Recrystallization Texture Components Research Articles

Microstructure and Texture Evolution in Cold-Rolled and Annealed Oxygen-Free Copper Sheets.

Commercial oxygen-free copper sheets were cold-rolled with reduction rates ranging from 20% to 87% and annealed at 400, 500 and 600 °C. The microstructure and texture evolution during the cold-rolling and annealing processes were studied using optical microscopy (OM), scanning electron microscopy (SEM) and electron back-scattered diffraction (EBSD). The results show that the deformation textures of {123}<634> (S), {112}<111> (Copper) and {110}<112> (Brass) were continuously enhanced with the increase in cold-rolling reduction. The orientations along the α-oriented fiber converged towards Brass, and the orientation density of β fiber obviously increased when the rolling reduction exceeded 60%. The recrystallization texture was significantly affected by the cold-rolling reduction. After 60% cold-rolling reduction, Copper and S texture components gradually decreased, and the {011}<511> recrystallization texture component formed with the increase in annealing temperature. After 87% cold-rolling reduction, a strong Cube texture formed, and other textures were inhibited with the increase in annealing temperature. The strong Brass and S deformation texture was conducive to the formation of a strong Cube annealing texture. The density of the annealing twin boundary decreased with the increase in annealing temperature, and more annealing twin boundaries formed in the oxygen-free copper sheets with the increase in cold-rolling reduction.

Effect of initial grain size on the recrystallization behavior and recrystallization texture of a Mg–3Gd alloy

The effect of initial grain size on the recrystallization and recrystallization texture of a rolled Mg–3Gd (wt.%) alloy is studied in detail. The results show that the deformation microstructure of an initially coarse-grained (CG) sample has a larger twinned area and a higher density of twin boundaries than a fine-grained (FG) sample. After annealing, the CG sample recrystallizes preferentially in the twinned area, whereas the FG sample adopts the higher density grain boundaries as the nucleation sites. Furthermore, weak recrystallization texture components appear from the grain nucleation stage, regardless of the initial grain size, and are preserved after complete recrystallization due to uniform grain growth. The majority of recrystallization texture is deviated 20°–45° away from normal direction (ND), accounting for more than 50 %. Especially, the recrystallization texture of the FG sample is a “Rare Earth texture”, in contrast to the widely reported texture modification unrelated to grain boundary nucleation. Only a scattered basal texture is observed in the CG sample, which also differs from the reported “Rare Earth texture” originating from shear band nucleation in dilute Mg–Gd alloys. Finally, based on the Johnson–Mehl–Avrami–Kolmogorov (JMAK) model, the recrystallization kinetics are calculated, and it is found that the initial grain size mainly affects the nucleation rate, and has limited effect on the grain growth rate.

Effect of initial heat treatment of A390 alloy on microstructure and tribological behavior of friction surfaced coating

In this study, the effect of the A390 alloy consumable rod's three preprocessing heat treatment conditions (homogenization, solid solution, and artificial aging treatment) on the microstructural evolution, mechanical properties, and wear resistance of the friction surfaced coating applied on a commercially pure aluminum alloy substrate was investigated. The results showed that friction surfacing using artificially aged and solid solution-treated consumable rods results in minimum (3.45 ± 0.35 μm) and maximum (5.63 ± 0.25 μm) coating grain sizes, respectively. Friction surfacing using artificially aged treated consumable rods results in smaller, more uniformly distributed Si particles in the coating microstructure. The [111] and [101] directions of most grains in the consumable rod and coating are parallel to the consumable rod axial axis and surfacing direction, respectively. Recrystallization texture components, including Goss and Cube-Twin, are observed in coatings. Compared to the other consumable rods, the coatings fabricated using artificially aged treated consumable rod result in highest hardness (117.62 ± 9.58 HV0.1), maximum bond strength (13.98 ± 1.02 kN), and lowest wear rate (5.6 ± 0.8 μg/m).

