Aluminium composite coatings produced by plasma transferred arc surfacing technique

Abstract Plasma transferred arc surfacing (PTA) is a hardfacing technique by which a coating is deposited on to a substrate by the injection of metal powder and/or ceramic particles into a weld pool. Establishment of a plasma column initiates this weld pool formation. Few studies have been published on the use of PTA in the surface modification of low density substrates such as aluminium or titanium alloys. In the present work, the deposition of metal matrix composite (MMC) coatings on to aluminium 5083 alloy substrates has been achieved. The experimental process involved the codeposition of an aluminium-nickel (Al2 wt-%Ni) powder containing various ceramics (Al2O3, SiC, and TiC) with discontinuous particulate morphology. Composite coatings of varying reinforcement volume fractions Vf (0–40%) and particulate sizes (70–140 μm) have been fabricated. The first part of the research involved optimisation of the PTA parameters. The second part concentrated on characterising the features of the coatings. Two mai...