Fatigue of cast aluminium alloys under constant and variable-amplitude loading

Dabayeh, A.; Xu, Rui; Du, Borui; Topper, T. H.

doi:10.1016/0142-1123(95)00073-9

Cited by 57 publications

(34 citation statements)

References 8 publications

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“…The values used for A356-T6 were Y = 2/π and ∆K th,eff = 1.5 MPa √ m. These were not experimentally determined, but were synthesized from a large compilation of published data [1,7,26,27,28,29]. While the LEFM approach requires an experimentally determined effective threshold stress intensity factor and a description of the defect shape to estimate the crack shape factor, this approach can be used to account for multiaxial complex loading and account for load ratio effects.…”

Section: Lefm Approachmentioning

confidence: 99%

Multiaxial Kitagawa analysis of A356-T6

Roy

Nadot

Nadot-Martin

et al. 2011

International Journal of Fatigue

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Experimental Kitagawa analysis has been performed on A356-T6 containing natural and artificial defects. Results are obtained with a load ratio of R = −1 for three different loadings: tension, torsion and combined tensiontorsion. The critical defect size determined is 400 ±100 µm in A356-T6 under multiaxial loading. Below this value, the microstructure governs the endurance limit mainly through Secondary Dendrite Arm Spacing (SDAS). . It is shown that the CDM and gradient methods are accurate; however fatigue data for three loading conditions is necessary to allow accurate identification of an endurance limit.

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Section: Lefm Approachmentioning

confidence: 99%

Multiaxial Kitagawa analysis of A356-T6

Roy

Nadot

Nadot-Martin

et al. 2011

International Journal of Fatigue

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“…It is the combination of pores and other metallurgical defects to cause the decrease in material properties observed among the three batches. This combination of casting defects might well be the reason for the observed large decrease in material characteristics as compared to literature sources [2][3][4][5]. In the authors' opinion, a change in the spruerunner design may be more representative of real work conditions, i.e.…”

Section: Resultsmentioning

confidence: 69%

“…However, one of the major drawbacks for conventional and even more advanced casting techniques is the formation of shrinkage and gas cavities, often coupled with other defects: cold fills, alumina skins, dross [1]. The literature on the influence of casting defects on the material properties of cast aluminium alloys is quite broad [2][3][4][5][6][7][8][9]. It is generally acknowledged that the static and fatigue strength of materials containing defects is lower than that of a defect free material.…”

Section: Introductionmentioning

confidence: 99%

Static and fatigue strength of a die-cast aluminium alloy under different feeding conditions

Avalle¹,

Belingardi²,

Cavatorta³

2002

Proceedings of the I MECH E Part L Journal of Materials:Design and Applications

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This paper reports investigations of the influence of porosity and casting defects on the static and constant-amplitude fatigue strength of a die-cast aluminium alloy. Three batches of specimens, differing in the sprue-runner design and consequently in content and types of defects, were tested in 'as-cast' conditions. Defects consisted of gas and shrinkage pores as well as cold fills, dross and alumina skins. Casting defects were observed to reduce significantly the static and fatigue properties of the material. Whereas for the static characteristics the decrease was progressive with the porosity range, for the fatigue strength the decrease was most significant from the lowest to the middle porosity range. The batches were classified with regard to the porosity level, as the metallurgical defects were not detectable through X-ray examination. The content and size of metallurgical defects were observed to increase together with the porosity level. Scanning electron microscopy (SEM) observation of the fracture surfaces demonstrated the important role played by dross, alumina skins and, above all, cold fills on the fatigue fracture

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“…The effect of solidi cation time and heat treatment on the tensile properties of aluminum alloys has been studied and documented. Several studies 1,9,10) in A319 aluminum alloys found that fatigue cracks initiated from casting pores that were almost always located either close to or at the specimen surface. However, the effect of solidi cation time on the high temperature fatigue properties of A319-type alloys is less well documented.…”

Section: Introductionmentioning

confidence: 99%

Effect of Microstructure on High Temperature Mechanical Properties of A319 Casting Alloy for Automotive Cylinder Heads

Kim

Jeong

2016

Mater. Trans.

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A quantitative study has been conducted to evaluate the relationship between microstructural features such as secondary DAS (dendrite arm spacing), eutectic structures and the mechanical behaviors of A319 casting alloys. Depending on the cooling rate affecting the primary and eutectic microstructure, the storage elastic modulus measured by DMA (dynamic mechanical analysis) increased with decreasing DAS, with a concomitant increase in the tensile strength and elongation at RT and also high tempertures. Contrarily, the thermal expansion coef cient increased with increasing temperature, but did not vary with microstructural changes. The hardness of the eutectic phase increased with increasing DAS due to the enlarged size of the eutectic particles, whereas the hardness of the primary phase was similar regardless of DAS, owing to the precipitates that formed during heat treatment. The increase of both of LCF (low cycle fatigue) and HCF (high cycle fatigue) lives with decreasing DAS was observed, mainly due to homogeneous deformation owing to the ne size of eutectic silicon and Fe intermetallic particles. The results of fractography observation showed that ner α-Al and eutectic phases were effective to the resistance of fatigue crack initiation and propagation due to the shorter crack path along the secondary particles. The LCF lives increased with increasing test temperature according to the Cof n-Manson relation due to the larger elongation. On the other hand, an analysis of the fatigue lives with the hysteresis loop energy, which consists of both strength and elongation, showed that the fatigue lives were normalized with an alloy of the same strengthening mechanisms regardless of the test temperature. DMA analysis demonstrated that the mechanical properties of the Al 2 Cu precipitate hardened alloy were maintained at temperatures greater than 250 C, whereas degradation in the mechanical properties of the Mg-containing alloy occurred at 170 C due to coarsening in the precipitation phase of Mg 2 Si.

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Fatigue of cast aluminium alloys under constant and variable-amplitude loading

Cited by 57 publications

References 8 publications

Multiaxial Kitagawa analysis of A356-T6

Multiaxial Kitagawa analysis of A356-T6

Static and fatigue strength of a die-cast aluminium alloy under different feeding conditions

Effect of Microstructure on High Temperature Mechanical Properties of A319 Casting Alloy for Automotive Cylinder Heads

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