TY - JOUR

T1 - Influence of laser shock peening on the residual stresses in additively manufactured 316L by Laser Powder Bed Fusion: A combined experimental-numerical study

AU - Sandmann, Paul

AU - Keller, Sören

AU - Kashaev, Nikolai

AU - Ghouse, Shaaz

AU - Hooper, Paul A.

AU - Klusemann, Benjamin

AU - Davies, Catrin M.

N1 - BK and NK acknowledge the funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - project number 459713992 . Publisher Copyright: © 2022 The Author(s)

PY - 2022/12/1

Y1 - 2022/12/1

N2 - Detrimental subsurface tensile residual stresses occur in laser powder bed fusion (LPBF) due to significant temperature gradients during the process. Besides heat treatments, laser shock peening (LSP) is a promising technology for tailoring residual stress profiles of additively manufactured components. A multi step process simulation is applied aiming at predicting the residual stress state after applying LSP to a cuboid shaped specimen manufactured by LPBF in two different building directions as well as comparing it with a post-build heat treatment. The validity of the numerical simulation is evaluated based on comparisons of residual stresses determined by incremental hole drilling technique within different stages of the multi step process: in the as-build condition, after subsequent heat treatment as well as after applying LSP to the as-build and heat treated specimens, showing overall a good experimental-numerical agreement throughout each of the process stages. Applying a heat treatment to the as-build LPBF sample at 700°C for 6h showed not to be effective in eliminating the surface tensile stress entirely, reducing the tensile residual stresses by 40%. However, the application of LSP on LPBF components showed promising results: LSP was able even to convert the detrimental near surface tensile residual stresses in the LPBF component into compressive residual stresses next to the surface, which is known to be beneficial for the fatigue performance.

AB - Detrimental subsurface tensile residual stresses occur in laser powder bed fusion (LPBF) due to significant temperature gradients during the process. Besides heat treatments, laser shock peening (LSP) is a promising technology for tailoring residual stress profiles of additively manufactured components. A multi step process simulation is applied aiming at predicting the residual stress state after applying LSP to a cuboid shaped specimen manufactured by LPBF in two different building directions as well as comparing it with a post-build heat treatment. The validity of the numerical simulation is evaluated based on comparisons of residual stresses determined by incremental hole drilling technique within different stages of the multi step process: in the as-build condition, after subsequent heat treatment as well as after applying LSP to the as-build and heat treated specimens, showing overall a good experimental-numerical agreement throughout each of the process stages. Applying a heat treatment to the as-build LPBF sample at 700°C for 6h showed not to be effective in eliminating the surface tensile stress entirely, reducing the tensile residual stresses by 40%. However, the application of LSP on LPBF components showed promising results: LSP was able even to convert the detrimental near surface tensile residual stresses in the LPBF component into compressive residual stresses next to the surface, which is known to be beneficial for the fatigue performance.

KW - Laser shock peening

KW - Laser powder bed fusion

KW - LPBF 316L stainless steel

KW - Residual stress

KW - Finite element analysis

KW - Additive manufacturing

KW - Engineering

UR - http://www.scopus.com/inward/record.url?scp=85140446345&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/d4ed82b5-9fa8-3569-8f0a-c6c89400f5e7/

U2 - 10.1016/j.addma.2022.103204

DO - 10.1016/j.addma.2022.103204

M3 - Journal articles

VL - 60

JO - Additive Manufacturing

JF - Additive Manufacturing

SN - 2214-8604

IS - Part A

M1 - 103204

ER -