Evolution of recrystallization texture in medium to low stacking fault energy alloys: Experiments and simulations

The present work aims to investigate the evolution of static recrystallization microstructure and texture in medium to low stacking fault energy (SFE) alloys. In these categories of materials, the process of recrystallization becomes complex because of the presence of extensive deformation heterogeneity. Ni-xCo (40 and 60wt.% Co) alloy has been chosen for this purpose, where Ni-40Co belongs to medium SFE, and Ni-60Co belongs to low SFE regimes. The effect of solid solution strengthening and deformed microstructural features on the mechanism of recrystallization are explored. Both the alloys were subjected to 50% cold-rolling reduction followed by isothermal annealing at 600°C. Recrystallization texture of Ni-40Co shows a non-uniform α-fiber having a peak intensity at the Goss component, whereas Ni-60Co shows uniform α-fiber texture. Both the alloys also show rotated cube (Rt C) and rotated Cu (Rt Cu) components after recrystallization. Apart from that Ni-60Co exhibits brass recrystallization (BR) texture component. The differences in the recrystallization texture in both the Ni-Co alloys are attributed to the role of different heterogeneous deformation features in the microstructure and transition from Cu-type to Bs-type as-deformed texture. The recrystallization microstructure is dominated by the formation of substantial annealing twin (Σ3) boundaries, which also produces many new orientations; thereby weaken the recrystallization texture. These experimental findings and the proposed mechanism were used as input to simulate the recrystallization microstructure and texture in the alloy using the parallelized cellular automata (CA) technique. Parallelized CA model has successfully predicted the evolution of recrystallization texture and microstructure through simulation except parallel annealing twin feature.

The influence of deformation texture on nucleation and growth of cube grains in aluminium

The influence of deformation texture on the initial stages of recrystallization of deformed pure Al single crystals and commercial AA1050 alloy were characterized. To precisely quantify the orientation relationship between nuclei and simple deformation structures, single crystalline samples of stable Br(110) [1-1-2] and semi-stable S’(234) [20-28 11] orientations, were plane strain compressed (PSC) to 40% to develop a dominant homogeneous microstructure composed of two sets of microbands. The samples were then lightly annealed to reach the initial stage of primary recrystallization. The results on single crystals were related to the behaviour of the polycrystalline samples in state after hot-rolling then PSC to the same degree and lightly annealed. SEM/EBSD analyses of single crystalline samples demonstrate that the orientations of recrystallized grains are limited to a certain number of orientation groups. However, the orientations of the as-deformed state are not retained in the orientations of new grains. Deformed samples with Br orientation do not show the formation of cube grains during recrystallization, whereas strong nucleation of cube-oriented grains is observed in homogeneously and heterogeneously deformed areas in the semi-stable S’ orientation, despite the cube-oriented nuclei not present in the as-deformed structure. The recrystallization texture components of the AA1050 alloy were related to the standard β-fibre texture formed during the previous cold deformation. Cube grains formed intensively in PSC polycrystalline samples, primarily in association with as-deformed areas with near four variants of S(124) [21-1] and S’ orientations and were characterized by local misorientations around the <111> axes.

Comparison of a copper processed by asymmetric unidirectional rolling (AUR) and cross rolling (ACR): Strain distribution, microstructure, texture, and mechanical properties

In this work, the effect of strain path on the strain distribution, microstructural evolution, crystallographic texture, and mechanical behavior of electrolytic tough-pitch copper was investigated by simulation and experimental procedures. The asymmetric unidirectional and cross rolling processes with a thickness reduction of 90% were performed at room temperature. The asymmetric cross-rolling (ACR) gives much better through-thickness uniformity of shear strain distribution compared to the asymmetric unidirectional-rolling (AUR). The average equivalent strain of AUR and ACR after 90% rolling reduction was 3.99 ± 1.22 and 3.66 ± 0.26, respectively. Both AUR and ACR processes improved the particle distribution in the matrix. However, the particle distribution of the AUR sample was slightly more uniform compared to the ACR sample. The shape of primary grains in the AUR copper was straight while that in the ACR sample was zigzag. The average dislocation density of the AUR sheet was larger than that of the ACR sample (2.41 × 1016 m−2 vs. 2.31 × 1016 m−2). The major recrystallization mechanism in the AUR and ACR samples was discontinuous and continuous dynamic recrystallization, respectively. The main deformation textures (Copper, S, and Brass components, and α and β fibers) were weak in both samples due to the domination of recrystallization and shear textures in the cold-rolled copper. The recrystallization texture components in the upper region were stronger than in the lower region. The uniformity of the microhardness profile of the ACR sample was more than that of the AUR sample. The AUR sample had a larger strength and a smaller ductility compared to the ACR sample. The results showed that the strain path of asymmetric rolling was effective on the strain-hardening behavior of copper during the tensile test. The fractograph of the ACR sheet exhibited ductile dimples. However, the fractograph of the AUR sample revealed many ductile shear dimples and flat surfaces.

