blockodise process for metal blackening process blockodised coating

1. Blackodising process
(advantages, Applications)
By
Er. Rampal Singh Ojha

2. What is blackodising
• Chemical Blacking is sometimes referred to as ‘Blackening’ or
‘Blackodising’and is a conversion coating meaning that where in other
metal finishing processes a layer is added above the substrate, here a
coating is achieved through a chemical reaction between the ferrous
metal and the oxidising salts used in the black oxide coating.

3. Black oxide Process
• Blackodising Corrosion Resistance is a conversion coating formed by a
chemical reaction produced when parts are immersed in the alkaline
aqueous salt solution operated at approximately 135º C. The reaction
between the iron of the ferrous alloy and the hot oxide bath produces
a magnitite (Fe3 O4) on the actual surface of the part

4. Advantages of blackodising/blackoxide
• Minimal dimension change
• Aesthetic Finish
• No hydrogen brittlement
• Corrosion resistant
• Low cost

5. Applications
• his makes it a popular process for a number of components including:
Tool Parts, Jigs and Fixtures, Gears, Transmission Drives, Springs and
much more.