Schmid Factor Analysis Research Articles

Comparing the Through-Thickness Gradient of the Deformed and Recrystallized Microstructure in Tantalum with Unidirectional and Clock Rolling.

Controlling the microstructure homogeneity is crucial in achieving high quality tantalum (Ta) sputtering targets used in integrated circuit fabrication. Unluckily, traditional rolling easily generates a microstructure gradient along the thickness direction in Ta sheets. The deformation and recrystallization behavior of unidirectional and clock rolled Ta with an 87% strain were therefore systematically compared to investigate whether the change of strain-pass can effectively ameliorate the microstructure gradient along the thickness. Electron backscatter diffraction was used to analyze the misorientation characteristics of the deformed grains. A strong microstructure gradient exists in the unidirectional rolled (UR) sheets. Many microshear bands and well-defined microbands occurred in {111} deformed grains in the UR sheets, especially in the center region, while the grain fragmentation with {111} and {100} orientation in the clock rolled (CR) sheets was more homogenous along the thickness. The kernel average misorientation (KAM) and grain reference orientation deviation-hyper (GROD-Hyper) further confirmed these differences. X-ray line profile analysis (XLPA) indicated that the stored energy distribution was more inhomogeneous in the UR sheets. Schmid factor analysis suggested that the strain path changes due to clock rolling promoted the activation of multiple slip systems in {111} oriented grains. Upon static annealing, homogeneous nucleation combined with a slower grain growth rate resulted in finer and more uniform grain size for the CR sheet. In contrast, a strong recrystallization microstructure-gradient along the thickness formed in the UR sheets, which is attributed to the fact that the higher stored energy and more preferential nucleation sites led to faster recrystallization in the center region, as compared with the surface region. Thus, clock rolling can effectively improve the homogeneity of the through-thickness recrystallization microstructure of Ta sheets.

Quantifying the Resistance to Dislocation Glide in Single Phase FeCrAl Alloy

The resistance to dislocation glide associated with slip systems {110} and {112} in single phase FeCrAl alloy is measured via micromechanical testing in a scanning electronic microscopy at room temperature. Two important factors, the shape and orientation of a pillar, are discussed with respect to the glide resistance and stress-strain response. Maximizing Schmid factor of one specific slip system while minimizing others is recommended in order to diminish obvious dislocations-induced hardening during in situ testing. Apparent Schmid factor analysis is conducted to select grains with preferred orientations. Two types of pillars with conventional cylindrical shape or dog-bone shape are tested under compression to estimate the resistance to dislocation glide and evaluate the effect of pillar shape on the compression stress-strain response. One dog-bone pillar is tested under tension to check the tension-compression isotropy. We find that the shape of a pillar to a smaller extent affects the measured resistance but strongly influences the stress strain response. Cylindrical pillars exhibit apparent hardening associated with early yielding due to stress or strain concentration at contact region, while dog-bone pillars show an obvious yielding and continuous shearing without hardening. The resistance is 220 MPa for slip system {110} and 230 MPa for slip system {112} . Finite element analysis is performed to account for the influence of pillar shape and contact condition on mechanical response. Furthermore, slip transmission across two high-angle grain boundaries is experimentally investigated and discussed with respect to the misorientation and the continuity of slips across GBs.

Effect of initial orientation on dynamic recrystallization of a zirconium alloy during hot deformation

The present study investigated the influence of the initial orientation on the dynamic recrystallization (DRX) behavior of a Zr-1Sn-0.3Nb alloy. A hot-rolled and annealed Zr sheet was compressed along two directions: along the normal direction so that the grains' ⟨c⟩-axis was nearly parallel to the loading direction (0° sample) and along the transverse direction so that the grains' ⟨c⟩-axis was nearly perpendicular to the loading direction (90° sample). The samples were compressed at 700 °C at a strain rate of 1 s−1. The microstructures at different strains were characterized by the electron backscatter diffraction (EBSD) technique, and conventional dislocation analysis using transmission electron microscope (TEM) was performed. A threshold value of grain orientation spread (GOS) equaled to 5° was used to distinguish the dynamically recrystallized grains from the deformed matrix. The results revealed that the DRX behavior strongly depended on the initial orientation. The Schmid factor analysis and TEM observation confirmed that pyramidal ⟨c + a⟩ slip operated from the first stage of deformation in the 0° sample but not in the 90° sample. For the 0° sample, in the early and medium stages of deformation, due to the high stored energy caused by the operation of pyramidal ⟨c + a⟩ slip, DDRX was mainly contributed to the formation of new fine grains. However, in the later stage of deformation, the DRX mechanism changed from DDRX to CDRX. In the 90° sample, although DDRX featured by grain boundary bulging occurred, the main DRX mechanism was CDRX in the whole deformation processing. Moreover, texture induced hardening in the early stage of deformation hides the softening induced by DDRX.

