Anisotropic Deformation Behavior Research Articles

Anisotropic compressive deformation behavior of hot-rolled Mg-3Al-0.5Ce alloy

This work investigates the anisotropic compressive deformation of hot-rolled Mg-3Al-0.5Ce alloy and correlates it with microstructure and texture. Hot-rolled alloy had elongated and equiaxed grains with long-aligned Al11Ce3 precipitates within the grain boundaries along rolling direction (RD) and basal texture along normal direction (ND). Analytical and crystal plasticity-based viscoplastic self-consistent predominant twin reorientation (VPSC-PTR) approaches were employed to simulate the flow curve and texture evolution for deeper insight into the deformation behavior. For compression direction (CD)∥to RD and transverse direction (TD), the basal texture was ∼⊥ to CD, which favored {101¯2}〈101¯1〉 extension twins (ET). The ETs nucleate, broaden and engulf the parent matrices with strain, rotating the lattice by ∼86.4∘ about 〈21¯1¯0〉 axes to a geometrically hard orientation with c-axis ∼∥toCD, leading to sigmoidal flow and increasing stage-II strain hardening rate (SHR). However, Al11Ce3 weakened the basal texture intensity, reducing the stage-II strain hardening compared to the single-phase Mg alloy investigated earlier. The presence of Al11Ce3 intermetallics delayed the ET nucleation event, which initiates at ε∼0.018. The ET fraction evolves to ∼0.85, lower than in the previous works on single phase Mg alloy. A reduction in the +ve SHR slope could be observed from ε = 0.03 to 0.06, indicating increased slip activities in this portion of stage-II. Beyond ε = 0.1, decreasing stage-III SHR was observed due to basal 〈a〉, and pyr 〈c + a〉-I and II slip activities in the ET orientation. The difference in the compressive behavior along RD and TD could not be observed due to Al11Ce3 precipitate's morphology with elongation along RD. For CD∥to ND, the compressive flow behavior was parabolic with decreasing SHR due to slip-based deformation. ET didn't form, and the texture change was negligible, with initial and final textures having basal texture ∼∥toCD, the geometrically hard orientation.

Anisotropic formability and deformation mechanism of near-α titanium alloy sheet under continuous nonlinear strain paths at high temperature

In the present study, the anisotropic formability and underlying deformation mechanism of near-α TA32 titanium alloy sheet under continuous nonlinear strain paths (CNSPs) at high temperature were investigated in depth. To achieve this goal, a new experimental method combining hot gas bulging with step-combined dies was proposed, and the hot CNSPs of metal sheets can be flexibly and conveniently realized by changing the number and shape of step-combined dies. Based on this method, the anisotropic deformation behavior and forming limits of TA32 sheet under fifteen CNSPs were tested at 800 ℃ with a strain rate of 0.001 s−1. Then, two advanced constitutive models with different scales were embedded into the classical Marciniak-Kuczyński (M-K) theory to predict the forming limits of TA32 sheet under different strain paths: the macro-scale viscoplastic model coupled with Hill48 yield criterion and non-associated flow rule (NAFR) as well as the meso-scale three-dimensional crystal plasticity finite element (CPFE) model coupled with cellular automata (CA). The results demonstrate that the CPFE-CA-MK coupled model exhibits higher accuracy in predicting the forming limits of TA32 sheet under linear and continuous nonlinear strain paths. Especially for the tension-tension strain paths, the CPFE-CA-MK coupled model improves accuracy by at least 3.1 % compared to macro-scale models. Due to the material anisotropy, the initial inclination angle of the groove in the CPFE-CA-MK model is closely related to the strain path and significantly affects the prediction accuracy. Based on the CPFE simulation, the effects of anisotropy and strain path change on the dislocation slip mode of different texture components was analyzed in depth, which provides a theoretical guidance for the optimization of hot forming process of TA32 titanium alloy complex components.

