Showing papers on "Strain hardening exponent published in 2017"
TL;DR: The tensile properties of CrCoNi have been shown to be significantly better than those of CrMnFeCoNi, a high-entropy alloy as discussed by the authors, and the deformation mechanism responsible for its superiority has been investigated.
720 citations
TL;DR: In this paper, a new cementitious material, ultra-high ductile cementitious composites (UHDCCs), is developed with the specially selected polyethylene (PE) fibers.
298 citations
TL;DR: In this paper, a selective laser melted (SLM) AlSi10Mg alloy has unique hierarchical microstructures, including micro-sized Al grains and transgranular ultrafine cellular structures around primary Al.
284 citations
TL;DR: In this article, the authors developed constitutive equations for the full engineering stress-strain response of hot-rolled carbon steels, which offer different options for the representation of the strain hardening region and feature an elastic response up to the yield point.
269 citations
TL;DR: In this article, a dislocation density-based continuum plasticity model was proposed to investigate the strain hardening of a gradient interstitial-free steel by developing a dislocated density-and back stress model, in which the interaction of the component layers in the gradient structure was represented by incorporating geometrically necessary dislocations and back stress.
188 citations
TL;DR: In this paper, the effects of cold rolling followed by annealing on the mechanical properties and dislocation substructure evolution of undoped and 1.5Cr6 high entropy alloys (HEAs) have been investigated.
171 citations
TL;DR: In this article, the strengthening and strain hardening mechanisms in an aged high-Mn lightweight steel (Fe-30.4Mn-8Al-1.2C, wt.%) were studied by electron channeling contrast imaging (ECCI), transmission electron microscopy (TEM), atom probe tomography (APT) and correlative TEM/APT.
168 citations
TL;DR: In this paper, a ductile fracture model is proposed to describe shear fracture of sheet metals from shear to balanced biaxial tension via uniaaxial and plane strain tension.
161 citations
13 Jan 2017-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, the properties of AM-Selective Laser Melting (SLM) AlSi10Mg parts under a static regime have been investigated, while the strain rate sensitivity of these materials, to the best of our knowledge, has not been discussed in the literature.
Abstract: Implementation of Additive Manufacturing (AM) parts in the growing applications within the automotive and aerospace industries encourages further investigations of the material behavior under various strain rates, spanning from quasi-static to the high strain rate regimes. Although mechanical properties of AM-Selective Laser Melting (SLM) AlSi10Mg parts under a static regime have been investigated, the strain rate sensitivity of these materials, to the best of our knowledge, has not been discussed in the literature. In this work, the properties of AM-SLM AlSi10Mg material were systematically investigated under a wide range of strain rates, spanning from 2.77×10−6 to 2.77×10−1 S−1. The AM-SLM AlSi10Mg alloy, as opposed to Al alloys fabricated by conventional methods, was found to be strain rate sensitive with significant changes to the flow stress and strain hardening exponents with an increase in strain rate. The fracture mechanisms of these specimens, built in different orientations, are discussed.
156 citations
24 Mar 2017-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: The tensile deformation and strain hardening behaviors of an equimolar CoCrFeMnNi high-entropy alloy (HEA) were investigated and compared with low and medium entropy equiatomic alloys (LEA and MEA) as mentioned in this paper.
Abstract: The tensile deformation and strain hardening behaviors of an equimolar CoCrFeMnNi high-entropy alloy (HEA) were investigated and compared with low and medium entropy equiatomic alloys (LEA and MEA). The HEA had a lower yield strength than the MEA because the addition of Mn weakens solid solution hardening in the HEA. However, deformation twinning induced the multiple stage strain hardening behavior of the HEA and enhanced strength and elongation. Using tensile-interrupted electron backscatter diffraction analysis, geometrically necessary dislocations were observed as plume-shaped features in grain interior, and a considerable texture was characterized, which is typical of face centered cubic metals. Moreover, the relationship between favorably oriented grains and twinning in the HEA bore a clear resemblance to the same tendency in TWIP steels. The thickness of the twin bundles was less than 100 nm. A high density of stacking defects was found in the nanotwins. Nano twinning and stacking faults were found to contribute to the remarkable mechanical properties. Deformation induced twinning not only demonstrated the dynamic Hall-Petch effect but also changed dislocation cell substructures into microband structures.
155 citations
TL;DR: It is proposed that the excellent strain hardening ability gives rise to remarkable resistance to shear localization, which makes this material an excellent candidate for penetration protection applications such as armors.
Abstract: The mechanical behavior of a single phase (fcc) Al0.3CoCrFeNi high-entropy alloy (HEA) was studied in the low and high strain-rate regimes. The combination of multiple strengthening mechanisms such as solid solution hardening, forest dislocation hardening, as well as mechanical twinning leads to a high work hardening rate, which is significantly larger than that for Al and is retained in the dynamic regime. The resistance to shear localization was studied by dynamically-loading hat-shaped specimens to induce forced shear localization. However, no adiabatic shear band could be observed. It is therefore proposed that the excellent strain hardening ability gives rise to remarkable resistance to shear localization, which makes this material an excellent candidate for penetration protection applications such as armors.
TL;DR: In this article, a combination of solid solution hardening, nanotwinning and precipitation hardening mechanisms is proposed for single-phase Mo 10 HEAs with face centered cubic (FCC) structure.
