Pitting resistant carbon coatings
A hydrogenated diamond-like coating (“H-DLC”) for metallic substrates provides improved reliability. The H-DLC is relatively soft and elastic. Unlike hard and/or inelastic coatings in the prior art, the present coatings do not exhibit a loss of adhesion (delamination). A bonding layer may be used between the metallic substrate and the H-DLC. H-DLC coatings can, for example, be used in bearings and gears to reduce the occurrence of micropits and, ultimately, product failure.
1. An article of manufacture comprising:
a steel substrate;
a metallic bonding layer on the steel substrate;
a carbide bonding layer deposited the metallic bonding layer; and
a tribolayer comprising amorphous hydrogenated diamond-like coating comprising sp2 and sp3 bonded carbon atoms deposited on the carbide bonding layer;
wherein the tribolayer has a hardness of 2-7 GPa and an elasticity of equal to or less than 60 GPa.
2. The article of manufacture of claim 1 , wherein the hydrogenated diamond-like coating has between 30% to 60% bonded or unbonded hydrogen.
3. The article of manufacture of claim 1 , wherein the steel substrate is a rolling element.
4. The article of manufacture of claim 1 , wherein the steel substrate is a track member.
5. The article of manufacture of claim 1 , wherein the tribolayer hardness is 5-6 GPa and an elasticity of between 50 GPa and 60 GPa.
6. An article of manufacture comprising:
a metallic substrate;
a chromium bonding layer on the metallic substrate;
a carbide bonding layer deposited the chromium bonding layer;
a hydrogenated diamond-like coating deposited on the carbide bonding layer, the hydrogenated diamond-like coating having between 30% and 60% bonded or unbonded hydrogen;
a steel substrate in contact with the hydrogenated diamond-like coating; and having a tribolayer comprising an amorphous hydrogenated diamond-like coating comprising sp2 and sp3 bonded carbon atoms;
wherein the hydrogenated diamond-like coating has a hardness of 2-7 GPa and an elasticity of equal to or less than 60 GPa.
7. The article of manufacture of claim 6 , wherein the metallic substrate is a rolling element.
8. The article of manufacture of claim 6 , wherein the metallic substrate is a track member.
9. The article of manufacture of claim 6 , wherein the tribolayer hardness is 5-6 GPa and an elasticity of between 50 GPa and 60 GPa.
10. The article of manufacture of claim 6 , wherein the hydrogenated diamond-like coating has a thickness of 0.1 to 10 um.