In-situ synchrotron diffraction study on the anisotropic deformation and phase transformation behaviors in NiTi shape memory alloy fabricated by laser powder bed fusion

The stress-induced martensitic transformation (SIMT) and plastic deformation are the crucial factors governing the functional and mechanical properties of polycrystalline NiTi shape memory alloys. This study investigated and compared the SIMT and deformation behaviors along the building direction (BD) and horizontal direction (HD) of NiTi components fabricated by laser powder bed fusion (LPBF), using electron backscatter diffraction (EBSD) and in-situ synchrotron-based X-ray diffraction during uniaxial tension. The experimental results revealed that loading along the HD resulted in both a higher SIMT rate and increased dislocation density compared to the BD of the printed block. Additionally, both HD and BD loadings demonstrated multiple lattice correspondences from the B2-austenite to B19'-martensite phase. The BD sample, with its more complex grain boundary network, densely distributed localized stress and strain, as well as, smaller grain size, contributed to a lower SIMT rate and dislocation density. These findings underscore the impact of crystallographic orientation and microstructural characteristics on the mechanical responses and SIMTs of LPBF-fabricated NiTi alloys.

Experimental and mechanistic investigation on the plastic anisotropic deformation behavior of α-phase titanium alloy Ti-2Al-2.5Zr

Ti-2Al-2.5Zr is widely used in piping and structural support applications, however, the rolling forming process results in anisotropic deformation during service. This behavior has implications for the manufacturing processes and structural safety assessments in engineering applications. In this study, the plastic anisotropic deformation behavior of a rolled Ti-2Al-2.5Zr plate was investigated using uniaxial tensile tests along the transverse, normal, and 45° directions. Acoustic emission, electron backscatter diffraction, and scanning electron microscopy methods were used to investigate dislocation slip and twinning mechanisms. The results indicated that different microscopic deformation mechanisms caused the significant macroscopic anisotropy of Ti-2Al-2.5Zr. The primary mechanisms involved were prismatic <a> slip, pyramidal <c+a> slip, and {10-12} extension twinning. The stress direction determined the influence of each of these mechanisms during the yielding and plastic deformation phases. Application of the visco-plastic self-consistent model established the relationship between the macroscopic mechanical responses and microscopic deformation mechanisms. It was revealed that Ti-2Al-2.5Zr achieved its optimum strength when the initial texture aligned most of the grain c-axis at angles ranging from 30° to 50° relative to the deformation direction. This finding provides a direction for the texture design of Ti-2Al-2.5Zr in engineering materials.

The effect of heat treatment on the anisotropic mechanical properties of metastable β titanium alloy

The effect of heat treatment on the anisotropic mechanical properties of metastable β titanium alloy is investigated in this work. The anisotropic deformation behaviour is mainly due to the formation of band-like macrozone and texture during forging, which can be effectively weakened by solution + aging treatment. Both the microstructure and texture of the heat treated samples are favourable for the lower strength, higher ductility and impact toughness of axis direction (AD) samples than circumferential direction (CD) ones. Besides, the CD impact samples have stronger anisotropy than AD samples. The delamination along different directions happens in the impact fracture surface of CD samples.

Predicting edge fracture in dual-phase steels: Significance of anisotropy-induced localization

While experimental methods for characterizing edge fracture have advanced significantly, current modeling approaches often neglect factors like anisotropy evolution and localization, limiting their ability to accurately predict edge fracture across various tests. In the present study, we investigate the anisotropic deformation, localization, and fracture behavior of a dual-phase (DP1000) steel during hole expansion tests using an advanced evolving anisotropic model coupled with a hybrid damage mechanics model. The anisotropic plasticity model is calibrated by tensile tests along different loading directions and is capable of describing both anisotropic hardening and r-value evolution, while the fracture model is calibrated by tests under several stress states. To illustrate the impact of anisotropy, an isotropic version of the model is also included for comparison. The novelty of the investigation is that it originally found the edge fracture of the DP1000 steel is anisotropic and triggered by through-thickness localization induced by material anisotropy. Therefore, only the model with anisotropy can provide a satisfactory prediction of the hole expansion ratio as well as the location of the edge fracture, while the isotropic model overestimates the experiments significantly. The findings provide an in-depth understanding of the importance of anisotropy in evaluating edge fracture behavior, which not only improves the modeling accuracy but also adds a design concept to enhance the edge formability of materials.