Deformation mechanisms and slip-twin interactions in nanotwinned body-centered cubic iron by molecular dynamics simulations

Deformation mechanisms in nanotwinned face-centered cubic (fcc) materials have been extensively studied due to the successful fabrication of nanotwinned fcc materials and the advance in experimental techniques and atomistic simulations. However, less attention has been paid to nanotwinned body-centered cubic (bcc) materials despite that deformation twinning has been widely observed in bcc materials both in experiments and computer simulations. Here we investigate the mechanical behaviour of nanotwinned Fe with various twin spacing under tensile deformation as a function of the inclination angle between the twin boundaries (TBs) and the loading direction using large scale molecular dynamics simulations. Our simulations reveal that the twin orientation determines the deformation mechanisms of nanotwinned Fe. When the TBs are parallel or inclined by an angle smaller than 20° to the loading direction, the samples fracture in an almost brittle manner. When the TBs are inclined by a medium angle between 20° and 70°, TB migration takes over the role of the main deformation mechanism and two possible pathways accounting for the disappearance of TBs, namely twinning or detwinning are distinguished. When the TBs are inclined by an angle larger than 70° or nearly perpendicular to the loading axis, plastic deformation is dominated by abundant slip-twin interactions. The dynamic transition in deformation mechanisms is discussed based on Schmid factor analysis and generalised planar fault energy. Moreover, we systematically summarise the plausible slip-twin interactions in bcc materials and determine the energy barriers according the Frank rule. The dislocation reactions at the TBs are compared with experimental observations.

Twin-twin interactions and contraction twin formation in an extruded magnesium alloy subjected to an alteration of compressive direction

Twinning and detwinning represent major deformation mechanisms in hexagonal close-packed (hcp) metals. The aim of this study was to identify twin-twin interactions and contraction twin formation in an AZ31 magnesium alloy when the compressive direction was changed from the extrusion direction (ED) to the normal direction (ND) via electron backscatter diffraction (EBSD) and Schmid factor analysis. {101¯2} extension twins of multiple variants were observed after compressive deformation of 4.3% along ED. The detwinning of {101¯2} extension twins occurred along with the formation of {101¯1} and {101¯3} contraction twins, when the compressive direction was changed to ND. The extension twins in some grains almost fully vanished, making the grains back to a twin-free state. A new twin-twin interaction mechanism being different from double twinning (defined as twins within a twin) was identified, due to the impingement of {101¯1} contraction twins nucleated in the matrix grain on a pre-existing {101¯2} extension twin.

Different slip systems controlling crystallographic preferred orientation and intracrystalline deformation of amphibole in mylonites from the Neyriz mantle diapir, Iran

A deformed layered gabbro and a mylonitic gabbro sample from the marginal shear zone of the Neyriz mantle diapir in Iran were analyzed using electron backscatter diffraction (EBSD). Both samples have the common amphibole crystallographic preferred orientation (CPO) in which (100) lies perpendicular to foliation and <001> parallel to lineation. Amphibole grains in the layered gabbro sample have little internal deformation, whereas in the mylonitic gabbro sample the amphibole grains are strongly distorted and contain low angle grain boundaries. There is a subtle change in CPO as a function of grain size in the mylonitic gabbro. Coarse grains (porphyroclasts) have a (100) <001> CPO oriented with the main foliation reference frame whilst fine grains have a (100) <001> CPO oriented with the C′ shear bands. Detailed analysis of porphyroclast distortions and subgrain boundary trace analysis suggests that hard slip systems, most particularly (110) <1–10> control intracrystalline deformation. Schmid factor analysis suggest that these slip systems are not involved in foliation formation but are linked kinematically to C′ shear bands. It is unlikely that the slip systems that control intracrystalline deformation are important in CPO formation. We interpret that subgrain rotation recrystallization lead to grain size reduction and the elongate recrystallized grains were rotated towards the C′ shear bands by grain boundary sliding. This rigid body rotation, possibly in combination with easy slip on (100) <001> are considered the main cause of CPO formation. Amphibole zonation patterns in the layered gabbro sample suggest that oriented growth of amphibole may have contributed to CPO.

