Modelling erosion in surfaces of a ductile material impacted by irregular polyhedral particles

Resumo

In simulations of surface erosion, impacting particles have been systematically modeled as spheres. The use of other particle shapes, closer to reality, was the motivation for this work. In it, a non-linear finite element analysis was carried out in order to simulate, in 3D configuration, this type of erosion in surfaces of a ductile material. Impacts were done by rigid particles with irregular polyhedral, as well as with spherical and cubic shapes. Being a case of dynamic compression in an elastoplastic target material, involving effects of strain hardening, strain-rate and temperature, a Johnson and Cook formulation was used. Images from these simulations were compared to SEM images from previous experiments with a ductile material, the Duplex Stainless Steel UNS S32205, where their surfaces were eroded by impact of alumina particles entrained in air flux. Results of simulations were compared to those of experiments, considering the morphology, dimensions of erosion craters and evidence of mass loss. In simulations, results with irregular polyhedral particles reproduce the experimental ones better than those obtained with other shapes. Despite this, it was observed that simulations with spherical particles still remain useful. Additionally, simulations with polyhedral particles suggest further studies on a possible combination of two traditional models for erosion by impacting particles in ductile materials.