Numerical investigation of erosion characteristics of multiple-particle impact on ductile material with patterned surfaces

Using Ti-6Al-4V alloy as the target substrate and rigid balls as the incident particles, we studied the anti-erosion behavior of the substrate with varying surface patterns collided by multiple particles with finite element method. The overlapping impact and secondary impact were considered in the model. The results reveal that the patterned surfaces may increase or decrease the mass loss, which is attributed to the combined effects of effective impact angle, overlapping impact and secondary impact. In particular, on curved surfaces, the impact coverage becomes highly non-uniform, leading to significant overlapping impact at certain areas, and secondary impact is also prone to occur. For overlapping impact, the accumulative mass loss arises from impacts at the lips caused by former impacts. The results also show that when the secondary impact lands at the damage zone caused by the primary impact, the material failure will be considerably worse.