Development of Cavitation Erosion–Resistant Microwave Processed WC-based Cladding

Abstract

In the present work, we investigated the effectiveness of microwave processing and thermal spraying for developing tungsten carbide (WC)-based erosion-resistant claddings. The microwave cladding showed a columnar structure with a well-bonded interface compared to discrete splat morphology and discontinuous interface of the thermal spray coating. The cladding showed a lower hardness (800 HV) compared to thermal spray coating (1,300 HV) and a two times higher fracture toughness due to the absence of splat boundaries and pores. The microwave cladding also showed 14 times and 10 times higher cavitation erosion resistance than thermal spray coating and SS316L substrate steel, respectively. The improved cavitation erosion resistance of the microwave cladding is explained on the basis of the optimized combination of hardness and fracture toughness. The surface of eroded cladding showed plastically deformed micropits compared to the thermal spray coatings, which showed large craters. Results show that microwave claddings can help improve the durability of engineering systems.

Keywords:

• Microwave cladding
• cavitation erosion
• thermal spraying
• tungsten carbide
• D-gun