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In this work, we present the characterization of Ti sheathed MgB $_2$ wires prepared by PIT with two different cross-sections: circular and hexagonal. We determined the crystallographic texture of both the Ti sheath and the MgB $_2$ core by X-ray diffraction (XRD) pole figures. We evaluated the critical current density ( $J_c$ ) of the wires in two different directions using a SQUID magnetometer, in order to determine the anisotropic factor of the current density ( $J_{af}$ ). We found that $J_{af}$ is larger than one and it is field independent for both wires, consistently with the increased probability to encounter the basal planes perpendicular to the axial direction ( $AD$ ) obtained in the crystallographic texture.

Hagihara K., Nakano T.. Control of Anisotropic Crystallographic Texture in Powder Bed Fusion Additive Manufacturing of Metals and Ceramics—A Review. JOM, https://doi.org/10.1007/s11837-021-04966-7., Additive manufacturing (AM) enables the production of complex, net-shape geometries. Additionally, in AM of metal and ceramics, which has received less attention, the microstructure and texture of the product can be arbitrarily controlled by selecting appropriate process parameters, thereby enabling unprecedented superior properties. This paper discusses recent progress pertaining to texture evolution mechanisms and control methods, with an emphasis on selective laser melting. One of the unique characteristics of AM is that the texture can be varied as a function of position within the product by controlling the scan strategy. The transient behavior of the texture and the factor used to control it via the scan strategy are discussed. In addition, the texture evolution behavior of face- and body-centered cubic as well as noncubic materials is discussed. The importance of the crystallographic “multiplicity” of the preferential crystal growth direction is described to understand the evolution behavior of the texture in such materials.

Inherent brittleness and low mechanical reliability usually inhibit the application of ceramic materials in many structural applications. In this work, we demonstrate that integrating crystallographic texture and second-phase toughening strategies can effectively improve fracture resistance and mechanical reliability in alumina multilayer composites. Composites consisted of equiaxed (1-x)Al2O3-xZrO2 and highly [0001]-textured Al2O3 layers were fabricated, and effects of ZrO2 amount on fracture behavior and mechanical properties of the composites were studied. Increasing ZrO2 amount x results in larger thermal expansion difference between equiaxed and textured layers. The composites with equiaxed layers containing 30 vol% ZrO2 exhibit high apparent fracture toughness Kapt, c ~11.7 MPa·m1/2 and work of fracture γWOF ~1540 J/m2, which correspond respectively to about 260% and 410% enhancements relative to those without ZrO2 addition. Moreover, adding ZrO2 remarkably reduces sensitivity of failure stress to flaw size in the multilayer composites, and the failure stress substantially increases with increasing ZrO2 content. The greatly enhanced mechanical performance achieved here can be mainly attributed to higher magnitude of compressive stresses, more crack bifurcations and longer crack deflection paths within the textured layers. This work can provide important guidelines for developing novel “bio-inspired” materials with improved fracture resistance and flaw tolerance behavior.

The laser powder bed fusion (LPBF) of pure tungsten for the fabrication of near-fully dense components is challenging owing to the intrinsic properties of tungsten. In this study, routine, gas-atomized, and plasma-processed tungsten powder samples were characterized for their powder shape, size distribution, tapped density, and flowability, and then used to fabricate parts using identical LPBF process parameters to evaluate the influence of the powder characteristics on the metal densification and microstructure. The plasma-processed W powder showed a relative density of 98.7%, the highest value yet to be reported, at a baseplate temperature of 80 °C owing to the higher tapped density and improved flowability of the powder, which result in high-quality powder bed formation. In addition, numerical simulations were conducted to estimate the effect of the powder quality on laser energy absorption and, thus, melt pool formation. The results reveal that enhanced powder characteristics result in an increased density and prevent lack of fusion while tuning the grain boundary characteristics and strengthening the crystallographic texture, which resulted in decreased cracking owing to less crack-sensitive grain boundaries and increased hardness of the as-built W components.