Comparison of microstructural, texture and mechanical properties of SiC and Zn particle reinforced FSW 6061-T6 aluminium alloy

This work investigates the microstructure, mechanical characteristics, and texture evolution of friction stir welding (FSW) of AA6061-T6 metal matrix composites (MMCs) reinforced with silicon carbide (SiC) and zinc (Zn) particles. The SZ region of the SiC and Zn particle-reinforced aluminium matrix (Al-matrix) composites has ultra-fine grain refinements of 4.79 and 4.18 μm, respectively, compared to base metal (BM) particle sizes of 44.97 μm. Ultra-fine grain refinement in the SZ zone produces dynamic recrystallization with particulate-driven nucleation, Zenner Hollomon, and homogeneous SiC/Zn particle distribution in the Al-matrix. Recrystallization texture components P {011} <112>, cube {001} <101>, rotating cube (H) {001} <110>, and F {111} <112>, along with primary shear texture components (B/B¯, and C), suggested DRX at the joint interface in the SiC-reinforced Al-matrix composite. However, the Zn-reinforced Al-matrix composite has a high plain strain, recrystallization, and deformation texture components of copper {112} <111>, Brass {011} <211>, cube {001} <101>, Goss {110}, and P 011 <112>, and major shear texture components (B/B¯ and C). SiC and Zn-reinforced Al-matrix composites have 110 ± 4 and 120 ± 5 HV0.2 average microhardness, respectively. Also, SiC and Zn-reinforced Al-matrix composites have 224 and 236 MPa tensile strengths, respectively.

Effect of annealing twins, strain-recrystallization processing and δ-phase fraction on microtexture and evaluation of mechanical properties of nickel-based superalloy 718

The Nickel-based superalloy 718 is a precipitation-hardened material, especially by the ordered and coherent phases γ” (Ni3Nb) and γ″ (Ni3 (Al, Ti)). In addition to these phases, precipitation of carbides and δ-phase is possible. This material has high strength, creep, and corrosion resistance at temperatures up to 650 °C. However, despite the alloy’s outstanding performance under harsh environments, research effort has been put into optimizing its properties and increasing the operation temperature. Manipulation of microstructural parameters such as grain boundary character distribution (GBCD), microtexture, second phase fraction, etc. is frequently betaken in order ot achieve better properties. In this context, this work aimed to assess the influence of Thermomechanical Processing on the recrystallization texture of the material and its influence on the alloy’s mechanical behavior. The material was submitted to four iterative processing routes, composed of deformation-heat treatment cycles. The alloy’s microtexture data were obtained through the Electron Backscattered Diffraction technique. Data processing was performed using the MTEX toolbox, where Orientation Density Functions were obtained for microtexture analysis. It was observed that the deformation imposed during thermomechanical processing significantly affects the recrystallization texture of the material so that smaller deformations induce the formation of typical recrystallization texture components; on the other hand, high degrees of deformation lead to a retained deformation texture after annealing. Mechanical properties were evaluated by depicting the influence of different strengthening mechanisms and δ-phase fraction on yield strength and ductility, respectively. It was observed that the main strengthening parameters for the alloy were grain boundaries and intrinsic resistance (Pierls-Nabarro and solid solution), meanwhile ductility was greatly influenced by δ-phase and ∑3n boundaries fractions.