Quasi-in-situ investigation on complete lamellar fragmentation of β-solidified TiAl alloy during uniaxial isothermal compression

The coarse as-cast lamellar microstructure in TiAl alloys is difficult to be broken completely by thermomechanical processing. Some remnant lamellar colonies in the deformed microstructure seriously affect the microstructural homogeneity and deteriorate the properties. In this study, it is found that by isothermal compression at 1230 °C and 1250 °C, the lamellar colonies of Ti-43.5Al-4Nb-1Mo-0.1B (TNM) alloys can be completely broken. This is attributed to the weakened anisotropic deformation behavior of the lamellar colonies due to the isothermal holding treatment before deformation. The deformation behavior at 1230 °C was investigated by quasi-in-situ experiments. It is observed that the regions near lamellar colony boundaries first undergo dynamic recrystallization at small strain, while the lamellar colonies gradually break down with increasing strain. The adequate fragmentation of lamellar colonies mainly depends on the recrystallization of α lamellae (αL). The isothermal holding at 1230 °C leads to an increase in the content and thickness of αL, which allows it to assume more deformation and promotes its recrystallization by reaching critical strain. The interrupted γ lamellae (γL) formed by decomposition during isothermal holding facilitates the occurrence of α recrystallization within the lamellar colonies by hindering dislocation movement. In addition, recrystallized γ grains (γR) are gradually dissolved by the formation of α precipitates inside them through the γ → α phase transformation and the subsequent consumption of α precipitates by the recrystallized α grains.

Anisotropically self-oscillating gels by spatially patterned interpenetrating polymer network.

Here we introduce sub-millimeter self-oscillating gels that undergo the Belousov-Zhabotinsky (BZ) reaction and can anisotropically oscillate like cardiomyocytes. The anisotropically self-oscillating gels in this study were realized by spatially patterning an acrylic acid-based interpenetrating network (AA-IPN). We found that the patterned AA-IPN regions, locally introduced at both ends of the gels through UV photolithography, can constrain the horizontal gel shape deformation during the BZ reaction. In other words, the two AA-IPN regions could act as a physical barrier to prevent isotropic deformation. Furthermore, we controlled the anisotropic deformation behavior during the BZ reaction by varying the concentration of acrylic acid used in the patterning process of the AA-IPN. As a result, a specific directional deformation behavior (66% horizontal/vertical amplitude ratio) was fulfilled, similar to that of cardiomyocytes. Our study can provide a promising insight to fabricating robust gel systems for cardiomyocyte modeling or designing novel autonomous microscale soft actuators.

Fracture Prediction of Aluminum Alloy Sheet AA2024-T3 Using Analytical Stress and Experimental Strain Based Failure Criteria

In this work, the fracture prediction of aluminium alloy sheet, grade AA2024-T3 was investigated using the Fracture Forming Limit Curve (FFLC) and Analytical Fracture Forming Limit Stress Curve (FFLSC) as failure criteria. Initially, the FFLC was experimentally achieved by means of the Nakajima Stretch forming test coupled with GOM strain measurement system, providing the Digital Image Correlation (DIC) technique. Subsequently, the analytical FFLSC was plastically computed using experimental FFLC data combination with Swift hardening model and anisotropic Hill’48 yield model for representing anisotropic plastic deformation behaviour on examined sheet. Finally, Fukui stretch drawing and Three point bending tests were conducted both experiment and numerical simulation to evaluate the fracture state and verifying an applicability of obtained FFLC and FFLSC. In the simulation, the ABAQUS 2017 element deletion function was employed for directly implementing the fracture criteria regarding the FFLC and FFLSC. It was concluded that the analytical FFLSC could more realistically predict fracture behaviour better than the FFLC based on strain. In term of percentage error, the analytical FFLSC generated an error less than the FFLC.