The role of strain hardening in the transition from dislocation-mediated to frictional deformation of marbles within the Karakoram Fault Zone, NW India

The onset of frictional failure and potentially seismogenic deformation in carbonate rocks undergoing exhumation within fault zones depends on hardening processes that reduce the efficiency of aseismic dislocation-mediated deformation as temperature decreases. However, few techniques are available for quantitative analysis of dislocation slip system activity and hardening in natural tectonites. Electron backscatter diffraction maps of crystal orientations offer one such approach via determination of Schmid factors, if the palaeostress conditions can be inferred and the critical resolved shear stresses of slip systems are constrained. We analyse calcite marbles deformed in simple shear within the Karakoram Fault Zone, NW India, to quantify changes in slip system activity as the rocks cooled during exhumation. Microstructural evidence demonstrates that between ∼300 °C and 200–250 °C the dominant deformation mechanisms transitioned from dislocation-mediated flow to twinning and frictional failure. However, Schmid factor analysis, considering critical resolved shear stresses for yield of undeformed single crystals, indicates that the fraction of grains with sufficient resolved shear stress for glide apparently increased with decreasing temperature. Misorientation analysis and previous experimental data indicate that strain-dependent work hardening is responsible for this apparent inconsistency and promoted the transition from dislocation-mediated flow to frictional, and potentially seismogenic, deformation.

Crystallographic characters of {11¯22} twin-twin junctions in titanium

contraction twins that are commonly activated in α-titanium interact to each other and form three types of twin–twin junctions (, , TTJs) corresponding to the crystallography of six twin variants (i = 1,2, … , 6). We detected 243 TTJs in rolled pure α-titanium sheets. Electron backscatter diffraction analysis reveals that TTJs are profuse, 79.8% among three types while and TTJs take up 17.7 and 2.5%. Twin transmission does not occur. Consequently, boundaries associated with twin–twin interactions block twin propagation and influence twin growth. We explain structural features of TTJs according to the Schmid factor analysis and the reaction mechanism of twinning dislocations. The knowledge regarding TTJs provides insight for improving the predictive capability of meso/macro-scale crystal plasticity models for hexagonal metals.

Improving joint performance of friction stir welded wrought Mg alloy by controlling non-uniform deformation behavior

Macroscopic non-uniform deformation is usually found in deformed joints of friction sir welded (FSW) wrought Mg alloys, detrimental to the joint performance. In the present work, two kinds of FSW joints with different stirred zone (SZ) structures were generated for extruded AZ31 plates. Comparative studies were conducted aiming to unravel the underline mechanism of the non-uniform deformation and their effect on tensile properties. It was found that the occurrence of non-uniform deformation was associated with the special texture distribution and twinning behavior in the SZ. The shape of concave sub-regions in the SZ coincided with the distribution area of extension twins. Texture evolution showed that consistent lattice rotation occurred across the SZ during tensile process. Schmid factor analysis revealed the role acted by basal slip and extension twinning in sub-regions at various deformation stages. In addition, the non-uniform deformation behavior could be suppressed by modifying the texture distribution through increasing the tool rotation rate, which meanwhile could improve both the tensile strength and ductility of the joints. Digital image correlation measurements provided detailed examination of the actual strain distribution evolved in the joints and demonstrated the dominant contribution of strain localization to the tensile properties.

Observation of non-basal slip in Mg-Y by in situ three-dimensional X-ray diffraction

Mg-5wt%Y extruded alloy showed excellent tensile ductility along the extrusion direction. An in situ tensile test with three-dimensional X-ray diffraction (3DXRD) identified prismatic, basal, and pyramidal <a> slip in different grains during deformation based on the analysis of grain rotation. Ex situ slip trace analysis using electron backscatter diffraction confirms the extensive activation of non-basal slip systems, which can explain the high ductility of this material. Critical resolved shear stress (CRSS) ratios between non-basal slip and basal slip are estimated from Schmid factor analysis.