Sun S.H., Hagihara K., Ishimoto T., et al. Comparison of microstructure, crystallographic texture, and mechanical properties in Ti–15Mo–5Zr–3Al alloys fabricated via electron and laser beam powder bed fusion technologies. Additive Manufacturing, 47, 102329. https://doi.org/10.1016/j.addma.2021.102329., Depending on the application, establishing a strategy for selecting the type of powder bed fusion technology—from electron beam (EB-PBF) or laser powder bed fusion (L-PBF)—is important. In this study, we focused on the β-type Ti–15Mo–5Zr–3Al alloy (expected for hard-tissue implant applications) as a model material, and we examined the variations in the microstructure, crystallographic texture, and resultant mechanical properties of specimens fabricated by L-PBF and EB-PBF. Because the melting mode transforms from the conduction mode to the keyhole mode with an increase in the energy density in L-PBF, the relative density of the L-PBF-built specimen decreases at higher energy densities, unlike that of the EB-PBF-built specimen. Although both EB-PBF and L-PBF can obtain cubic crystallographic textures via bidirectional scanning with a 90° rotation in each layer, the formation mechanisms of the textures were found to be different. The texture in the build direction is mainly derived from the vertically grown columnar cells in EB-PBF, whereas it is derived from the vertically and horizontally grown columnar cells in L-PBF. Consequently, different textures were developed via bidirectional scanning without rotation in each layer: the and aligned textures along the build direction in L-PBF and EB-PBF, respectively. The L-PBF-built specimen exhibited considerably better ductility, but slightly lower strength than the EB-PBF-built specimen, under the conditions of the same crystallographic texture and relative density. We attributed this to the variation in the microstructures of the specimens; the formation of the α-phase was completely absent in the L-PBF-built specimen. The results demonstrate the importance of properly selecting the two technologies according to the material and its application.

The influence of crystallographic texture on the total amount of solute segregated at the grain boundaries (Xgb,tot) and consequently the weighted grain boundary energy (γw) of a nanocrystalline material is investigated. Toward this end, two different 3D nanostructures, one with random crystallographic texture and the other with {111} texture, were generated. The grain boundary misorientation distribution was obtained from both the 3D nanostructures and converted into an equivalent grain boundary energy distribution using the data from Olmstead et al. It was found that both Xgb,tot and γw are higher for the nanostructure bearing random texture vis-a-vis the {111} texture. This has implications in the development of thermally stable nanocrystalline materials. The effect of texture is also discussed through a case study on the Ni–W system by invoking the nanocrystalline stability criterion proposed by Kalidindi and Schuh.

A finite element microstructure model with permeability tensors that considers crystallographic texture and grain size based on magnetic domain theory has been developed for the evaluation of magnetic anisotropy in polycrystalline steels. The model has proved capable of capturing the crystallographic texture, the grain size and the vector induction effects on the effective permeability behaviours for typical textures in steels. The predicted magnetic properties as a function of the magnetic field direction enables a quantitative characterisation of the magnetic anisotropy. The predicted effective permeability maps can serve as a visual indication of the crystallographic texture from magnetic values. These features have been experimentally validated against a commercial grain oriented electrical steel featuring strong texture and magnetic anisotropy.

Aluminum foil undergoes severe plastic deformation and multiple heat treatments during processing, and the texture characteristics become very identifiable. In this research, textured AA8021 aluminum foil was obtained by adjusting the fabrication process. The anisotropic behavior of aluminum foil was studied by tensile testing. The surface morphology and texture evolution of the aluminum foil were studied before and after tensile testing by means of digital microscopy, optical profilometry and electron backscattered diffraction. The experimental results showed that compared with the samples tested at 0° and 90° to the rolling direction, the samples tested at 45° to the rolling direction exhibited lower yield strengths and flow stresses due to the “soft orientation” of most grains. Additionally, when the aluminum foil was tensile tested at 45° to the rolling direction, the shear bands on the surface of the aluminum foil were long, dense, bent and crossed. The rotation of cube grains caused the aluminum foil matrix to undergo significant geometric hardening, increasing the strain hardening index n. Additionally, the rolling texture improved the anti-thinning ability of the aluminum foil at 45° to the rolling direction, significantly increasing the ultimate strain reached in the 45° direction. These research results provide important theoretical guidance for improving the drawability of aluminum foil box-shaped parts by adjusting the microtexture under industrial conditions.