Effect of grain boundary Widmanstätten α colony on the anisotropic tensile properties of directed energy deposited Ti-6Al-4V alloy

Columnar grain structure caused anisotropy in mechanical properties, especially in elongation, is an important concern for Ti-6Al-4 V alloy fabricated by directed energy deposition (DED). Several strategies have been proposed to reduce anisotropy by globularizing the grains, but these conventional approaches are costly and inefficient due to challenges faced during producing the columnar β-grain structures. However, understanding the impact of columnar grain-related microstructures on the anisotropic deformation behavior is still necessary. Despite the recognition of the importance of grain boundary Widmannstätten α colony (αWGB) as a grain-related microstructure, it has received limited attention in available literature on anisotropy in mechanical properties. This study employed in-situ induction heating during DED to control αWGB formation, yielding three Ti-6Al-4 V samples with varying αWGB sizes. Anisotropic deformation of αWGB and its impact on elongation in build and transverse directions were analyzed. αWGB width grew from 0.5 µm to 32.4 µm via diffusion-controlled growth due to reduced cooling rate. Transverse deformation led to dislocation movement and accumulation, causing early failure and worsened ductile anisotropy within αWGB. Notably, larger αWGB size significantly exacerbated anisotropy in ductility. This work underscores αWGB's role in anisotropic deformation and offers insights for optimizing mechanical properties in DED-fabricated titanium alloys.

Anisotropic Deformation Behavior and Indentation Size Effect of Monocrystalline BaF2 Using Nanoindentation.

In this study, our objective is to investigate the anisotropic deformation behavior and the indentation size effect (ISE) of monocrystalline barium fluoride (BaF2) using nanoindentation experiments with a diamond Berkovich indenter. BaF2 is known for its anisotropy, which results in significant variations in its mechanical properties. This anisotropy poses challenges in achieving high processing quality in ultra-precision machining. Through our experiments, we observed numerous pop-in events in the load-displacement curves, indicating the occurrence of plastic deformation in BaF2 crystals, specifically in the (100), (110), and (111) orientations; these pop-in events were observed as the indentation depth increased to 56.9 nm, 58.2 nm, and 57.8 nm, respectively. The hardness-displacement and elastic modulus-displacement curves were obtained from the tests exhibiting the ISE. The nanoindentation hardness of BaF2 is found to be highly dependent on its crystallographic orientation. Similarly, for BaF2 in the (100) orientation, the range is from 2.43 ± 0.74 and 1.24 ± 0.12 GPa. For BaF2 in the (110) orientation, the values range from 2.15 ± 0.66 to 1.18 ± 0.15 GPa. For BaF2 in the (111) orientation, the values range from 2.12 ± 0.53 GPa to 1.19 ± 0.12 GPa. These results highlight the significant influence of crystallographic orientation on the mechanical properties of BaF2. To better understand the ISE, we employed several models including Meyer's law, the Nix-Gao model, the proportional specimen resistance (PSR) model, and the modified PSR (mPSR) model, and compared them with our experimental results. Among these models, the mPSR model demonstrated the best level of correlation (R2>0.9999) with the experimental measurements, providing a reliable description of the ISE observed in BaF2. Our reports provide valuable insights into the anisotropic mechanical characteristics of BaF2 materials and serve as a theoretical guide for the ultra-precision machining of BaF2.

A Molecular Dynamics Study on the Dislocation-Precipitate Interaction in a Nickel Based Superalloy during the Tensile Deformation.

