Investigation of Portevin–Le Chatelier Band Strain and Elastic Shrinkage in Al-Based Alloys Associated with Mg Contents

Cai, Yong; Yang, Sen; Fu, Shaojing; Zhang, Di; Zhang, Qingchuan

doi:10.1016/j.jmst.2016.05.012

Cited by 56 publications

(17 citation statements)

References 44 publications

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“…Aluminum alloys often exhibit serrated flow after a critical strain during plastic deformation in the range of −50 • C to 100 • C. Zn and Mg atoms are the main factor causing serrated yield [10,32,33]. For the 440-W specimen, serrated flow occurred predominantly in association with higher Zn and Mg concentrations.…”

Section: High Improvement Of Tensile Ductility In the Fsped Sample VImentioning

confidence: 99%

Examination of the High Tensile Ductility Improvement in an As-Solutionized AA7075 Alloy with the Aid of a Friction Stir Process

Hung

Lui

2019

Metals

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The ductility enhancement of an AA7075 aluminum alloy aided by a friction stir process (FSP) and various heat treatments was investigated and compared in terms of outcome with full annealing (O). The results indicate that a big improvement in the tensile ductility was achieved by freezing the sample at temperatures below 0 °C after the solution treatment and water quenching (W treatment), and further improvement could be acquired via a friction stir process due to grain refinement (<6 μm). Thus, the observed improvement in tensile ductility can be explained by the fact that the W treatment and friction stir processing scheme had an increased strain-hardening effect and decreased the presence of intermetallic particles that are harmful to uniform tensile deformation, consequently causing strain localization in the early stage of tensile deformation, which suggests that these treatment are a potential solution for insufficient formability. In general, the elongation to failure values for the W and FSP-treated specimens (>40%) were at least 1.5-fold greater than that of the annealed alloy. In addition, serrated flow could be observed in the tensile flow curves, and both the Piobert–Lüders effect and the Portevin–LeChatelier (PL) effect could be observed. The enhancement in the tensile ductility was examined in terms of the existence of intermetallic particles and the supersaturated concentration of the solid solution.

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Section: High Improvement Of Tensile Ductility In the Fsped Sample VImentioning

confidence: 99%

Examination of the High Tensile Ductility Improvement in an As-Solutionized AA7075 Alloy with the Aid of a Friction Stir Process

Hung

Lui

2019

Metals

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“…Therefore, it will provide more time for the plastic relaxation of the internal stress, thereby resulting in a smaller spatial coupling force, that comes from elastic stresses related to local plastic incompatibilities and controls the band propagation [54], further causing the switch from type A to type (A+B). This view is supported by Cai et al [13], who reported that the variation of spatial coupling strength is responsible for the change of band propagation types. Furthermore, Fig.…”

Section: Stress Drop Magnitude and The Number Of Stress Drops Per Unimentioning

confidence: 59%

“…The PLC effect typically manifests itself as serrated or jerky flow in stress-strain curves and localized deformation bands in specimens of metallic alloys [13]. Up to now, there is no unique mechanism for the PLC effect in different systems, though the repetitive releasing and arresting of mobile dislocations are considered as the common factor to be responsible for its occurrence [14].…”

Section: Introductionmentioning

confidence: 99%

Spatiotemporal characteristics of Portevin-Le Chatelier effect in Ti-Mo alloys under thermo-mechanical loading

Luo

Castany

Thuillier

et al. 2018

Materials Science and Engineering: A

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The Portevin-Le Chaterlier (PLC) effect in Ti-12Mo and Ti-15Mo alloys has been investigated by using uniaxial tensile tests in a temperature range of 25-350 ℃ with an applied strain rate of the order of 10 -3 s -1 , coupled with a digital image correlation (DIC) method. The experimental results show an increase of the yield stress from 25°C to 250°C followed by a decrease. Moreover, PLC effect occurs above 250°C and stress drop magnitude increases while the number of stress drops per unit time decreases with increasing the strain and temperature as well as decreasing Mo contents. These macroscopic features are related to the reduced intensity of interactions between ω phase particles and mobile dislocations as decreasing temperature and increasing Mo contents. Furthermore, a relatively higher temperature and lower Mo content tend to weaken the spatial cohesion of propagation bands and strengthen strain localization, leading to a change of PLC bands from type A to type B and the increase of strain rate within the PLC bands, which are related to the increased precipitation of ω phases.Additionally, the elongation at fracture is significantly influenced by PLC effect in Ti-Mo alloys.

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“…The Mg content can also affect the amplitude of the stress serration in the PLC phenomenon. Additionally, the critical strain rate varies with the Mg content because higher Mg levels lead to higher critical strain rates; however, this does not have any apparent effect on the width of the PLC bands [15]. The strain rate changes the serrations types [4,15].…”

Section: Introductionmentioning

confidence: 99%

“…Additionally, the critical strain rate varies with the Mg content because higher Mg levels lead to higher critical strain rates; however, this does not have any apparent effect on the width of the PLC bands [15]. The strain rate changes the serrations types [4,15]. For instance, in an Al-3 Mg wt % alloy, type A, B, and C oscillations occur when the strain rates are 10 −3 /s, 10 −4 /s, and 10 −5 /s, respectively [4].…”

Section: Introductionmentioning

confidence: 99%

Al/Niobium Diboride Nanocomposite’s Effect on the Portevin-Le Chatelier Phenomenon in Al-Mg Alloys

et al. 2019

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In Al-Mg alloys, the Portevin-Le Chatelier phenomenon, or dynamic strain aging, reveals itself as serrations upon plastic tensile deformation. This research evaluates this phenomenon when Al/NbB2 nanocomposite pellets are added to a magnesium-supersaturated Al matrix. A ball-milled 90 wt % Al and 10 wt % NbB2 nanocomposite helped inoculate an Al-Mg melt to incorporate the nanoparticles effectively. The melt was cast into rods that were cold-rolled into 1 mm diameter wires. Two sets were prepared: The first group was an as-cast set of samples, for comparison purposes, whereas the second was a solution-treated set. The solution treatment consisted of annealing followed by ice-water quenching. The results corroborating that the phenomenon was observable only in the specimens bearing the solution treatment, were used as the research baseline. Said treated alloy was compared to one containing the nanoparticles, which proved that the NbB2 particles caused a reduction of the serrated signal amplitude.

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Investigation of Portevin–Le Chatelier Band Strain and Elastic Shrinkage in Al-Based Alloys Associated with Mg Contents

Cited by 56 publications

References 44 publications

Examination of the High Tensile Ductility Improvement in an As-Solutionized AA7075 Alloy with the Aid of a Friction Stir Process

Examination of the High Tensile Ductility Improvement in an As-Solutionized AA7075 Alloy with the Aid of a Friction Stir Process

Spatiotemporal characteristics of Portevin-Le Chatelier effect in Ti-Mo alloys under thermo-mechanical loading

Al/Niobium Diboride Nanocomposite’s Effect on the Portevin-Le Chatelier Phenomenon in Al-Mg Alloys

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