Synergistic strengthening of W–Cu composites with Y2O3 and Mo for enhanced arc ablation resistance

This study employed a synergistic approach combining Mo solid-solution in W and Y 2 O 3 addition to improve the arc ablation resistance of W–Cu composites. Both Mo and Y 2 O 3 effectively refined the W grain size in liquid-phase sintered composites, which enhanced the capillary forces within the W skeleton and improved the retention of molten Cu during arcing. Compared with conventional micron-sized W–Cu composite, the combined action of W particle refinement, Mo solid-solution strengthening, and Y 2 O 3 dispersion significantly suppressed localized arc erosion on the Cu phase. Notably, under high-temperature arc conditions, dissolved Mo further migrated into the Cu matrix, increasing the viscosity of the molten Cu and thereby reducing its extrusion and splattering. This mechanism helped retain more Cu in the ablation zone, promoting efficient arc-root cooling via transpiration. As a result, the W–Mo–Cu–Y 2 O 3 composite exhibited outstanding arc ablation resistance with the lowest ablation crater depth, area and volume of 32 μm, 2.100 mm 2 , and 0.083 mm 3 , respectively, owing to these synergistic effects. The findings offer valuable guidance for the design of advanced arc resistant composite materials.