In the present paper, the dislocation-precipitate interaction in the Inconel 718 superalloy is studied by means of molecular dynamics simulation. The atomistic model composed of the ellipsoidal Ni3Nb precipitate (γ″ phase) and the Ni matrix is constructed, and tensile tests on the composite Ni3Nb@Ni system along different loading directions are simulated. The dislocation propagation behaviors in the precipitate interior and at the surface of the precipitate are characterized. The results indicate that the dislocation shearing and bypassing simultaneously occur during plastic deformation. The contact position of the dislocation on the surface of the precipitate could affect the penetration depth of the dislocation. The maximum obstacle size, allowing for the dislocation shearing on the slip planes, is found to be close to 20 nm. The investigation of anisotropic plastic deformation behavior shows that the composite system under the loading direction along the major axis of the precipitate experiences stronger shear strain localizations than that with the loading direction along the minor axis of the precipitate. The precipitate size effect is quantified, indicating that the larger the precipitate, the lower the elastic limit of the flow stress of the composite system. The dislocation accumulations in the precipitate are also examined with the dislocation densities given on specific slip systems. These findings provide atomistic insights into the mechanical behavior of nickel-based superalloys with nano-precipitates.

Formability prediction of high‐strength steel sheet using experimental, analytical and theoretical analysis based on strain and stress forming limit curves and its application to automotive forming parts

AbstractIn this work, the high‐strength steel (HSS) sheet dual‐phase 440 (DP440) were conducted to establish the forming limit curve (FLC) and analytical forming limit stress curve (FLSC) obtained from experimental forming limit curve. First, the Nakajima stretch forming examination was carried out to obtain forming limit curve of investigated sheet. Afterwards, the theoretical Marciniak–Kuczinsky (M–K) model was developed and calculated to evaluate localized necking limits both in strain and stress spaces combination with anisotropic yield criteria. Then, the analytical forming limit stress curves were plastically calculated by using experimental forming limit curve data combination with Swift hardening model and anisotropic yield criteria namely, Hill’48 and Yld2000‐2d for representing anisotropic plastic deformation behavior on examined steel sheet. Finally, automotive stamping parts were performed in order to verify an applicability of all developed curves. It was observed that the analytical forming limit stress curves could more precisely predict the formability of automotive parts better than the forming limit curve based on strain. Particularly, the one based on Yld2000‐2d predict better than the one based on Hill’48. Simultaneously, the experimental forming limit curve and analytical forming limit stress curve were also evaluated comparing with the theoretical calculated forming limit curve and forming limit stress curve using the Marciniak–Kuczinsky model. It should be noted again that the experimental forming limit curve and analytical forming limit stress curve are the best one. Therefore, the Yld2000‐2d yield function better represented the anisotropic behavior of the high‐strength steel sheet dual‐phase 440 than Hill′ 48 yield function, and can suitable be used for the analysis prediction and design of bumper automotive parts under forming processes.

Anisotropic deformation mechanisms of rolling-textured Zircaloy-4 alloy by a crystal plasticity model

This study focuses on investigating the anisotropic deformation behavior of rolling-textured Zircaloy-4 alloy under uniaxial tension along the rolling direction (RD) and transverse direction (TD). A dislocation density-based crystal plasticity finite element method is used to study the associated mechanisms. The simulation accurately reproduces the experimental results on stress–strain curves and strain hardening rate. The relationship between relative activities in different slip systems and anisotropic plastic deformation is established. It is revealed that in the tensile deformation, prismatic slip dominates plastic deformation in the RD, while both prismatic slip and basal slip dominate plastic deformation in the TD. The difference in the dominant slip modes leads to a lower yield stress and a higher strain hardening rate in the RD. Furthermore, the stress and strain distributions in the tensile direction are also statistically analyzed. It is found that a certain proportion of hard grains results in more severe stress concentration and lower uniform elongation in the TD specimen compared with the RD specimen. In addition, the strain rate sensitivity of the yield stress is investigated. It is shown that Zircaloy-4 alloy has almost the same yield anisotropy (TD > RD in terms of the yield stress) at different strain rates in the RD and TD.

