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PVD or CVD Deposition of Aluminum on Steel

What is the ideal substrate temperature, i.e., mild steel for depositing aluminium oxide and what is the % of oxygen required for Al2O3. When depositing for wear resistance what is the ideal thickness.

Brian Morgan
- Salford
 

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Aluminum oxide is generally deposited on carbide by chemical vapor deposition, with substrate temperatures on the order of 1100 °C. Success depositing it by PVD methods has been mixed, and I doubt that anyone has tried depositing it on mild steel. If you are certain that you need aluminum oxide, I would suggest that you look locally -- the University of Salford.

Jim Treglio - scwineryreview.com
PVD Consultant & Wine Lover - San Diego,
California
 

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As Jim said there probably isn't a lot of information out there about depositing Al2O3 on mild steel. With PVD Al2O3 can be deposited as low as 100C depending on the equipment used.

Make sure you take into consideration the heat treatment of the mild steel before you do the coating. If the temperature of the deposition is high enough you can anneal the steel while doing the coating. If the steel is hardened (i.e., martensitic) the steel with shrink as the martensite transforms to bcc iron and Fe3C. This shrinkage can cause your coating to pop off during deposition. This all can be avoided by choosing process parameters that avoid annealing but most people don't think of it the first time they do these coatings.

John Davis
- Berthoud, Colorado, USA