An investigation into the reverse transformation of ferrite to austenite during friction stir processing of a duplex low-density steel

The reverse transformation of ferrite-to-austenite during friction stir processing of a duplex lightweight steel resulted in an abrupt decrease of the ferrite volume fraction within the stirred zone. This was explained in terms of diffusion-governed phenomena from the thermodynamic points of view. However, owing to the recorded thermal history of the process and the low exposure time at the maximum temperature, the probability of shear assisted diffusion was considered. The fraction of high angle and low angle boundaries within the stirred zone was extremely higher than those observed in thermomechanically affected zone or heat affected zone. These high/low angle boundaries acted as preferred diffusion paths and provided a proper condition to increase the lattice diffusion. The results of electron probe micro-analysis indicated that the alloying elements remained relatively un-partitioned in long range order. In addition, the grains were arbitrarily sheared towards the shear surface/ direction and volume fraction of shear texture component was substantially higher than that of recrystallization texture component. The above observations suggest that the abrupt drop in the ferrite content at the vicinity of the rotating tool in the shear layer may be also induced by shear assisted massive transformation.

Stability and deviations from the cube texture during rolling and annealing of Ni foil

Formation of the {100}<001> cube texture component has been reported extensively in many heavily deformed face-centered cubic (FCC) metals and alloys after annealing. The present study shows how to avoid the formation of strong cube texture on the surface of high-temperature annealed Ni foils subjected to large rolling reductions and also retain the high intensity of twin boundaries. The evolution of the surface texture of rolled and annealed foils are discussed in comparison to conventional rolling, shear, and recrystallization texture components. The stability of the cube and ND-rotated cube components in rolled foils are elaborated. In spite of discontinuous recrystallization mechanisms, a high fraction of rolling texture components is retained after annealing. Suppression of the cube component after annealing has been attributed to the constricted-annealing process and possible activation of low-energy twin boundaries. Annealing twins were found to form during the recrystallization process via a growth fault mechanism.

Microstructure, texture, and mechanical properties correlation of AA5083/AA6061/SiC composite fabricated by FSAM process

The current study deals with the effect of silicon carbide (SiC) particle reinforcement on the microstructure, texture evolution, and mechanical properties of the AA5083-O/AA6061-T6 build fabricated using the friction stir additive manufacturing (FSAM) process. The stir zone (SZ) of particle reinforced build shows ultra-fine grain refinement (av. size of 4.22 μm) in comparison to AA5083 (41 μm) and AA6061 (43 μm) base metals. The extent of grain refinement is possible due to the uniform dispersion of SiC particles in the matrix accompanied by dynamic recrystallization (DRX) driven by particle-stimulated nucleation (PSN) and the Zener-Holloman mechanism. Weak texture intensities were visible for both reinforced/unreinforced cases due to reheating and re-stirring action at the joint interface. Major shear texture components (B/ B‾, and C) with the presence of recrystallization texture components cube {001} <101>, P {011} <112>, rotated cube (H) {001} <110> and F {111} <112> were noted in SiC reinforced build, suggesting the DRX at the joint interface. SZ of SiC reinforced build consists of an average microhardness of 116 ±4HV0.1 which is 1.2 times higher than the average microhardness of unreinforced build (96 ±3HV0.1). The maximum strength of 291 MPa was noted for AA5083/AA6061/SiC composite, which is appreciably higher than the unreinforced case (197 MPa).

Effect of intermediate annealing and reduction ratio on the texture evolution and formability in AA5083

In the present study, the effect that intermediate annealing (IA) and reduction ratio (RR) exert on the microstructure and texture evolution in AA5083 sheets was investigated. The initial hot-rolled AA5083 sheet was subjected to the following thermomechanical process: primary cold rolling (CR-1) → intermediate annealing (IA) → secondary cold rolling (CR-2) → final annealing (FA). A reference (Ref) specimen was subjected only to CR-1 → CR-2 → FA with no IA process. Through-thickness microstructural heterogeneities were observed in the initial hot-rolled AA5083 sheet, and these features persisted in the CR-1 and IA specimens. The CR-2 and FA specimens, however, showed no through-thickness heterogeneities. Cold rolling enhanced the plane-strain texture components (Copper, Brass and S) whereas annealing enhanced the recrystallization texture components (Cube and ND-Rotated-Cube (RC)). Following FA, the non-IA (Ref) specimen showed a larger fraction of Cube and ND-RC components by comparison with specimens that had undergone IA. When the r-values predicted using the visco-plastic self-consistent (VPSC) model were compared with the experimental results, the r-value for the non-IA (Ref) specimen was smaller than those for the IA specimens after FA. The average r-value increased gradually (in a 45° direction) as the RR of CR-2 was decreased (70–40%). Controlling the RR of the CR-2 after IA resulted in isotropic sheets with enhanced formability. The largest r-value was observed in FA specimens with a small RR during CR-2. A balance between retaining deformation texture and the evolvement of the Cube component was responsible for the larger r-value.

