Influence of TiC particles on the properties of AA2017 friction surfaced coatings

Abstract

Friction surfacing (FS) is a solid-state process employed for coatings that has demonstrated significant advancements in the manufacturing of aluminium matrix composites reinforced with ceramic particles. This study explores the effect of AA2017 aluminium consumable rods packed with titanium carbide (TiC) in the FS process applied to an AA6082 substrate. A subsequent post-processing friction stir process (FSP) was performed to further refine the distribution of ceramic particles. Analyses were conducted using light optical and scanning electron microscopy, X-ray diffractometer (XRD), microhardness, and pin-on-flat wear testing. The results demonstrated that the incorporation of TiC reinforcement significantly enhanced the FS deposition efficiency and rate by approximately 31%, without affecting rod consumption. Initially, the TiC particles were distributed in layers parallel to the substrate surface, but the FSP technique dispersed them throughout the aluminium matrix. In terms of mechanical properties, the reinforcement increased microhardness by 13.6% and reduced wear resistance (wear volume) by 13%. Notably, the FSP process enhanced wear resistance, reducing wear volume by 48% compared to the TiC-free coating, while also mitigating the hardness increase caused by the FS process. Additionally, XRD analysis indicated that neither FS nor FSP generated new phases, indicating no interaction between the aluminium matrix and the ceramic reinforcements.