High-Solids Chromia Suspensions Optimized for Wear Resistant Coatings

Suspension-sprayed chromia coatings are known for their low as-sprayed surface roughness and superior microstructure. Therefore, they offer a great potential for wear application where a good portion of the coating production process is dedicated to surface finishing work. However, throughput and costs of lab-scale suspension plasma spray processes were limiting the use in industry.

This study shows competitive SPS chromia coatings from water-based suspension feedstock with a solid content of 80 weight%. The coatings were optimized for wear applications with high surface quality demands like anilox rollers, piston rods or gasket seating surfaces. As-sprayed surface roughness, coating hardness, porosity, coating adhesion, sliding and abrasion wear performance were analyzed and benchmarked against F4-type plasma sprayed coatings from conventional fused and crushed powder.