US Patent 7429219 - nanocrystalline rust resistant coating for golf club head

http://www.freepatentsonline.com/7429219.html

This patent from Nelson Precision Casting teaches that nanostructured Fe-Co-Ni is particularly useful for protecting the rough surface of golf club heads from rust. Claim 1 reads:

1. A golf club head having a rust-resistant coating, comprising:

at least one club head component having a prepared surface; and

a rust-resistant coating layer forming on the prepared surface of the club head component, said rust-resistant coating layer made from a Fe—Co—Ni alloy including iron of 5-20 wt %, cobalt of 5-25 wt % and nickel of 60-90 wt %;

wherein said rust-resistant coating layer is formed with a nano-crystalline structure of the Fe—Co—Ni alloy.