|About this Abstract
||2019 TMS Annual Meeting & Exhibition
||Additive Manufacturing of Metals: Fatigue and Fracture III
||Fracture Toughness and Fatigue Strength of Selective Laser Melted Aluminium-Silicon: An Overview
||Leonhard Hitzler, Enes Sert, Markus Merkel, Andreas Öchsner, Ewald Werner
|On-Site Speaker (Planned)
In selective laser melted aluminium-silicon alloys, the high cooling rates lead to an increased (non-equilibrium) solubility of Si in α-Al and consolidates in a cellular structure starting from the melt pool boundaries. Correspondingly, the Si-content is inhomogeneous across a single scan track, with the Si-content decreasing from the scan track boundaries towards its center. Si-segregations occur in these oversaturated regions and this enrichment is further favoured in remolten areas. When left untreated, these Si-enrichments represent brittle areas and predetermined locations of fracture. Investigations reveal a noteworthy drop in static mechanical strength, attributed to shear fracture along the enrichment zones. A preliminary study shows that the directional dependency affects also fracture toughness. Crack propagation parallel to the layering, correspondingly in direction of the joined embrittlements, lowers the fracture toughness by around 20%. These results demonstrate the necessity to study fracture and fatigue properties and their susceptibility to changes with loading direction.
||Planned: Supplemental Proceedings volume