TL;DR: In this paper, a novel idea of using carbon nanofibers (CNFs) to strengthen the interface transition zone (ITZ) and to enhance the interface frictional bond strength between polyethylene (PE) fibers and cement-based matrix was proposed and realized by coating CNFs on surface of PE fibers through hydrophobic interactions.
TL;DR: In this paper, a detailed investigation into the anisotropic strain hardening, tension/compression yield asymmetry, and evolution of crystallographic texture of rolled WE43 rare earth magnesium alloy during quasi-static tension and compression at room temperature is presented.
TL;DR: In this article, a deformation-based design approach called the continuous strength method (CSM) has been proposed for the design of stocky cross-sections, which relates the strength of a cross-section to its deformation capacity and employs a bi-linear (elastic, linear hardening) material model to account for strain hardening.
TL;DR: In this paper, an ambient temperature cured "one-part" strain hardening geopolymer composite (SHGC) was developed as a "dry mix" using a small amount of solid activator and eliminating the necessity for heat curing.
TL;DR: In this paper, a temperature-dependent micromechanical behavior of medium-Mn transformation-inducedplasticity (TRIP) steel with a nominal chemical composition of Fe-0.1C-10Mn-2Al (mass%) fabricated by intercritical annealing 650°C for 1 1/h after cold-rolling was investigated using in situ high-energy X-ray diffraction (HE-XRD) with uniaxial tensile tests at temperatures of 100, 25 and 50°C.
TL;DR: In this paper, the mechanical response and texture evolution of rare-earth-containing magnesium alloy sheet, ZEK100, are measured under uniaxial (tension and compression) loading along the rolling direction (RD), 45° to rolling direction(DD), transverse direction (TD) and normal direction (ND), at the strain rate of 10 −4 to 3 ǫ 10 3 s −1, and temperatures of 22 Â c and 150 Â C.
TL;DR: Strain-hardening cementitious composites (SHCCs) exhibiting tensile strainhardening and multiple cracking are attractive for many structural applications However, the high cement content makes them difficult to construct.
Abstract: Strain-hardening cementitious composites (SHCCs) exhibiting tensile strain-hardening and multiple cracking are attractive for many structural applications However, the high cement content
TL;DR: In this paper, three different types of strainhardening, cement-based composites (SHCC) as well as their constitutive cementitious matrices were investigated under uniaxial quasi-static and impact tensile loading.
TL;DR: In this article, a new ultra-high-strength duplex lightweight Fe-0.5C-12Mn-7Al-(0,3)Cu (wt%) steels have been developed by varying annealing temperature.
TL;DR: In this paper, a theoretical model is proposed to describe the structure-property relation of gradient-nanostructured stainless steels with nanotwin-nanograin composite structure, and the evolution and influence of the nano/micro cracks/voids are considered for predicting failure strain.
TL;DR: In this article, the deformation microstructures and their effect on the yield strength of austenitic stainless steels processed by large strain warm rolling were studied, and a power-law function was obtained between deformation grain sizes with a grain size exponent of 0.3.
TL;DR: In this article, a review of the Austenite-reverted-transformation annealing treatment routine, mechanical properties and deformation mechanisms and effect of heat treatment on microstructure and mechanical properties of medium-Mn steels are summarised.
Abstract: In the automotive industry, the current development trend of lightweight and low-emission vehicles requests for high-performance materials. Benefiting from an excellent balance of mechanical properties and production cost, medium-Mn steels have attracted extensive interest by materials scientists. Austenite-reverted-transformation annealing plays a vital role in stabilisation of retained austenite and grain refinement, resulting in a considerable amount of retained austenite. Localised deformation phenomenon is usually observed in the ultrafine-grained medium-Mn steels owing to the absence of strain hardening. The occurrence of transformation-induced-plasticity and/or twinning-induced-plasticity effect in austenite improves strain hardening effectively. In the current review, austenite-reverted-transformation annealing treatment routine, mechanical properties and deformation mechanisms and effect of heat treatment on microstructure and mechanical properties of medium-Mn steels are summarised.This ...
TL;DR: In this article, the effect of discontinuous fibres on the mechanical performance and on the microstructure of composite geopolymer materials has been evaluated, and the results indicate that room temperature cured, cement-free, strain hardening fiber-reinforced concrete with superior deflection capacity can be produced using a ternary binder mix reinforced by 2% PVA fibre or with 2% and 3% of 13mm length steel fibre.
TL;DR: In this paper, the Zener-Hollomon equation is modified to describe the mechanical response of the ultrafine-grained titanium over the strain rate range 10−5 to 103 s−1.
TL;DR: A fully recrystallized ultrafine-grained (UFG) Fe 22.6wt.%C twinning-induced plasticity (TWIP) steel with mean grain size of 576nm was fabricated by cold rolling and annealing process as mentioned in this paper.
TL;DR: In this paper, deformation-induced β to α″ phase transformation dominates the early stage deformation and deformation twinning is activated and becomes the dominating deformation mechanism afterward, after the deformation over the ultimate tensile strength.
TL;DR: In this article, the authors numerically studied the role of exhaustion of twinning in magnesium alloys under twinning dominated conditions, based on the large strain elastic visco-plastic self-consistent model.
TL;DR: In this paper, the deformation evolution across several crystal orientations for the equiatomic FeNiCoCrMn high entropy alloy at room temperature (RT) and 77 K was explored.