Comprehensive analysis of spatter loss in wet FCAW considering interactions of bubbles, droplets and arc – Part 2: Visualization & mechanisms

•Spatter generation mechanisms were investigated via visually sensing the complex interactions between droplets, bubbles, arc and water.•Bubble evolution, arc behaviors, and droplet transfer jointly caused the generation of typical explosive and repulsive spatters.•High-temperature liquid droplet might change into spatters when significantly affected by the bubble necking location and timing.