Zirconium remains the main structural material for thermal reactors due to the small capture cross section of thermal neutrons. In the period of stricter safety requirements for reactors with a simultaneous increase in operating parameters, predicting the behavior of the material in emergency situations has gained greater urgency. In this work, we measured the temperature dependence of the thermal expansion of samples cut from thick-walled tubes made of Zr-2.5% Nb alloy that were deformed and annealed in different modes. The analysis of the physical processes responsible for the shaping of the material is carried out. It was found that the anisotropic change in the linear dimensions of cubic samples both during heating and cooling is due to a change in the zirconium content in the β-phase, phase transformations α + β-Zr → α + β-Nb → β → α + β-Zr, as well as the preferred orientation of the grains of the α-phase, characterized by high anisotropy of linear expansion. It is shown that the expansion of the investigated samples upon heating in the α -phase is determined exclusively by the integral texture parameters of Kearns, and the coefficients of thermal linear expansion (TLEC) in different directions vary over a wide range from 3⋅10-6 to 12⋅10-6 K−1. During cooling at the stage of the reverse phase transformation of the β-phase into α, an increase in the size of the cubic samples in the tangential direction up to 2.3 % and a decrease in the radial direction to 1.3 % are noted, which is associated with the orientation of the α-phase grains formed during cooling in the β -matrix and anisotropy of the TLEC of the α -grains. It is shown that the orientation of the α-phase grains in the reverse β → α transformation is determined not only by the orientation of the basal axes in the initial material, but also by the spatial distribution of the prismatic axes relative to the external directions in the tube. Significant size fluctuations in different directions of the samples obtained using the technology of manufacturing channel tubes for CANDU reactors should lead to the development of significant macrostresses both during heating and cooling of the tube. The structural state of the samples deformed or annealed at 400–530 °C does not significantly affect the temperature dependence of the TLEC, but is manifested only in some of its features. In this case, completely recrystallized samples, i.e., with a recrystallization texture, in which the 2 - 0 > directions are oriented along the tube axis, are characterized by a significantly lower variation in dimensions in different directions in the temperature range 20–1200 °C.

Ishimoto T., Hagihara K., Hisamoto K., et al. Stability of crystallographic texture in laser powder bed fusion: Understanding the competition of crystal growth using a single crystalline seed. Additive Manufacturing, 43, 102004. https://doi.org/10.1016/j.addma.2021.102004., In metal additive manufacturing, crystallographic orientation control is a promising method for tailoring the functions of metallic parts. However, despite its importance in the fabrication of texture-controlled functional parts, the stability of the crystallographic texture is not widely discussed. Herein, the crystallographic texture stability under laser powder bed fusion was investigated. Two methodologies were employed. One is that a laser scanning strategy was alternately changed for a specific number of layers. The other is a “seeding” experiment in which single-crystalline substrates with controlled crystallographic orientations in the building (z-) direction and the xy-plane (perpendicular to the building direction) were used as the starting substrate. The transient zone width, where the crystallographic orientation was inherited from the layer beneath, was analyzed to evaluate the texture stability. The crystallographic direction of the seed within the xy-plane, rather than the building direction, determined the transient zone width, i.e., the texture stability. In particular, the texture in the newly deposited portion was stable when the laser scanning direction matched the orientation in the underneath layer, otherwise the crystal orientation switched rapidly, such that the orientation was parallel to the scanning direction. Interestingly, the crystallographic orientation along the building direction in the underneath layer hardly impacted the stability of the texture. Therefore, for the first time, it has been clarified that the orientation in the scanning direction, rather than the building direction, was preferentially stabilized, whereas the orientation in the other directions secondary stabilized.

