Abstract Scope |
Metal matrix composite coatings can improve the mechanical properties, wear, and corrosion resistance of steel in high-load-bearing applications such as railroads. In this work, cold spray (CS) technology is used to apply MMC coatings over steel for railroad repairs. While CS offers many advantages, such as minimal thermal input and dense coatings, it can also produce coatings with reduced ductility. Chromium carbide/nickel-chromium (CrC-NiCr) was cold-sprayed onto a steel substrate to investigate the effects of the matrix to ceramic ratio, the type of ceramic, and the post-process heat treatment on deposition efficiency, ceramic retention, strength, ductility, and durability. Results indicate that as the volume fraction of the ceramic particles increased, the deposition efficiency decreased but the overall mechanical properties improved. Additionally, post-spray annealing of the deposits enhanced ultimate tensile strength (UTS), elongation, and adhesion shear strength; however, it adversely affected the bulk hardness. |