Analysis of the influence of L-PBF porosity on the mechanical behavior of AlSi10Mg by XRCT-based FEM

Abstract

This work aims to present an XRCT-based FEM methodology to assess the influence of porosity defects on the mechanical behavior and failure of L-PBF AlSi10Mg components. Hence, the influence of defects on performance is estimated by means of XRCT scanning and analysis of porosity features, followed by mechanical FEM modelling of digitalized components. For this purpose, some test specimens with induced artificial porosity were manufactured by L-PBF, according to ASTM E8/E8M. Once this is done, inspection and defect characterization were carried out by means of XRCT. Porosity features such as void size, shape and location, apart from porosity percentage, were analyzed. Then, tensile tests were carried out, followed by further inspections by XRCT in order to research the relationship between the fracture level and the porosity of the as-built sample. Afterwards, virtual tensile tests of XRCT-ed specimens were modeled by FEM technique. Results obtained by the FEM model were well-correlated with the tensile experimental results to predict both ultimate tensile strength and elongation at fracture of each specimen, showing errors below 5.2%. However, the results of the final fracture level predicted by FEM analysis reveal that possibly underestimated and/or non-detected defects on the AlSi10Mg specimens seem to influence the accuracy of the fracture level prediction in some samples. Thus, XRCT arises as an ideal technology for the assessment of L-PBF-ed components.

Keywords

• X-ray computerized tomography
• Porosity
• Laser-powder bed fusion
• AlSi10Mg
• Mechanical behavior
• Finite element modeling