무전해 니켈 도금된 선박 디젤엔진 실린더 라이너의 캐비테이션 침식 특성 = Cavitation Erosion Characteristics of Electroless Nickel-Plated Marine Diesel Engine Cylinder Liner

다국어 초록 (Multilingual Abstract)

This study assessed the enhancement of cavitation erosion resistance in gray cast iron, a common material used for marine diesel engine cylinder liners, through the application of electroless nickel plating (ENP). EDS and XRD analyses revealed that the ENP coating contained approximately 6.4 wt% phosphorus and displayed broadened Ni diffraction peaks, suggesting an amorphous or microcrystalline structure. Cavitation erosion tests were performed following ASTM G32 standards using an ultrasonic vibratory apparatus set to an amplitude of 50 μm. The gray cast iron substrate exhibited a rapid increase in cumulative weight loss with exposure time, reaching about 1.2 mg after 90 minutes, along with a significant rise in surface roughness and maximum damage depth. In contrast, the ENP-coated specimen showed a much slower rate of material loss, with cumulative weight loss limited to approximately 0.4 mg even after 240 minutes. Three-dimensional surface profiling further confirmed that the ENP coating effectively inhibited the growth and coalescence of erosion pits, resulting in lower surface roughness and shallower damage depth compared to the substrate. These findings indicate that ENP is an effective surface treatment for improving the cavitation erosion resistance and durability of marine diesel engine cylinder liners in coolant environments.