Thermal analysis for single-pass multi-layer GMAW based additive manufacturing using infrared thermography

An infrared camera after calibration test was used to capture the surface temperature of the deposited thin-wall parts for investigating the thermal behavior of gas metal arc welding (GMAW) based additive manufacturing (AM). The temperature field cloud pictures indicated that as the deposition height increased, the heat accumulation of the deposited parts became serious. Through extending the inter-layer cooling time, the high temperature area and the mean temperature of the thin-wall part decreased while the temperature gradient and cooling rate of the deposited part increased. But excessive inter-layer cooling time cannot reduce heat accumulation of the deposited parts effectively and will make the deposition process time-consuming. The comparison of the final parts in forming appearance with different inter-layer cooling time indicated that the moderate prolongation of inter-layer cooling time contributed to improvement of the surface quality and reduction of the total height difference. Using the alternate inter-layer cooling time can improve the forming quality of the thin-wall part distinctly with a little increase of the deposition time in GMAW based AM.