Microtexture and Nanoindentation of α and β Phases in Ti–6Al–1.5Cr–2.5Mo–0.5Fe–0.3Si Titanium Alloy

Microstructure and nanoindentation of two-phase Ti-6Al-1.5Cr-2.5Mo-0.5Fe-0.3Si titanium alloy fabricated by drawing and subsequent annealing are systematically investigated. We find a strong fiber texture for alpha phase formed during drawing, which is characterized by crystallographic direction of parallel to the drawing direction, yet a weak texture for beta phase, which is mainly consisted of and aligned with the drawing direction. The major texture components for the both phases during recrystallization are similar to those of the drawn state, but the corresponding texture intensities increase. A large number of alpha grains maintain the Burgers relationship with the beta grains for the drawn and annealed states. In the case of the annealed specimen, the mean values of hardness and elastic modulus for alpha phase are found to be 5.79 GPa and 165.22 GPa, respectively, yet are 4.73 GPa and 152.06 GPa, respectively, for the beta phase. Moreover, we also discuss the relation between elemental distribution and nanoindentation for individual phases. The hardness of textured alpha grains undergoes significant change as a function of the crystal orientation, in good agreement with the Schmid factor analysis. In contrast to the hardness, the measured elastic modulus values of alpha phase are less sensitive to the crystal orientation. No obvious change is identified for hardness and elastic modulus for beta grains in that all the beta grains are prone to generate slips.

Nucleation and preferential growth mechanism of recrystallization texture in high purity binary magnesium-rare earth alloys

We investigated the effect of rare-earth element on recrystallization textures using Mg-Ce and Mg-Gd binary alloys at various concentrations of Ce and Gd, and employing electron backscattered diffraction – EBSD technique. Our results indicate that the rare earth element concentration required to noticeably alter recrystallization texture depends primarily on the processing conditions, and cannot be regarded only from the concentration standpoint. Rare earth element additions and stored energy from deformation work in combination to alter texture in rare earth element containing magnesium alloys. The nucleation stage of dynamic recrystallization was explored in samples with partially recrystallized microstructures, revealing necklace structures of small grains forming continuously along the boundaries of pancake-shaped grains in the extrusion direction. Stochastic relaxation of basal a, pyramidal c+a, and prismatic a dislocations into low-angle grain boundaries produced chains of new dynamically recrystallized embryos with nearly random orientations. A remarkable grain-size driven textural transition occurs from a predominant band in the inverse pole figures where the c-axis is oriented 35–65°away from the extrusion direction to a hot spot between 112¯1−112¯3||ED texture components. EBSD observations showed that Mg-Gd alloys have a slower textural transition rate due to the stronger grain refining potential of Gd compared to Ce. These results suggest that the formation of band-like texture patterns in the inverse pole figures is associated with the recovery of basal/c+a dislocations, while transition to a hot spot in texture is a result of preferential grain growth, which was made possible by an effect related to the presence of rare earth elements in the grain boundaries. We investigated the growth behavior during dynamic and static recrystallization. Schmid factor analysis showed a lower net activation of dislocations in 112¯1−112¯3||ED grains compared to 101¯1−101¯2||ED grains. Lower dislocation densities within RE 112¯1−112¯3||ED grains favor their growth by setting the boundary migration direction toward grains with higher dislocation density, thereby decreasing the system energy.

Intracrystalline deformation of garnet, wollastonite and pectolite grains during development of a crenulation cleavage in the sheared skarn

This study focuses on a mylonitic skarn at the margins of a harzburgite of the Neyriz mantle diapir, Iran. The studied sample contained garnet porphyroclasts in a wollastonite and pectolite matrix. The microstructures of porphyroclasts and matrix are analyzed using electron backscatter diffraction (EBSD). Detailed analysis of garnet porphyroclast distortions and subgrain boundary trace analysis suggests that (110) 〈110〉 dislocation control intracrystalline deformation of garnet grains. Wollastonite and pectolite crystallographic preferred orientations (CPOs) are dominated by (100) parallel to foliation plane and 〈010〉 parallel to lineation. However, a dominance of low angle misorientation axes parallel to 〈010〉 precludes 〈010〉 dislocations from significant involvement in intracrystalline deformation. Schmid factor analysis also shows this slip system does not have high integrated Schmid factor. These observations suggest that oriented grain growth may be responsible for wollastonite and pectolite CPO development. Schmid factor analysis suggests (001) 〈100〉 and (100) 〈001〉 slip systems in the wollastonite and pectolite were involved in intracrystalline deformation and are linked kinematically to S2 and reactivated S1 planes.

