Influence of multiple scan fields on the processing of 316L stainless steel using laser powder bed fusion

Abstract

The sharp growth that additive manufacturing has been showing recently has broadened its application field and resulted in more varied demand of high-volume parts as well as a general increase in part series. The current focus on productivity enhancement of additive manufacturing has imposed the implementation of multiple-laser systems with larger scan fields. Its usage, combined with adequate layer thickness and laser power selection, makes high-volume parts less challenging to obtain. This paper focuses on understanding the influence of using multiple-scan fields for the fabrication of large components, especially on the parts region corresponding to scan field interface. The microstructure as well as mechanical behaviour of the multi-field manufactured samples are compared with parts fabricated using a single-field, for distinct processing parameters. Moreover, given the unreliability of additive manufacturing regarding dimensional and geometrical tolerances with increasing build rates, post-processing metal-cutting operations were studied towards additive manufacturing process hybridization. Despite the typical additive manufacturing process variability, a set of parameters, within testing conditions, could be identified as the most appropriate solution towards mechanical strength enhancement. Nonetheless, porosity levels can significantly impact the ductility of parts, which may be additionally compromised by its occurrence in the scan-field interface region.

Numerical-Experimental Plastic-Damage Characterisation of Additively Manufactured 18Ni300 Maraging Steel by Means of Multiaxial Double-Notched Specimens

“…A lower repeatability within the AMed samples is observed. This may be explained by the existence of internal defects in the AMed steels, which can compromise their mechanical behaviour, especially their ductility [40,41]. It is also important to consider the relative size effect of those defects when analysing small material samples, as might have been the case for the tested tensile geometries.…”

Modelling the asymmetric tension–compression properties of additively manufactured alloys using continuum damage mechanics

“…Prediction of the mechanical behaviour of additively manufactured alloys under different loading conditions is a substantial step to optimise their performance in complex service environments. 26 Axisymmetric and 3D models were used for the samples under uniaxial tension and compression tests. Axisymmetric CAX4R and C3D8R elements in 3D FEM analysis were used for this study.…”

An Efficient Methodology towards Mechanical Characterization and Modelling of 18Ni300 AMed Steel in Extreme Loading and Temperature Conditions for Metal Cutting Applications

“…For example, Marbury et al [12] reported tool breakage when applying standard cutting parameters thought for conventionally manufactured (CMed) 316 L stainless steel, on the AMed counterpart. On the same alloy, Leça et al [13] have shown that porosity directly influences the cutting loads and reported a relationship between chip segmentation and relative density. Focusing on the effect of cutting velocity, Bai et al [14] have compared the machinability of the AMed A131 steel with its conventional counterpart, focusing on the effect of cutting speed.…”