The authoritative public forum
  for Metal Finishing since 1989
  

  -----

Can chrome be applied via metallizing flame spray

A pump repair facility has explained to me that they were "metal spraying" a chrome finish on our pump shaft bearing journals. I have never heard of this method of application for a chrome finish. Any advise?

Lynn Warner
- Sayreville, New Jersey
2002

No, at least in a commercial way. May be in high tech applications or for experimental use. The closest material commercially thermosprayed would probably be chrome carbide or chrome oxide(known as ceramics or hardfaces). Another possibility is they are spraying a high chrome stainless steel with around 25% Cr rest Iron, or a high nickel-chrome SS alloy. But the most important thing to comment is the differences between the spraying and the chrome plating processes. The first achieves only mechanical bond to substrate while the plated chrome is metallurgically bonded. Also, sprayed materials are more porous but with the proper sealing and the new high impact spray guns available both can be equaled. On the other hand, spraying offers far more versatility to adapt to environment and function than chrome plating.

Guillermo Marrufo
Monterrey, NL, Mexico
2002