Thermo-Mechanical Modelling of Wire-Arc Additive Manufacturing (WAAM) of Semi-Finished Products

Abstract

Additive manufacturing processes have been investigated for some years, and are commonly used industrially in the field of plastics for small- and medium-sized series. The use of metallic deposition material has been intensively studied on the laboratory scale, but the numerical prediction is not yet state of the art. This paper examines numerical approaches for predicting temperature fields, distortions, and mechanical properties using the Finite Element (FE) software MSC Marc. For process mapping, the filler materials G4Si1 (1.5130) for steel, and AZ31 for magnesium, were first characterized in terms of thermo-physical and thermo-mechanical properties with process-relevant cast microstructure. These material parameters are necessary for a detailed thermo-mechanical coupled Finite Element Method (FEM). The focus of the investigations was on the numerical analysis of the influence of the wire feed (2.5–5.0 m/min) and the weld path orientation (unidirectional or continuous) on the temperature evolution for multi-layered walls of miscellaneous materials. For the calibration of the numerical model, the real welding experiments were carried out using the gas-metal arc-welding process—cold metal transfer (CMT) technology. A uniform wall geometry can be produced with a continuous welding path, because a more homogeneous temperature distribution results.

Balancing WAAM Production Costs and Wall Surface Quality through Parameter Selection: A Case Study of an Al-Mg5 Alloy Multilayer-Non-Oscillated Single Pass Wall

“…Each printed wall consisted of 15 layers on the substrate, which was made from commercially-pure aluminum bars (190 mm × 50 mm × 6 mm). Each layer was deposited in an inverse direction, i.e., bi-directionally, to maintain higher uniformity of the wall dimensions at both wall ends, as already demonstrated in the literature (for instance, by Graf et al [17]). Substrate bucking and uneven heat concentration during the deposition would interfere in the layer formation, impairing the comparisons.…”

Advanced computational modelling of metallic wire-arc additive manufacturing

“…4. FE model with the mesh -base plate 32.000 FEs, each la e 32.000 FEs, each lay yer 15.000 FEs er 15.000 FEs Temperature-dependent physical properties of welding wire (G3Si1), used in numerical computation, are taken from [2] because of the similarity in the chemical composition of G3Si1 and G4Si1 material, used in [2]. Same properties were used for the base plate.…”

“…Because the process itself involves thermo-mechanically complex phenomena, Finite Element-based virtual models are commonly employed to optimize the process parameters [1]. The finite elements (FEs) activation is applied in numerical investigations of deposition of a welding wire, where the melting temperature is employed as the activation criterion [2]. There are two procedures available for dealing with inactivating FEs in the FE numerical model [3].…”

Study on the thermal cycle of Wire Arc Additive Manufactured (WAAM) carbon steel wall using numerical simulation

“…2(a). These parameters were determined from results reported by Nuraini et al [13] Table 2: The values for heat source parameters [13] The heat source model considers the heat flux losses by convection and radiation; thus, during the FE analysis, a convection heat transfer coefficient of 35 W/m 2 K, the radiative emissivity of 0.5, and the Stefan-Boltzmann constant of 5.67x10 -8 W m -2 K -4 were used for the external sides of the substrate and layers [14]. The parameters for heat loss were not applied to the longitudinal mid-plane because of the symmetry thermal boundary.…”