TY - JOUR

T1 - An improved process scan strategy to obtain high-performance fatigue properties for Scalmalloy®

AU - Schimbäck, David

AU - Mair, P.

AU - Kaserer, L.

AU - Perfler, L.

AU - Palm, F.

AU - Leichtfried, G.

AU - Pogatscher, Stefan

N1 - Publisher Copyright: © 2022 The Author(s)

PY - 2022/11/22

Y1 - 2022/11/22

N2 - The choice of appropriate processing parameters in laser powder bed fusion is firmly established in the state-of-the-art additive manufacturing community. However, optimisation of scanning strategy would result in improved material properties. Here, the optimal scanning strategy for fatigue-loaded high-performance aluminium alloys, such as Scalmalloy®, was investigated. This study demonstrates how to reduce uncontrolled interactions of the laser with the distinct weld plume, created by highly volatile alloying elements such as Mg. Tensile and fatigue testing were used to assess the structural integrity of specimens, in which different welding modes had been used. It is shown that a combination of: scan vector angle restriction; reduction of the scan vector length; and laser spot adjustments reduce the overall defect size and improves the build quality in Scalmalloy®. A bimodal microstructure with outstanding mechanical properties was observed: an ultimate tensile strength of 524 MPa was achieved with 17 % elongation at fracture. In order to evaluate the influence of the defect size, fatigue tests were performed at a stress ratio of . Under optimal processing conditions, fatigue strengths of up to at cycles were obtained, significantly outperforming both conventionally and additively produced aluminium alloys.

AB - The choice of appropriate processing parameters in laser powder bed fusion is firmly established in the state-of-the-art additive manufacturing community. However, optimisation of scanning strategy would result in improved material properties. Here, the optimal scanning strategy for fatigue-loaded high-performance aluminium alloys, such as Scalmalloy®, was investigated. This study demonstrates how to reduce uncontrolled interactions of the laser with the distinct weld plume, created by highly volatile alloying elements such as Mg. Tensile and fatigue testing were used to assess the structural integrity of specimens, in which different welding modes had been used. It is shown that a combination of: scan vector angle restriction; reduction of the scan vector length; and laser spot adjustments reduce the overall defect size and improves the build quality in Scalmalloy®. A bimodal microstructure with outstanding mechanical properties was observed: an ultimate tensile strength of 524 MPa was achieved with 17 % elongation at fracture. In order to evaluate the influence of the defect size, fatigue tests were performed at a stress ratio of . Under optimal processing conditions, fatigue strengths of up to at cycles were obtained, significantly outperforming both conventionally and additively produced aluminium alloys.

KW - Fatigue

KW - Laser Powder Bed Fusion

KW - Parameter Study

KW - Scalmalloy

KW - Welding Mode

UR - http://www.scopus.com/inward/record.url?scp=85142473833&partnerID=8YFLogxK

U2 - 10.1016/j.matdes.2022.111410

DO - 10.1016/j.matdes.2022.111410

M3 - Article

AN - SCOPUS:85142473833

VL - 224.2022

JO - Materials and Design

JF - Materials and Design

SN - 0264-1275

IS - December

M1 - 111410

ER -