Microwave cladding of NiCrSiC-5Al 2 O 3 on austenitic stainless steel to improve cavitation erosion resistance

Abstract The current investigation aimed to study the cavitation erosion performance of the microwave synthesized NiCrSiC-5Al 2 O 3 composite clad with a 900 W power multimode domestic microwave applicator of 2.45 GHz frequency. The clads were deposited on the austenitic grade stainless steel, namely AISI-316. The as-deposited composite clad’s microstructure, crystal structure, porosity, microhardness, and flexural strength were examined. Cavitation erosion study was done using the vibratory cavitation method at varying standoff distance (SOD)-(0.5 mm, 1 mm, 1.5 mm) and vibration amplitude (AMP)-(40 μ m, 50 μ m, 60 μ m), keeping other parameters constant. The results had shown that the deposited NiCrSiC-5Al 2 O 3 composite clad exhibited 1.20% porosity, 489.16 ± 47.95 HV 0.3 microhardness, 264.91 ± 4.5 MPa flexural strength, and performed 3.5 times much better than the AISI-316 in terms of cavitation resistance. The least weight loss occurred at 1.5 mm SOD and 40 μ m AMP, where the highest weight loss was observed at 0.5 mm SOD and 60 μ m AMP. The erosion mechanism of the NiCrSiC-5Al 2 O 3 composite clad surface was observed as plastic deformation followed by surface fatigue; the clad surface was eroded in the form of pits, craters, impingement marks, secondary cracks, and plastically deformed lips.