Effects of particulate volume fraction on cyclic stress response and fatigue life of AZ91D magnesium alloy metal matrix composites

Hassan, Hala A.; Lewandowski, John J.

doi:10.1016/j.msea.2014.02.021

Cited by 32 publications

(18 citation statements)

References 30 publications

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“…Wrought Mg alloys with a hexagonal close-packed (HCP) crystal structure have strong basal textures formed by rolling and extrusion, i.e., the c-axes of most grains are perpendicular to the extrusion or rolling direction. There have been a number of studies on low-cycle fatigue (LCF) behavior of extruded Mg alloys, such as AZ31/AZ31B , AZ61/AZ61A [27][28][29][30][31][32][33][34], AM30 [35][36][37][38], AM50 [39], ZK60 [40][41][42][43][44][45][46], and AZ91D [47]. These extruded Mg alloys exhibit common characteristics of cyclic deformation.…”

Section: Introductionmentioning

confidence: 99%

Cyclic deformation and fatigue of extruded AZ31B magnesium alloy under different strain ratios

Xiong

Jiang

2016

Materials Science and Engineering: A

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Cyclic deformation and fatigue behavior of extruded AZ31B magnesium (Mg) alloy were investigated under strain-controlled loading along the extrusion direction at different strain amplitudes with three strain ratios (ε = 1,). With a strain ratio of ε = , partial twinning-partial detwinning occurs at all strain amplitudes, leading to accumulation of deformation twins as the loading cycle is increased. With strain ratios being ε = and 1, partial twinning-complete detwinning is the cyclic deformation mechanism when the strain amplitude is higher than 0.35%. At a strain amplitude lower than 0.35%, dominant cyclic deformation mechanism is dislocation slips irrespective of the strain ratio. Compared with the cases of ε = and ε = , stronger cyclic hardening is exhibited at all the investigated strain amplitudes for ε =. Fatigue fracture surfaces show regions with lamellar-like and dimplelike features. Lamellar-like feature existing in the crack initiation and stable propagation region are mainly due to twinning-detwinning during cyclic deformation. The dimple-like feature formed in the unstable crack propagation and final rupture region mainly arises from severe intragranular plastic deformation by dislocation slips. At the same strain amplitude, the lamellar-like traces become more aggravated with a lower stain ratio. The strain-fatigue life curves exhibit a distinguishable kink at strain ratios ε = 1 and. The fatigue life with ε = shows the highest and that with is the lowest at the same strain amplitude. The Smith-Watson-Topper (SWT) fatigue criteria can correlate well the fatigue experiments of AZ31B Mg alloy under different strain ratios.

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Section: Introductionmentioning

confidence: 99%

Cyclic deformation and fatigue of extruded AZ31B magnesium alloy under different strain ratios

Xiong

Jiang

2016

Materials Science and Engineering: A

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“…% of CNTs. The increase of the microhardness can be attributed to: (i) grain refinement [ 39 ]; (ii) the high hardness and toughness of CNTs [ 36 ]; (iii) the higher constraint to localized matrix deformation during indentation, because of the presence of homogeneously dispersed nanoparticles in the matrix [ 32 ]. However, the decrease in microhardness can be explained by two reasons: the first is the presence of an agglomeration of CNTs in the composites, which can be observed in Figure 3 d,e; the other is the lower densification (greater amount of micropores) of the composites, which leads to a deterioration of the microhardness to some degree.…”

Section: Resultsmentioning

confidence: 99%

The Effects of Carbon Nanotubes on the Mechanical and Wear Properties of AZ31 Alloy

