| Abstract Scope |
Layer-wise laser surface cladding (LSC) of Rockit®401 on Al 1100 substrate was carried out by direct energy deposition method using 6-kW continuous wave fiber-coupled diode laser. Parametric optimization produced homogeneous, consistent clads without delamination/marked-brittleness, despite challenges with precipitation of brittle Fe-aluminides during LSC of ferrous alloy powders over Aluminum. X-ray diffractograms revealed presence of retained austenite, ferrite, martensite, Cr0.7Fe0.3 and similar solid solution phases but no Fe-Al intermetallic compound. Microstructures contained directionally solidified dendrites with multi-phase eutectic aggregate (hard solid solution and interstitial compounds) in inter-dendritic regions, characteristic of pure Rockit® clad. Average microhardness of clads varied from 450–500 HV0.1. Mechanical properties on the surface like hardness, wear resistance, elastic modulus/stiffness, and flexural strength under tension improved with vertical layering, due to lower Al dissolution from substrate. Hence, by establishing very specific LSC process window, LSC of Rockit® on Al 1100 is possible to improve wear resistance of Al-alloys. |