Overview of metallurgical studies on weld deposited surface by plasma transferred arc technique

Research on plasma transferred arc (PTA) coatings has increased contemplation due to its augmented appropriateness which results from the advanced materials used in applications like mining, petroleum and power plant sectors. This article further broadens the research scope of investigation, by influencing metallurgical and processing aspects in accordance with the significance of microstructural changes. Martensitic formation with coarser structure, carbide phase formation and fine interdendritic eutectic matrix are the significant metallurgical aspects for an improved surface characteristic. Welding current, powder feed rate and travel speed, are the significant processing variables to achieve the microstructural changes like uniform dendritic growth, finer grain size, etc. The addition of alloying elements and heat treatment are the most observed processing conditions for the formation of precipitates and carbide phases. A schematic summary, the significance of processing variables, processing conditions and process modelling and simulation on metallurgical aspects have been enumerated in this paper. Further, critical comments and findings from in-depth review have also been discussed for the future scope. Hence, this review will be helpful to ascertain the relation among the microstructural evolution, the applicability of microscopic tools and the mechanical properties for the forthcoming researchers and the industrial persons.