Investigation of process parameters for quality deposition of AL5356 using cold metal transfer wire arc additive manufacturing (CMT-WAAM)

This research investigates mechanical properties, microstructure, and optimal parameter values for wall deposition utilizing the response surface Method. The printed structures were evaluated using microhardness tests in the deposition directions, Charpy impact, and tensile testing at room temperature. The tensile test results revealed that the central layers had a maximum yield strength of 191 MPa, an ultimate tensile strength of 321 MPa, and an elongation of 16.03%. The hardness assessment by Charpy testing yields a maximum value of 23.57 J for the core layer. The top layer has a greater hardness (65.73Hv) than the remainder of the sample. The effects of SOD, TS, and WFR on BW, BH, and AR were assessed after the parameters were optimized. The variation is caused by the heat from subsequent layers reheating the previous ones, causing grains to become larger. Grain coarsening happens due to prolonged heat exposure, reducing hardness and increasing ductility. Grains may demonstrate equiaxed development near the fusion zone before transitioning to columnar growth along the deposition direction. Stress is released when the bottom layers are warmed repeatedly. The middle section receives light warmth but still undergoes grain refinement due to controlled cooling. The material may feature elongated columnar grains along the build direction and finer subsequent phases. Mechanical properties like impact toughness and ductility often find their optimal balance in this region. The top layers cool faster because they do not store heat like the lower levels. Grain refinement occurs due to rapid solidification, increasing hardness while lowering toughness. Because the top layers do not experience warming cycles, residual tensions are higher, potentially leading to deformation or breakage. The heat gradient forces the grains to rise vertically, forming columnar structures. The replies indicate that the best parameters for single-layer deposition are a Wire Feed Rate (WFR) of 7 mm/min, a standoff distance (SOD) of 20 mm, and a travel speed (TS) of 20 cm/min. Wire arc additive manufacturing (WAAM) characteristics were evaluated using statistical approaches, such as analysis of variance (ANOVA) and the desirability function.