Sequential [formula omitted] twinning stimulated by other twins in titanium

We experimentally studied sequential {101¯2} twinning in rolled pure titanium at room temperature and identified a new sequential twinning mechanism, i.e., {101¯2} (TiI) extension twin stimulated by the twin-twin junction of two primary {112¯1} extension twins Ti−1II and TiII, which holds a certain relation Ti−1IITiII→TiI. Schmid factor analysis, as the local stress is taken into account, is able to determine the position of sequential twin variant, but cannot determine the twin variant. Displacement gradient accommodation is used to determine the twin variant. The well-known secondary {101¯2} (TjI) extension twins in primary {112¯2} (CiI) contraction twins (referred to as CiI→TjI double twinning) are also analyzed according to a generalized Schmid factor analysis. Displacement gradient accommodation and twin nucleation based on dislocations dissociation only work well for the most active twin variants, but cannot address other phenomena associated with CiI→TjI double twinning. For rarely activated twin variants, displacement gradient accommodation was not satisfied.

Effects of Changes in Test Temperature on Tensile Properties and Notched Vs Fatigue Precracked Toughness of a Zr-Based BMG Composite

Tensile and fracture toughness behavior of a Zr-based bulk metallic glass matrix composite (BMGMC) containing a body-centered cubic crystalline phase was examined over temperatures from 77 K to 653 K (−196 °C to 380 °C). The BMGMC exhibited tensile plasticity at all test temperatures. The sample tested in tension at 173 K (−100 °C) exhibited work hardening but the remaining samples tested at higher temperatures exhibited work softening. EBSD analysis of the crystalline phase after tensile testing provides insight into active deformation mechanisms in the crystalline phase. At 603 K (330 °C), the dendrites exhibit significant plastic strain, with the dendrites oriented {101} parallel to the loading direction exhibiting the least amount of strain. Schmid factor analysis leads to the hypothesis that {110}〈111〉 dislocation mechanisms are active at this temperature. Additionally, measurements of dendrite shape as a function of macroscopic strain state in the tension experiments provide insight into cooperative deformation mechanisms in the composite. At low temperatures, the fracture toughness of the notch toughness samples exceeded that of fatigue precracked samples; but at and above room temperature, the toughness values of notched and fatigue precracked samples converge. These observations are rationalized based on the changes to the flow and fracture behavior of the glass and the crystalline phases over this temperature range. At low temperatures, the crystalline phase is sensitive to defects and changes in stress state that reduce its energy absorbing ability. At higher temperatures, both constituents possess lower strength and are less sensitive to defects, enabling more significant crack tip blunting in the fatigue precracked samples. This produces toughness values that are similar to those obtained for the notched samples.

In situ deformation analysis of Mg in multilayer Mg-steel structures

The deformation modes of Mg in a steel-Mg-steel multilayer composite were studied by step-by-step deformation and EBSD for the same region at 0, 20 and 30% deformation. Texture evolution was characterized using pole figures. The results indicate that the basal texture intensity significantly increases up to 20% deformation. However, from 20% to 30% deformation, activity of prismatic slip increases and the intensity of the overall basal texture is reduced. Shear stress and Schmid factor analysis of the multilayer system showed the probability of prismatic slip increases up to 35% by increasing the stress ratio up to 0.4 and decreases afterwards.

Single and double twin nucleation, growth, and interaction in an extruded magnesium alloy

The objective of this study was to identify twinning characteristics and mechanisms in an extruded AZ31 magnesium alloy under favorable conditions of profuse 101¯2 extension twinning using in-situ optical microscopy, electron backscatter diffraction, and X-ray diffraction analysis. The propagation of a single twin variant led to a relatively fast saturation of twin nucleation after which the increase in strain was predominantly accommodated by the growth of existing twin lamellas. For distinct twin variants, the intersecting twins led to the confinement of the spaces constrained by the fine twin lamellas. Embryonic twin structures acknowledged theoretically or through atomistic simulations were experimentally observed, including the vanishing of primary112¯1 embryonic twin via the nucleation and growth of either single or multiple 101¯2 secondary extension twin variants during deformation. Newly identified twin-twin interaction scenarios included the ladder-like and branching-like twinning structures which occurred depending on the applied strain, incoming twin paths, and their impingement on the pre-existing twin boundaries. The formation of the branching-like structures involved three or more non-co-zone 101¯2 extension twin variants where the activation and growth of one variant among them were found to be favored by the external stresses via Schmid factor analysis.