Unravelling anisotropic deformation behaviour of Ti-6Al-4V ELI fabricated by powder bed fusion additive manufacturing

The uniaxial compression tests with respect to the different loading directions (i.e., parallel, and perpendicular to the building direction) were performed to investigate the anisotropic deformation mechanism of Ti–6Al–4 V ELI (extra low interstitial) alloy fabricated by laser powder bed fusion (L-PBF). The tests showed anisotropic mechanical properties; the sample loaded perpendicular to the building direction (TDx) has a higher fracture strain and lower yield strength, but a superior hardening effect than those of the sample loaded along the building direction (BD). Electron backscatter diffraction (EBSD) and digital image correlation (DIC) analyses were conducted used at regions of interest (ROI) in as-built and deformed samples. The kernel average misorientation (KAM) analysis revealed that a trend of dislocation evolution is strikingly different according to the loading directions; uniform KAM distribution is observed in the BD sample, whilst localization at prior β grain boundaries is found in the TDx sample. In addition, it was identified via a microscopic strain distribution map that the unique layered microstructure (i.e., layer band) and prior β grain boundary are more sensitive to compressive loading than the surrounding matrix. The layer band and prior β grain boundary were formed with their directivity during the additive manufacturing process; thus, their morphology is different depending on the loading direction. As a result, the layer band and prior β grain boundary play a key role in anisotropic behaviour, more precisely, the anisotropic deformation behaviour originates from the morphology of the layer band and β grain boundary, which is changed with respect to the loading direction.

Experimental study and modelling of anisotropic behaviour of aluminium-lithium alloys in creep age forming

The anisotropic deformation behaviour of the 3rd generation aluminium-lithium (Al-Li) alloys can significantly affect the accuracy of prediction and fabrication, especially for fabricating complex shaped components. To address this challenge and shed light on improving the prediction accuracy with the existence of material anisotropy, this study systemically investigated the anisotropic behaviour during deformation and creep-ageing, and proposed a comprehensive anisotropic material model and its implementation method in the numerical simulation, which was verified with four-point bending creep age forming (CAF) tests. The anisotropic behaviours of the material including yielding, hardening, and creep deformation were investigated with uniaxial tensile and creep-ageing tests adopting specimens cutting along 0°, 15°, 30°, 45°, 70° and 90° to the rolling direction. The yield strengths varied in the range of 378 to 456 MPa for different directions, with the highest and lowest values appearing at 0° and 70°. The creep deformation also showed strong anisotropic behaviour and the accumulated creep strain for 90° (0.52%) was four times larger than the value for 0° (0.11%) under 415 MPa at 143 °C for 5 h An anisotropic material model was established based on the modified non-associated quadratic Hill48 yield function and can adequately capture the observed anisotropic behaviour. An implementation strategy using the bisection method with the map returning scheme was proposed for incorporating the proposed model in numerical simulation. A good agreement was achieved between the predicted and experimental results for four-point bending CAF tests, demonstrating the validity of the proposed anisotropic material model and the implementation method.

Hybrid manufacturing of steel construction parts via arc welding of LPBF-produced and hot-rolled stainless steels

