Thermal Spray Powder Coatings for Resistance to Erosion

The selection of coating for erosive wear is dependant on the severity and type of erosion. For solid impingement erosion at a shallow angle of attack where the wear is similar to that of abrasion, high hardness coatings are required. For solid impingement angles near 90 coating toughness becomes more important. For cavitation and liquid impingement generally, a coating with good surface fatigue resistance is needed. The following coatings are commonly used:

• Cermet coatings like tungsten carbide/cobalt
• Chromium carbide/nickel chromium (particularly for high temperatures above 540 C)
• Fused self fluxing alloys
• Non ferrous alloys, aluminium bronze, monel
• Oxide ceramics like chromium oxide and alumina
• Various alloys of iron, nickel, chromium or cobalt