Thermal modeling of geometry of single-track deposition in micro-plasma transferred arc deposition process

Abstract

Micro-plasma transferred arc (μ-PTA) deposition process is a recently developed material and energy efficient additive layer manufacturing process for metallic deposition which is capable of bridging the gap between capabilities of high energy based and conventional arc-based deposition processes. Development of model of deposition geometry is essential to study the relationship and influence of various process parameters on the deposition geometry parameters. This paper reports development of a thermal model to predict single track deposition width and height in terms of three important process parameters of μ-PTA deposition process (i.e. input power, volumetric deposition rate and travel speed of worktable) using fundamental principles of energy balance and heat transfer. The developed model was validated by comparing the model predicted results with the experimental results of single track deposition geometries corresponding to various parametric combinations in the μ-PTA deposition process. The predicted values were found in very good agreement with the experimental results thus validating the developed models. The developed model has wide applicability because it depends only on thermal properties of the substrate and deposition materials and is independent of form of the deposition material therefore it can be used for predicting deposition geometry for any combination of substrate and deposition materials and for any form of the deposition material.