Plastic Behavior and Microstructure Heterogeneity of an AA6063-T6 Aluminum Alloy Processed by Symmetric and Asymmetric Rolling

Rolling is one of the most employed industrial processes which can be used at multiple manufacturing stages, allowing different geometries such as plates, rods, profiles, billets, slabs, tubes, and seamless tubes to be obtained. However, rolled products develop anisotropy due to the preferential orientation of crystals in the rolling direction. Thus, some process configurations and different processing parameters (e.g., thickness reduction per rolling pass, deformation routes, roll diameters, and strain rate) have been proposed to deal with the desired anisotropy. In this context, this investigation evaluates and compares the effect of symmetrical and asymmetrical rolling on an aluminum alloy sheet deformed until a 38% thickness reduction using multiple rolling passes. The asymmetrical process displayed larger texture and microstructure gradients across the sheet thickness than the symmetrical one, manifested as more grain refinement and more intense shear texture components close to sheet surfaces. In terms of plastic anisotropy, the visco-plastic self-consistent model predicted higher average anisotropy for the symmetric rolling than the asymmetric process due to a strong combination of recrystallization and deformation texture components. Conversely, the asymmetric process showed lower planar anisotropy values due to the increase in the fraction of shear and deformation texture components near the sheet surfaces, producing a less intense overall texture than the symmetric rolling. The additional shear strain component was mainly responsible for the material strengthening and texture weakening after the asymmetrical rolling process. In addition, the shear strain produced grain refinement, decreased misorientation, and higher dislocation densities than the as-received and symmetrically rolled materials. After asymmetrical rolling, the microstructure and texture showed heterogeneous profiles across the sheet thickness. This gave rise to a heterogeneous grain size refinement, decreased misorientation close to sheet edges, and plastic gradients.

Influence of Plug Rotational Speed on Microstructure and Texture of the Recrystallized Zone of a Friction Plug Weld Joint for AA6082-T6.

Experiments of friction plug weld AA6082-T6 aluminum alloy hole defects were carried out by using the method of friction auxiliary heating between the shaft shoulder and base metal. The grain refinement of the joint’s re-crystallized zone was significant, and there was obvious preferred orientation. Under the condition of other constant parameters, the rotational speed of the plug increases as the grain size of RZ increases and the component of High Angle Grain Boundaries decreases. The effect of a high deformation rate on dynamic re-crystallization is greater than that of high deformation temperature. The deformation texture component increased from 1600 r/min to 2000 r/min, while the re-crystallization texture component increased first and then decreased.

Influence of Strain Rate Sensitivity on Cube Texture Evolution in Aluminium Alloys

The influence of strain rate sensitivity on development of Cube texture and on the morphology of Cube-oriented grains is often neglected in simulations approaches. Therefore, crystal plasticity simulations and experiments were performed up to 73 pct of thickness reduction for cold rolling on Al 6016. It is found, that low values of strain rate sensitivity promote Cube grains fragmentation and avoid formation of transition bands already at 50 to 55 pct thickness reduction. High values of strain-rate sensitivity cause formation of Cube transition bands leaving thin Cube grains in the microstructure and delay their fragmentation. Other texture components are affected by changes in strain rate sensitivity as well. The Copper volume fraction in the final texture diminishes as the strain rate sensitivity decreases, while Brass and S components of the beta fiber show a moderately higher volume fraction when the strain rate sensitivity increases. The final volume fraction of Goss is highest when the strain rate sensitivity is 10−2 but low if the strain rate sensitivity is 10−3 or raises up to 10−1. Recrystallization texture components (P, Q) are not affected by strain rate sensitivity, while the invGoss fraction decreases for high values of strain rate sensitivity. The results found in cold rolling crystal plasticity simulations were compared with experimentally determined Cube distribution and texture components obtained through thickness for Al6016 rolled at 80 m/min and 600 m/min. Further crystal plasticity simulations were performed to predict the influence of strain rate sensitivity during several hot rolling conditions where activity of non-octahedral slip systems was included in the simulations. During hot rolling, high values of strain rate sensitivity contribute to Cube stabilization and promote formation of Copper texture and delay Brass and S.

