Thermal Spray Coatings for Improved Performance of Light Alloys

Purpose and goal

The aim was to study the feasibility of implementing advanced wear and corrosion resistant coatings produced by thermal spraying (TS) on light aluminium alloys. Three specific TS techniques wire arc spraying, high velocity air fuel (HVAF) spraying, and high velocity oxy fuel (HVOF) spraying were investigated using WC and Fe based materials. Apart from establishing process-coating material-performance correlations for these techniques through laboratory trials, a case study was performed on coated aluminium alloy in heavy exhaust fan blades used in mining industry.

Expected results and effects

The results showed that HVAF and HVOF sprayed coatings exhibited high performance but at higher costs as compared to wire arc sprayed coatings that provided a good lower cost alternative with satisfactory performance. The HVOF sprayed fan blades have performed well in field testing as compared to uncoated fan blades. The encouraging results from the project have also motivated other companies leading to a follow-up project being granted recently in the LIGHTer program, named CELIA, where Automotive Components Floby, Volvo Penta, Oerlikon Metco and TSE are the project partners.

Planned approach and implementation

Sliding wear testing, erosion testing, hardness testing and corrosion testing were performed on test coupons to understand the coating behaviour under different operating conditions and how they could improve the applicability of light alloys. The know-how and results generated from this project will be fruitful for further application of TS on light alloys for a variety of industrial applications and naturally contribute to the follow-up project. The project activities went well according to the plan.