AbstractThe demand for free-form steel structures having improved performances, reducing labour and resource usage is increasing in the construction sector. Structural nodes are some of the most critical regions for steel structures characterised often by large dimensions. These nodes can exploit the geometrical freedom of metal additive manufacturing (MAM) processes. Laser powder bed fusion (LPBF) is arguably the most developed MAM process, which has limitations regarding the size of the parts to be produced. A way to overcome the size limits of LPBF for producing structural nodes while still exploiting its geometrical capacity is producing hybrid components by welding them to traditionally manufactured beams. Such hybrid joints would constitute a complex system from a mechanical design perspective requiring a systematic analysis in order to be certified for structural use. Accordingly, this work studies the mechanical behaviour of hybrid steel components generated by welding LPBF plates and quarto plates made of AISI 316L stainless steel. The work was guided by a case study based on a large steel node, which helped defining the requirements to fill the gap of the international standards. The mechanical characterisation of LPBF-produced plates and quarto plates, as well as the welded hybrid components revealed a maximum of 10% difference between the properties of the differently manufactured plates. Through the digital image correlation (DIC) analyses, the anisotropic deformation behaviour along the LPBF, weld seam, and quarto plate regions have been identified, and the properties after welding did not show relevant modifications. The tests allowed to define that the failure behaviour is mainly governed by interlayer bounds, and a 0.9 safety reduction parameter for considering the reduction of ductility induced by arc welding to LPBF. Finally, design and production suggestions have been provided for a correct evaluation of gross and effective sections of the designed nodes.

A computational framework based on 3D microstructure modelling to predict the mechanical behaviour of polycrystalline materials

In this work, a computational framework is proposed to predict the microstructure sensitive mechanical behaviour of polycrystalline materials i.e., fatigue crack initiation life and anisotropic deformation behaviour. A methodology is developed to generate 3D microstructural RVEs using Laguerre tessellation technique in Abaqus software at a particular location of the component. In any commercial software (Abaqus), the modelling of morphology of 3D polycrystalline microstructures is quite challenging due to the complex geometries of grains, and large number of interfaces or grain boundaries, however it can be achieved efficiently and automatically with the developed methodology. The continuum damage mechanics based elasto-plastic constitutive model is used to predict the microstructure sensitive fatigue crack initiation life of titanium alloy notched specimens. To capture an accurate fatigue response, damage coupled elasto-plastic constitutive equations are implemented via user defined material subroutine UMAT. The predicted fatigue crack initiation lives show good agreement with the experimental data. To further showcase the application of the developed framework, an anisotropic analysis is performed by generating 3D polycrystalline microstructure of β-titanium alloy. The developed methodology enhances the capabilities of commercial software in the field of microstructure modelling of complex problems.

Understanding the anisotropic tensile deformation behavior of commercially pure titanium by experiments and crystal plasticity simulations

Current work reveals the anisotropic tensile deformation mechanisms of commercially pure titanium (CP-Ti) along rolling direction (RD) and transverse direction (TD) by the statistical analysis of electron back scattered diffraction (EBSD) data and crystal plasticity (CP) simulations. The analysis of texture evolution, misorientation angle distribution, in-grain misorientation axis (IGMA) and Schmid factor indicates that the anisotropic tensile deformation behavior is originating from the anisotropic slip modes. Further CP simulation results confirm this conjecture and reveal that the higher fraction of basal slip accommodates the deformation and leads to the lower strain hardening behavior along TD. The lower uniform elongation along TD is caused by the heterogeneous strain distribution in the microstructure as deduced from digital image correlation (DIC) results and kernel average misorientation (KAM) maps.

The microstructure and anisotropic deformation behavior of rapidly solidified ribbon consolidated Mg-Zn-X (X = Y, Gd, Nd) alloys

The paper describes the effect of the alloying elements (Y, Gd, and Nd) on the microstructure and resulting anisotropy of mechanical properties of Mg-Zn-based alloys prepared by the rapidly solidified ribbon consolidation technique. Material processing leads to the formation of a microstructure consisting of ultrafine dynamically recrystallized (DRX) α-Mg grains and worked non-DRX grains. In general, the small average grain size and overall weak texture, caused by the random orientation of small DRX grains, resulted in relatively high yield strength and moderate elongation during both tensile and compressive loading. Moreover, a reverse tension-compression yield asymmetry was achieved in the investigated alloys thanks to the microstructure features of the investigated alloys, namely the presence of different types of precipitates and/or cluster-arranged layers (CALs) of solute atoms-rich stacking faults in the α-Mg matrix.