Experimental investigation of cavitation erosion mechanisms and performance in microwave-cladded NiCrSiC-5Mo composites

Abstract

Cavitation causes rapid surface degradation, material loss, and reduced service life in propellers and other marine components, making it a critical operational challenge. AISI 420 stainless steel, commonly used in small vessel propellers and industrial equipment, is especially vulnerable under such conditions. In this work, the wear resistance of AISI 420 was improved by applying a microwave-processed composite cladding. Nickel powder reinforced with molybdenum was deposited onto the steel surface using microwave hybrid heating, a process that provides uniform heating and strong metallurgical bonding. The clads were studied using SEM/EDS and XRD, and their porosity and hardness were carefully measured. The treated surface showed nearly double the hardness compared to the base metal, increasing from about 310 ± 20 HV for the substrate to 591.53 ± 20 HV after cladding. Cavitation tests using a vibratory erosion setup confirmed that this improvement translated into better real-world performance. The reinforced cladding significantly improved cavitation erosion resistance, reducing the erosion rate to 16.1%, a threefold improvement over the untreated clad (49.43%). SEM analysis of the eroded surfaces revealed characteristic damage features, including pits, craters, micro-cracks, and plastic deformation, and confirmed that reinforcement induced a transition from ductile to brittle wear behavior.