On online texture quality control and management of continuous processes for the production of non-ferrous sheets

The results of the studies of the connection of texture parameters and the quality characteristics of commercial batches of the finally rolled or finally annealed tape made of fcc- materials, which differ in the value of stacking fault energy, phase composition and processing technology are considered. Strips of brass L68 and L63 containing ~62.5 and ~64% of copper and aluminum alloy AMg2 were hot rolled from ingots that were cast in water-cooled and electromagnetic casting mould respectively. Cold rolling was carried out with intermediate annealing to the state of complete recrystallization in the resistance heating furnace (AMg2) or in the induction annealing line (brass) to the finite thickness: ~0.3 mm (AMg2) and 0.6&ndash;1.0 mm (brass), varying the degree of the finite plastic deformation. During the final annealing of the brass strip in the line of induction annealing and etching, the speed was varied. The tape was tested for breaking, Vickers hardness number, cutting-out and draw-forming of &ldquo;glasses&rdquo; in the combination die. In particular, we controlled the characteristics of the anisotropy of plastic properties, the magnitude of the relative earing and intensity 200 and 220 lines of the texture on the general purpose diffractometers in Fe Karadiation by the Schulz reflection method. The texture parameters T and Т, expressing the ratio of the components of the recrystallization texture and the rolling texture of fcc-materials, were determined. It was found that the accuracy of texture control during annealing of brass L63 rolled products using the same texture parameters is reduced in comparison with materials with high stacking fault energy due to the small fraction of {100} &lt;hkl&gt; recrystallization texture component and the dependence of the structure and phase ratio on small, 1.5% for copper, fluctuations in the chemical composition. At the same time, it remains high enough to control the process of organizing feedback when managing the process online. That is, texture control can be extended to annealing materials with very low stacking fault energy, which contain the second phase. At the same time, there are serious restrictions on the degree of deformation during rolling and on the annealing regimes, in which it is reasonable to use the texture control, as well as the absolute need to determine regression dependences of the properties on the texture when changing the technological processing scheme. In each individual case, the necessary condition for organizing the texture control is the presence of the &ldquo;close&rdquo; correlation between the texture parameter and the controlled characteristic. The proposed structural scheme of the texture control during rolling is discussed.The authors gratefully acknowledge S. G. Khayutin, Doctor of Technical Sciences, a founder of a texture control research area in Russia, globally pione ering in texture control of mechanical properties, taking part in acquiring some experimental data used in the research paper, and giving important recommendations at the initial stage of preparing the presented paper.

Asymmetrical superelastic behavior of thermomechanically processed semi-equiatomic NiTi alloy in tensile and compressive modes of deformation

In the present work two different cold working and annealing schemes were utilized, and the asymmetric superelastic response of thermomechanically processed materials were then assessed through cyclic tensile and compressive modes of deformation. The values of transformation stress, transformation strain, and pseudoelastic strain were measured for each treated and solutionized specimens and the asymmetric response was compared. In the solution annealed state, the difference of these parameters at different deformation modes was negligible due to the weak texture of the material, while for thermomechanically treated ones, development of specific deformation and recrystallization texture components was identified to be one of the underlying reasons of intensified asymmetry. The evolved substructure during the thermomechanical processing also played a substantial role in determining the asymmetric response. The presence of fine grains and dense dislocation substructure could hinder the movement of the transformation front, thus limiting the range of transformation. In tensile mode, the transformation stress was lower, but higher transformation strain was achieved, which was discussed relying on the slip activity in specified oriented grains. The lower transformation strain in compression mode led to lower pseudoelastic strain due to the narrow transformation range which finally degraded superelastic response of the material.

