Effect of HIP Treatment on Microstructure and Fatigue Strength of Selectively Laser Melted AlSi10Mg

Wolfgang Schneller, Martin Leitner, Sebastian Springer, Florian Grün, Michael Taschauer

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25 Citations (Scopus)

Abstract

This study shows the effect of hot isostatic pressing (HIP) on the porosity and the microstructure, as well as the corresponding fatigue strength of selectively-laser-melted (SLM) AlSi10Mg structures. To eliminate the influence of the as-built surface, all specimens are machined and exhibit a polished surface. To highlight the effect of the HIP treatment, the HIP specimens are compared to a test series without any post-treatment. The fatigue characteristic is evaluated by tension-compression high cycle fatigue tests under a load stress ratio of R = −1. The influence of HIP on the microstructural characteristics is investigated by utilizing scanning electron microscopy of micrographs of selected samples. In order to study the failure mechanism and the fatigue crack origin, a fracture surface analysis is carried out. It is found that, due to the HIP process and subsequent annealing, there is a beneficial effect on the microstructure regarding the fatigue crack propagation, such as Fe-rich precipitates and silicon agglomerations. This leads, combined with a significant reduction of global porosity and a decrease of micro pore sizes, to an improved fatigue resistance for the HIPed condition compared to the other test series within this study.
Original languageEnglish
Article number16
Number of pages9
JournalJournal of Manufacturing and Materials Processing
Volume3.2019
Issue number1
DOIs
Publication statusPublished - 1 Feb 2019

Keywords

  • Additive manufacturing
  • AlSi10Mg
  • Fatigue strength
  • HIP
  • Porosity
  • SLM

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