TY - JOUR

T1 - Fatigue Life Assessment of Corroded AlSi10MgMn Specimens

AU - Schönowitz, Markus

AU - Fladischer, Stefan

AU - Oberreiter, Peter

AU - Maier, Bernd

AU - Grün, Florian

AU - Bauer-Troßmann, Kathrin

PY - 2024/10/5

Y1 - 2024/10/5

N2 - This study investigates the influence of pre-corrosion damage on the fatigue behaviorof AlSi10MgMn high-pressure die-cast specimens, using the statistical distribution of corrosiondepths. The analysis is conducted on two different surface conditions: an unmachined roughsurface (Ra = 5.05 μm) and a machined, polished surface (Ra = 0.25 μm). For the unmachinedspecimens, the corrosive damage manifests as homogeneously spread localized corrosion, whereasthe polished specimens exhibit less uniform but deeper corrosion. The average corrosion depth of thepolished specimens is found to be slightly higher (313 μm compared to 267 μm) with a broader depthdistribution. Specimens are tested under a constant bending load amplitude in laboratory conditionsat a stress ratio of R = 0 until fracture. A fracture mechanics-based methodology is developedto assess the remaining fatigue life of corroded specimens, utilizing short and long crack fracturemechanical parameters derived from SENB specimens. This model incorporates a thickness reductionof the critical specimen cross-section based on the corrosion depth distribution and combines it witha small initial crack of the intrinsic defect size (ae f f = 14 μm). Regardless of the surface condition,using the most frequent corrosion depth for thickness reduction provides a good estimate of thelong-life fatigue strength, while using the 90th percentile depth allows for a conservative assessment.

AB - This study investigates the influence of pre-corrosion damage on the fatigue behaviorof AlSi10MgMn high-pressure die-cast specimens, using the statistical distribution of corrosiondepths. The analysis is conducted on two different surface conditions: an unmachined roughsurface (Ra = 5.05 μm) and a machined, polished surface (Ra = 0.25 μm). For the unmachinedspecimens, the corrosive damage manifests as homogeneously spread localized corrosion, whereasthe polished specimens exhibit less uniform but deeper corrosion. The average corrosion depth of thepolished specimens is found to be slightly higher (313 μm compared to 267 μm) with a broader depthdistribution. Specimens are tested under a constant bending load amplitude in laboratory conditionsat a stress ratio of R = 0 until fracture. A fracture mechanics-based methodology is developedto assess the remaining fatigue life of corroded specimens, utilizing short and long crack fracturemechanical parameters derived from SENB specimens. This model incorporates a thickness reductionof the critical specimen cross-section based on the corrosion depth distribution and combines it witha small initial crack of the intrinsic defect size (ae f f = 14 μm). Regardless of the surface condition,using the most frequent corrosion depth for thickness reduction provides a good estimate of thelong-life fatigue strength, while using the 90th percentile depth allows for a conservative assessment.

U2 - 10.3390/met14101135

DO - 10.3390/met14101135

M3 - Article

VL - 14.2024

JO - Metals : open access journal

JF - Metals : open access journal

SN - 2075-4701

IS - 10

M1 - 1135

ER -