Experimental investigation on optimizing cavitation erosion resistance of ductile iron via hundred-micron array groove structures

Abstract Drawing on the excellent anti-erosion characteristics of non-smooth biological surfaces, laser processing was employed in this study to fabricate array groove structures on the surface of ductile iron, and its cavitation resistance was investigated in engine coolant. Within the hundred-micron scale, the results show that samples with a groove width-to-spacing ratio L / W of 0.5 and 1 exhibited greater cavitation resistance than conventional polished samples. Notably, sample with L = 200 μ m and W =200 μ m ( L / W = 1) exhibited optimal anti-cavitation performance, which had a significant 42.0% reduction in cumulative mass loss and nearly twice the anti-cavitation performance relative to the polished sample. Furthermore, an evaluation model was established by introducing a new dimensionless service performance parameter G s . Based on the model analysis, the anti-cavitation mechanism of grooved structures did not merely prolong the incubation period. It significantly slowed down the damage progression during the acceleration period and mitigated long-term cumulative erosion damage during the decay period, thereby achieving full-life cavitation protection. This study provides a valuable reference for the design of cavitation-resistant surface structures in engineering.