On the distributions of fatigue lives and defect-sizes in the die-cast magnesium alloy AZ91

Ishihara, Sotomi; Yoshifuji, S.; Namito, Tomonori; Goshima, Takahito

doi:10.1016/j.proeng.2010.03.136

Cited by 10 publications

(4 citation statements)

References 5 publications

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“…There are also studies focused on the low cycle fatigue (LCF) and high cycle fatigue (HCF) behavior of magnesium alloys, especially at room temperature (RT) [24][25][26][27] .Very few studies in the literature use various thin film coating techniques to improve the mechanical (tensile) and fatigue properties of AZ Mg alloys.…”

Section: Introductionmentioning

confidence: 99%

Fatigue and tensile behaviour of Ti+TiN+Ti+TiVN multilayer nitride films coated on AZ91 magnesium alloy by closed field unbalanced magnetron sputtering

Alibeyoğlu,

Karabudak,

Yeşildal

et al. 2024

Mater. Res. Express

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Despite their extensive use in the automotive and aerospace industries, Mg and Mg alloys, which are light metals, exhibit low fatigue and tensile strength. In this study, transition metal-nitride (TMN) multilayer coatings (Ti+TiN+Ti+TiVN) were coated twice on AZ91 Mg alloy using a Confined Field Unbalanced Magnetron Sputtering (CFUBMS) system to increase fatigue and tensile strength. The structural properties of the films were analyzed by using X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive spectrometry (EDS) methods, and the mechanical properties were analyzed by rotating bending fatigue and tensile testing machines. Ti+TiN+Ti+TiVN multilayer nitride surface coatings on AZ91 Mg alloys showed a dense and columnar microstructure and according to XRD results (111) was the preferred orientation with the dominant peak. The fatigue limit value of the AZ91 base material was fixed at 60.46 MPa, while it increased to 68.48 MPa after being coated with multilayer nitride. Along with the multilayer nitride coating, the tensile strength increased from 169.98 MPa to 175.43 MPa. As a result, the multilayer hard nitride coating with low surface roughness, which fills the defects, notches, and voids on the surface of the AZ91 base material, increased the fatigue and tensile strength in parallel. Based on the outcomes of the research, the literature has been enriched with an innovative approach through the enhancement of fatigue and tensile strengths by applying a CFUBMS coating to lightweight metals and alloys, such as AZ91, especially in the transportation industry where lightness and dynamic load resistance are essential.

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Section: Introductionmentioning

confidence: 99%

Fatigue and tensile behaviour of Ti+TiN+Ti+TiVN multilayer nitride films coated on AZ91 magnesium alloy by closed field unbalanced magnetron sputtering

Alibeyoğlu,

Karabudak,

Yeşildal

et al. 2024

Mater. Res. Express

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“…Weld defects played as crack initiation points in TIG weld joints [14]. Additionally, despite not being focused on non-combustible magnesium alloys, numerous studies have demonstrated the relationship between microstructure and fatigue strength properties of magnesium alloys [20][21][22][23][24][25][26][27][28][29][30][31]. Li ZM et al reported that in absence of casting flaws, the high cycle fatigue properties of a cast NZ30K(Mg-3%Nd-0.2%Zn-0.45%Zr) alloy strongly depend on its grain size [21].…”

Section: Introductionmentioning

confidence: 99%

Fatigue strength and fatigue crack initiation mechanism in non-combustible Mg-4%Al-1%Ca-0.2%Mn alloys and its TIG and MIG weld joints

SHAO,

THAO,

NAKATA

et al. 2023

Preprint

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Fatigue mechanism of a Mg-4%Al-1%Ca (hereinafter referred to as AX41) non-combustible magnesium alloy and its TIG(Tungsten Inert Gas) and MIG(Metal Inert Gas) weld joint was investigated through the plane bending fatigue and crack propagation tests. Results of plane bending fatigue tests showed that fatigue strengths of TIG and MIG weld joints were lower than that of the base metal (BM), while a similar fatigue strength at 107 cycles was found in both TIG and MIG weld joints. However, a TIG weld joint showed the highest crack propagation resistance among tested samples in crack propagation tests. Scanning electron microscopy and electron backscatter diffraction (EBSD) analysis were used to investigate the relationship between microstructural factors and crack initiation mechanism of AX41 alloy and its weld joint. Cracks were found to initiate from grains in BM, while weld defects became a crack initiation site in a MIG weld joint. However, both grains and weld defects were observed as a crack initiation site in a TIG weld joint. Results of EBSD analysis indicated that fatigue crack initiation in TIG weld joint was favored in large grains with high Schmid factors. The critical value of initial crack length was discussed in correlation between the maximum grain size and the maximum weld defects/inclusions size on the fatigue crack initiation mechanisms. As a result, prediction method of the fatigue strength at 107 cycles was proposed based on the hardness and weld defects/inclusions size.

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“…In past works, the microstructure‐affected micromechanisms of fatigue crack growth in Mg high‐pressure die‐casting alloys manifested by the effects of dendrite cell size, interdendritic Al‐rich solid solution layer and surface segregation phenomena have been studied . Recently, the fatigue behaviour of AZ91 magnesium alloy has been studied, focusing on different types of processes and heat treatments …”

Section: Introductionmentioning

confidence: 99%

“…13 Recently, the fatigue behaviour of AZ91 magnesium alloy has been studied, focusing on different types of processes and heat treatments. [14][15][16][17][18] The aim of the present study is to identify casting defects present in this AZ91D high-pressure die-casting alloy and to analyse and evaluate the influence of and correlation between each casting defect type and the fatigue behaviour to obtain adequate properties of the material that will be used. This paper has been carried out by conducting a series of fatigue tests using AZ91D samples that were manufactured using the same casting technique as inservice components to reproduce the same surface conditions for the specimens as for the in-service components.…”

Section: Introductionmentioning

confidence: 99%

Magnesium alloy defectology AZ91D high‐pressure die cast and influence on the fatigue behaviour

Lorenzo

Alegre

Cuesta

2013

Fatigue Fract Eng Mat Struct

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The fatigue results of a high‐pressure die cast of AZ91D magnesium alloy revealed the presence of different types of casting defects, which account for the large scattering in the number of cycles until failure. In this paper, this magnesium alloy has been analysed, and in an effort to reproduce the same surface and material conditions exhibited in automotive service components, the fatigue test samples were manufactured using a die that employs the same casting process and equipment. To examine the fracture surface of all the fatigue tests, a scanning electron microscope was used, and the source of the failure, so as to relate fatigue life with casting defect type, was identified. Five casting defect types that influence the fatigue behaviour were observed and classified: (a) isolated pores (blowholes), (b) micro‐porosity areas, (c) circular shrinkage cavities associated with the contraction and geometry of the casted specimen, (d) surface burrs associated with the die‐casting mould and (e) the presence of oxides or inclusions.

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On the distributions of fatigue lives and defect-sizes in the die-cast magnesium alloy AZ91

Cited by 10 publications

References 5 publications

Fatigue and tensile behaviour of Ti+TiN+Ti+TiVN multilayer nitride films coated on AZ91 magnesium alloy by closed field unbalanced magnetron sputtering

Fatigue and tensile behaviour of Ti+TiN+Ti+TiVN multilayer nitride films coated on AZ91 magnesium alloy by closed field unbalanced magnetron sputtering

Fatigue strength and fatigue crack initiation mechanism in non-combustible Mg-4%Al-1%Ca-0.2%Mn alloys and its TIG and MIG weld joints

Magnesium alloy defectology AZ91D high‐pressure die cast and influence on the fatigue behaviour

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