Zhou

Ren

et al. 2017

Materials

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Carbon nanotube (CNT)-reinforced AZ31 matrix nanocomposites were successfully fabricated using a powder metallurgy method followed by hot extrusion. The influence of CNTs on microstructures, mechanical properties, and wear properties were systematically investigated by optical microscope (OM), scanning electron microscope (SEM), X-ray diffraction (XRD), hardness test, tensile test, and wear test. The results revealed that the nanocomposites showed a slightly smaller grain size compared with the matrix and uniform distribution that CNTs could achieve at proper content. As a result, the addition of CNTs could weaken basal plane texture. However, the yield strength and ultimate tensile strength of the composites were enhanced as the amount of CNTs increased up to 2.0 wt. %, reaching maximum values of 241 MPa (+28.2%) and 297 MPa (+6.1%), respectively. The load transfer mechanism, Orowan mechanism, and thermal mismatch mechanism played important roles in the enhancement of the yield strength, and several classical models were employed to predict the theoretical values. The effect of CNT content on the friction coefficient and weight loss of the nanocomposites was also studied. The relationships between the amount of CNTs, the friction coefficient, and weight loss could be described by the exponential decay model and the Boltzmann model, respectively.

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“…This asymmetrical behavior is mainly caused by the directional activation of

({}, 10 \overset{1}{true} 2)

tension twinning . It is, therefore, expected that the fatigue behavior of wrought Mg alloys would be influenced by

({}, 10 \overset{1}{true} 2)

tension twinning which can be resulted by preloading and material processes …”

Section: Introductionmentioning

confidence: 99%

“…[13][14][15][16] It is, therefore, expected that the fatigue behavior of wrought Mg alloys would be influenced by 1012 È É tension twinning which can be resulted by preloading and material processes. [17][18][19][20] Loading magnitude plays an important role in the deformation mechanisms of Mg alloys under cyclic loading. Earlier studies [21][22][23][24][25][26][27][28][29][30][31][32] reveal that in the strain life fatigue Nomenclature: ED, extrusion direction; TD, transverse direction; ED −9.4% , precompressed to 9.4% along the ED; XRD, X ray diffraction; SEM, scanning electron microscope; R ε , strain ratio; λ, twin fraction parameter; λ Norm , normalized λ value curves of pure Mg and Mg alloys (AZ31B, AZ61, and ZK60), there exist a kink point that demarcates the dominant deformation mechanisms.…”

Section: Introductionmentioning

confidence: 99%

Effect of initial texture on fatigue properties of extruded ZK60 magnesium alloy

Xiong

Gong

Jiang

2018

Fatigue Fract Eng Mat Struct

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The effect of initial texture on cyclic deformation behavior of extruded ZK60 magnesium (Mg) alloy was experimentally investigated under strain‐controlled loading with the strain amplitudes at 4%, 1%, and 0.35%. The testing specimens were taken from extrusion direction (ED), transverse direction (TD), and a material precompressed to 9.4% along the ED (ED−9.4%). At a high strain amplitude of 4%, the cyclic deformation modes of ED and ED−9.4% specimens are similar, and they experience twinning exhaustion → slip and detwinning exhaustion → slip during each loading cycle. At a medium strain amplitude of 1%, twinning‐detwinning is involved in the cyclic deformation, but different deformation mechanisms were observed in the 3 different specimens. Partial twinning‐complete detwinning mode dominates the cyclic deformation in the ED specimen, while partial detwinning‐retwinning mode occurs in the ED−9.4% specimen. For the TD specimen, both basal slip and {}10true1¯20.25emtension twinning occur during cyclic deformation. At a low strain amplitude of 0.35%, dislocation slips dominate the deformation for the ED specimen with a few observable tension twins. For the ED−9.4% specimen, initially twined texture increases the ductility of the material and enhances fatigue life as compared with the other 2 specimens.

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Effects of particulate volume fraction on cyclic stress response and fatigue life of AZ91D magnesium alloy metal matrix composites

Cited by 32 publications

References 30 publications

Cyclic deformation and fatigue of extruded AZ31B magnesium alloy under different strain ratios

Cyclic deformation and fatigue of extruded AZ31B magnesium alloy under different strain ratios

The Effects of Carbon Nanotubes on the Mechanical and Wear Properties of AZ31 Alloy

Effect of initial texture on fatigue properties of extruded ZK60 magnesium alloy

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