Effect of second-phase particle evolution in a twin-roll-casted Al-Mg-Si alloy on recrystallization texture and mechanical anisotropy

In this study, the evolution of second-phase particles in a twin-roll-casted (TRC) Al-Mg-Si alloy is analyzed, and the influence of this evolution on recrystallization texture and mechanical anisotropy is investigated. Based on the obtained results, homogenization significantly affects second-phase particles by promoting dissolution of Mg2Si phases, transformation of the Fe-rich intermetallic phase, and precipitation of AlMgSi dispersoids. During TRC and homogenization, different distributions of second-phase particles (coarse intermetallic phases and fine dispersoids) are achieved. These distributions control the recrystallization texture intensity and components and have a great impact on mechanical anisotropy. For example, the TRC sheet that has a large number of coarse intermetallic particles is characterized by very weak Cube-ND {001} 〈310〉 texture. This sheet has the highest average normal anisotropy r (0.71) and lowest planar anisotropy ∆r (0.077) among the investigated samples. Compared to the non-homogenized sheet, the homogenized counterparts exhibit enhanced texture intensity due to the dissolution or transformation of the intermetallic phase and increase in the number of fine dispersoids. Moreover, the main texture component in these sheets gradually changes to Cube {001} 〈100〉 orientation. To improve the application prospects of the TRC Al-Mg-Si alloy, further studies must be conducted regarding the effects of alloy designing and short process optimization on the material.

Microstructure and texture evolution of TB8 titanium alloys during hot compression

In this study, microstructure and texture evolution of TB8 titanium alloys during hot deformation were investigated by using electron back-scattered diffraction (EBSD) analysis. The results showed that dynamic recrystallization (DRX) behavior of TB8 titanium alloys was drastically sensitive to the strain. As the true strain raised from 0.2 to 0.8, the degree of DRX gradually increased. The nucleation mechanism of recrystallization was observed, including discontinuous dynamic recrystallization (DDRX) resulting from the bulging of original boundaries. Furthermore, continuous dynamic recrystallization (CDRX) occurred because of the transformation of low-angle grain boundaries (LAGBs) to high-angle grain boundaries (HAGBs) in the interior of the original deformed grains. The texture evolution of TB8 titanium alloy during hot deformation process was analyzed in detail, and five texture components were observed, including {001} $$\left\langle { 100} \right\rangle$$ , {011} $$\left\langle { 100} \right\rangle$$ , {112} $$\left\langle { 1 10} \right\rangle$$ , {111} $$\left\langle { 1 10} \right\rangle$$ , and {111} $$\left\langle { 1 1 2} \right\rangle$$ . As the true strain increased, deformation textures were gradually weakened due to an increase in the volume fraction of DRX grains. When the true strain was 0.8, the main texture components consisted of the recrystallization texture components of the {001} $$\left\langle { 100} \right\rangle$$ and {011} $$\left\langle { 100} \right\rangle$$ textures.

Creep Deformation and Dynamic Grain Growth in an Interstitial-Free Steel

Dynamic grain growth is demonstrated to be much faster than static grain growth in a body-centered-cubic, interstitial-free steel sheet material at 850 $$\,^\circ {\rm{C}}$$ . Dynamic grain growth occurs during concurrent plastic deformation at elevated temperature, whereas static grain growth occurs during static annealing. Grain growth during steady-state plastic flow in tension at 850 $$\,^\circ {\rm{C}}$$ to a true strain of 0.2 at a true-strain rate of $$10^{-4}$$ $${\rm{s}}^{-1}$$ doubled grain size, while static annealing for the same time produced no increase in grain size. This is described as dynamic normal grain growth (DNGG) because no abnormally large grains were observed. The recrystallized microstructure of the steel demonstrated a log-normal distribution of grain sizes. DNGG produced bimodal grain size distributions that deviate from the theoretical expectation of a simple shift to larger sizes during normal growth. The bimodal distributions contained a remnant of small grains that were not consumed during grain growth. DNGG produced a crystallographic texture that is unique from both the recrystallized material and that produced by lattice rotation alone. DNGG strengthened the $$\{111\} \langle 110 \rangle $$ and $$\{111\} \langle 112 \rangle $$ components of the strong $$\gamma $$ -fiber component in the original recrystallization texture. Lattice rotation from tensile deformation, by contrast, strengthened the $$\alpha $$ -fiber components that intersect the original $$\gamma $$ -fiber.