Investigation of the overlapping parameters of MPAW-based rapid prototyping

Purpose - To fabricate fully dense components with low costs, a rapid prototyping (RP) system based on micro-plasma arc welding (MPAW) was developed. The appropriate process parameters were investigated to build the parts with good mechanical properties and surface smoothness. Design/methodology/approach - A simplified overlapping model between deposited tracks was established to investigate the relationships among the overlapping parameters, such as the ratio of width to height of the deposited track cross-section (λ), scan spacing and overlapping ratio. Some ER308L stainless steel parts were built by different overlapping parameters, and the surface smoothness, tensile strength and elongation of the parts were tested. Findings - The overlapped surface smoothness, tensile strength and elongation of the parts built with larger λ were better than those built with smaller λ. The longitudinal tensile strength and elongation of the parts were better than the transverse data. Research limitations/implications - The scanning direction obviously affected the tensile strength and elongation of the parts, so the multi-directional scanning mode should be used to get isotropic parts. Originality/value - This MPAW-based RP system provides a solution to build fully dense metal parts with relatively lower costs. The appropriate process parameters can be obtained with the developed overlapping model.