective, corrosion resistant coating over metal. It has a uniform black finish that does not alter the dimensions of the part after casting. The coating does not chip or peel and acts as an absorbent to hold oils or wax.

Black oxide coatings are used on investment castings where a uniform black surface is desired. The coating is economical and offers a variety of valuable properties to extend the service life and improve the performance characteristics of a component. There is no dimensional change when using this surface coating.

Black Oxide for Investment Castings

So, as one kinds of surface coatings of investment castings, black oxide coating treatment is widely applied. Such surface treatment can help to get an anti-rust layer to increase the lifetime and release the stess of the castings caused during hardening process. After black oxide, we can achieve smooth and glossy surface on investment castings.

Key Benefits of Black Oxide Coating

  • Very economical surface coating method.
  • Black oxide does not cause any dimensional change of investment castings.
  • Able to achieve better than 100 hours of salt spray to red rust with supplemental oil dip.

Kindly remind that such surface treatment way is not ideal for low carbon steel castings. Black oxide surface with defects will show piebaldness, light colour and red colour. In this case, investment castings will have to be reblack oxided again.

CFS offers a wide range of surface treatment or coating options (black oxide, zinc plating, painting, powder coating, pickling & passivation, etc). Pls contact us if you have black oxide or other surface treatment requirements. We will give you our best solutions with attractive