Dependence of dislocation structure on orientation and slip systems in highly oriented nanotwinned Cu

To explore the correlation between orientation, active slip systems and dislocation structure, highly oriented nanotwinned Cu has been deformed in compression to 2% and 6% strain. The compression directions are 90°, 0° and 45° with respect to the twin boundaries (TBs) of the almost parallel twins. The dislocation structures are analyzed by the two-beam diffraction imaging in a transmission electron microscope and by a Schmid factor analysis. In structures deformed at 90° a high density of long straight dislocation lines with both slip plane and Burgers vectors inclined to the twin plane (slip Mode I) are observed; they transmit across multiple TBs at a strain of 2% and form a high density of dislocations on TBs at a strain of 6%. In structures deformed at 0° dislocations with Burgers vectors parallel to the twin plane (slip Mode II) are confined within Twin/Matrix lamellae and the analysis shows that both slip Mode I and II are active with dominance of Mode II. In structures deformed at 45° dislocations from slip Modes I, II and III are identified, where Mode III dislocations consist of partial dislocations moving along the TBs and full dislocations inside the twin lamellae gliding on the slip planes parallel to the twin plane. The analysis of the dislocation structures illustrate the strong correlation between active slip systems and the dislocation structure and the strong effect of slip mode anisotropy on both the flow stress and strain hardening rate of nanotwinned Cu.

Dislocation mediated variant selection for secondary twinning in compression of pure titanium

By compression along the normal direction of rolled pure titanium sheet, primary {112¯2} type compression twins were observed, followed by secondary {101¯2} extension twins. The latter can be classified into three groups according to their misorientation with respect to the parent matrix grains: 41.34° around <5143¯> (Group I), 48.44° around <5¯503¯> (Group II), and 87.85° around <743¯0> (Group III). The experimental observations revealed the following activity frequency of these groups: Group II is the most frequent followed by Group I, and only a few secondary twins can be seen for Group III. When the classical Schmid factor (SF) analysis is applied, the smallest activity is predicted for Group III, in agreement with the experimental observations. However, the SF based criterion fails to distinguish between Group I and Group II variants. Similarly, the twin-shear accommodation based variant selection model proposed earlier for titanium [Qin and Jonas, Acta Mater. 75 (2014) 198–211] is not effective because the easiest accommodation by prismatic slips favors Group III variants which are nearly absent in the experiment. A possible explanation can be based on the smallest inclination angle of the secondary twinning habit plane with respect to the primary one, proposed by Barnett et al. [Acta Mater. 56 (2008) 5–15] which clearly favors Group II. It cannot make distinction between variants of the same group but can predict the right variants if complemented with the SF criterion. In the present work a new approach is proposed in order to disclose the preference for Group II variant over Group I. It is based on the special twinning geometry that applies to Group II; the intersection line of the primary and secondary twin planes lies in an active prismatic plane in the primary twin. Consequently, dislocation reactions are possible for the selection of secondary twin variant in Group II. Namely, prismatic <a> type dislocations in the primary twin can produce partial dislocations that activate the corresponding secondary twin variant. Nevertheless, a further selection rule has to be applied to choose one out of the two possible Group II variants; this is based on the higher Schmid factor of the two secondary variants. By contrast, pyramidal dislocations would be required for the formation of Group I twins, which is less likely due to their relatively high critical resolved shear stress.

Effect of textural variation and twinning activity on fracture behavior of friction stir welded AZ31 Mg alloy in bending tests

Strong local texture is usually formed in friction stir welded (FSW) Mg alloys and varies in different positions of the weld zone. Textural variation has an impact on fracture behavior and caused a poor mechanical property during the transverse tensile tests. However, due to the different stress and strain state between the inner and outer surfaces, the effect of textural variation on fracture behavior in bending tests is still unknown. The present study aims to investigate the relationship between textural variation, twinning activity and fracture behaviors in bending tests by Schmid factor analysis. It is found that sudden change of texture at the transition zone (TZ)/stir zone (SZ) interface and different twinning activity between the TZ and SZ-side have an impact on fracture behavior of bending samples, especially for crack propagation at the TZ/SZ interface for Surface bending test. The effect of textural variation on fracture behavior in bending is highly dependent on the local stress state and it can be well explained by the calculated Schmid factor in terms of the assumed stress state for bending. The present work is helpful for tailoring the local texture to change fracture behavior and improve the joint strength of FSW Mg welds.