Process optimisation of cold spray Al coating on AZ91 alloy

Abstract

Cold spray technology continues to attract increasing attention in surface modification of light metals due to its low temperature operation. A method for selecting optimum process parameters is presented for cold spraying of aluminium coatings upon magnesium alloy AZ91. In the present study, particle deposition behaviour is investigated via modifying spraying parameters. Subsequently, based on the relationship between bonding ratio and particle velocity, the critical particle velocity for successful adhesion is determined. Finally, the influence of particle velocity on key coating characteristics is examined, including coating porosity, hardness, deposition efficiency and bond strength.

Keywords:

• Magnesium
• Aluminium
• Coating
• Spray
• Optimisation

Acknowledgements

The authors are grateful to the CAST CRC and Australian Research Council (ARC) Centre of Excellence for Design in Light Metals for support. Thanks to Mr A. Allirand from ENISE, France, for his technical assistance during his internship at UQ.