TY - JOUR

T1 - Mechanical behavior, microstructural evolution and texture analysis of AA2024-T351 processed by multi-layer friction surfacing with high build rates

AU - Hoffmann, Marius

AU - Roos, Arne

AU - Klusemann, Benjamin

N1 - Publisher Copyright: © The Author(s) 2025.

PY - 2025/9

Y1 - 2025/9

N2 - Solid-state additive manufacturing (AM) processes such as multi-layer friction surfacing (MLFS) can overcome typical disadvantages of fusion-based AM such as high residual stresses, porosity or hot cracking. The tool-less process setup of MLFS prevents contamination of the resulting components, e.g., caused by wear or the use of lubricants. The present study investigates MLFS for the precipitation-hardenable alloy AA2024-T3 using a process parameter that yields a high build rate relevant for industrial applications. The fatigue performance is shown and the microstructural and the mechanical anisotropy is examined. The fatigue properties in deposition direction show a high cycle fatigue limit of 170.5 MPa and a decrease in the maximum stress level compared to the base material due to precipitate overageing. The microstructure shows a Brass{011}⟨211⟩ texture at the bottom of the layers due to the application of high axial forces. In the center of the layer, no preferred texture was observed, while B{1¯12}⟨110⟩/B¯{11¯2¯}⟨1¯1¯0⟩ shear textures were observed at the top part of the deposited layers. An elongated grain morphology with aspect ratios above 2 is present over the entire layer height. These microstructural characteristics cause anisotropy in mechanical properties, with highest ultimate tensile strength and elongation in deposition direction, i.e., 408 ± 5 MPa and 18 ± 3 % respectively, and the lowest values along the build direction, i.e., 377 ± 21 MPa and 9 ± 3 % respectively. The observed behavior is of considerable importance for the industrial design and application of components manufactured with MLFS as they show that MLFS can also result in anisotropic material properties, depending on the chosen process parameters. It requires careful selection of the right combination of stud material and process parameters to achieve isotropic properties in the deposited structure.

AB - Solid-state additive manufacturing (AM) processes such as multi-layer friction surfacing (MLFS) can overcome typical disadvantages of fusion-based AM such as high residual stresses, porosity or hot cracking. The tool-less process setup of MLFS prevents contamination of the resulting components, e.g., caused by wear or the use of lubricants. The present study investigates MLFS for the precipitation-hardenable alloy AA2024-T3 using a process parameter that yields a high build rate relevant for industrial applications. The fatigue performance is shown and the microstructural and the mechanical anisotropy is examined. The fatigue properties in deposition direction show a high cycle fatigue limit of 170.5 MPa and a decrease in the maximum stress level compared to the base material due to precipitate overageing. The microstructure shows a Brass{011}⟨211⟩ texture at the bottom of the layers due to the application of high axial forces. In the center of the layer, no preferred texture was observed, while B{1¯12}⟨110⟩/B¯{11¯2¯}⟨1¯1¯0⟩ shear textures were observed at the top part of the deposited layers. An elongated grain morphology with aspect ratios above 2 is present over the entire layer height. These microstructural characteristics cause anisotropy in mechanical properties, with highest ultimate tensile strength and elongation in deposition direction, i.e., 408 ± 5 MPa and 18 ± 3 % respectively, and the lowest values along the build direction, i.e., 377 ± 21 MPa and 9 ± 3 % respectively. The observed behavior is of considerable importance for the industrial design and application of components manufactured with MLFS as they show that MLFS can also result in anisotropic material properties, depending on the chosen process parameters. It requires careful selection of the right combination of stud material and process parameters to achieve isotropic properties in the deposited structure.

KW - AA2024

KW - Anisotropy

KW - Fatigue

KW - Mechanical property

KW - Multi-layer friction surfacing

KW - Engineering

UR - http://www.scopus.com/inward/record.url?scp=85217192181&partnerID=8YFLogxK

U2 - 10.1007/s40964-025-00969-x

DO - 10.1007/s40964-025-00969-x

M3 - Journal articles

AN - SCOPUS:85217192181

VL - 10

SP - 6279

EP - 6293

JO - Progress in Additive Manufacturing

JF - Progress in Additive Manufacturing

SN - 2363-9512

IS - 9

M1 - 146582

ER -