A Novel Approach to the Elasto-Plastic Analysis of Residual Stresses for Layered Two-component Composite Coating Obtained by Hybrid Twin-Wire Arc Spraying

The distribution of residual stresses is a crucial factor in governing the performance of thermal-sprayed coatings. Even though this issue has been extensively investigated in previous reports involving homogeneous coatings, little progress has been made when it comes to composite coatings. Here, a novel type of elasto-plastic analytical model is proposed to study the residual stresses in a two-component composite coating prepared through thermal spraying process, in which the quenching stresses and thermal stresses are taken into consideration based on the assumption of layer-by-layer deposition. An arc-sprayed Fe-Al layered composite coating is applied as the model system for the case study. The results show that the distribution of residual stress in the Fe-Al two-component interlaced composite coating is quite different from that of a homogeneous thermal-sprayed coating. As the coating thickness increases, the difference becomes more significant. Benefiting from the improvement in residual stress distribution, it is confirmed by the analytical model and experimental investigation, that the two-component composite structure made of alternate layers of a hard steel and a soft aluminum can be used for forming thick coatings.