The effect of crystallographic texture on the corrosion performance of the Ti6Al4V alloy with a typical bimodal microstructure has been studied on three orthogonal surfaces of the rectangular sample. The optical microscopy (OM) and scanning electron microscopy (SEM) observations revealed that the same microstructure is developed on three surfaces via heat treatment. The crystallographic planes, which are located in parallel to each surface, have been evaluated through macrotexture analysis. The electrochemical measurements showed that the RD-ND surface (i.e., surface normal to transverse direction), in which $$ \left\{ { 0 0 0 2} \right\} $$ and $$ \{ 11\bar{2}0\} $$ crystallographic planes are placed in parallel to the surface, has the lowest corrosion rate equal to 2.2 × 10−5 mm/year. In contrast, the corrosion rate of the TD-ND surface, which is normal to the rolling direction, with $$ \left\{ { 1 0\bar{1} 0} \right\} $$ planes in parallel to the surface is ~ 15 times greater than that of the RD-TD surface. Electrochemical impedance spectroscopy (EIS) results showed that the greater corrosion resistance of different surfaces is mainly dependent on the passive layer properties formed on each surface.

The effect of reversible hydrogen alloying on the structure, the hot plastic deformation resistance, and the crystallographic texture of a Ti–9.1 Al–2.2 Mo–1.6 Zr alloy (wt %) is studied. The dependences of the type and parameters of structure on the introduced hydrogen concentration and the vacuum annealing conditions are presented. A decrease in the yield strength of the alloy containing 0.15–0.6 wt % hydrogen by 140–210 MPa and a decrease in its flow stresses during plastic deformation are detected. The type and quantitative characteristics of the α-phase texture after hot isothermal upsetting and vacuum annealing of alloys with various hydrogen contents are determined.

A multilevel mathematical model is proposed for studying the technological processing of metals and alloys by severe plastic deformation. The model is based on crystal elasto-viscoplasticity and can describe the evolving structure as well as predict crystallographic texture formation. A geometrically nonlinear nonstationary boundary value problem of quasi-static elasto-viscoplastic deformation of macroscopic polycrystalline samples is formulated in rate form, including systems of equations describing physical mechanisms at various structural scale levels. A distinctive feature of the proposed formulation is that it takes into account variable contact conditions on the material surface specified for each moment of the loading process. As a basic constitutive model, a two-level model of a polycrystal is used in which the characteristics of a macroscopic representative volume are calculated by consistent statistical averaging over the values of similar quantities for the contained mesoscopic elements (crystallites). Within the approach used, information on crystallographic textures in different parts of the workpiece is provided in the form of samples of crystal lattice orientations. The associated output data of numerical calculations are reproduced in a reduced form using cluster analysis methods. The developed apparatus is applied to study the drawing of a solid copper cylinder.

A new concept named “rotating magnetocaloric effect (RMCE)” has been proposed and attracted more attention recently. Unlike the traditional MCE that is achieved by moving the magnetic refrigerant in and out of magnetic field, RMCE can be realized by rotating the anisotropic material within the static field, thus implying the possible higher efficiency and simpler device. However, most studies on RMCE are concentrated on single crystals, which are generally more expensive and difficult to prepare in comparison with polycrystals. Therefore, it is highly desirable to search polycrystalline materials with high RMCE. Here, the textured HoNiSi polycrystal is reported to show a giant RMCE, e.g., the rotating magnetic entropy change (−ΔSR) are 18.5 and 26.7 J/kg K and rotating adiabatic temperature change (ΔTR) are 7.0 and 13.4 K under 2 and 5 T, respectively. This giant RMCE over a wide temperature range especially under low field suggests textured HoNiSi as promising material for practical application of rotary magnetic refrigeration. Moreover, the large magnetic anisotropy of HoNiSi is explained by the single-ion magnetic anisotropy theory, and the coherent orientation of crystallographic texture and rare-earth ion moments leads to the large RMCE in the textured HoNiSi polycrystal. This work reveals that the strongly coherent orientation of crystallographic texture and rare-earth ion moments is a key to realize large RMCE in polycrystalline materials.

Tension-compression fatigue tests were conducted on forged (F-950) and rolled (R-950) Ti-6Al-4V alloys. The role of basal texture, produced by forging, was compared with prismatic texture, produced by rolling, on microstructurally short fatigue crack growth initiation and growth resistance. The fatigue life of R-950 alloy proved to be higher than that of F-950 alloy. Major differences in fatigue crack growth rate were detected in the short fatigue crack region at crack lengths of below 100 µm (F-950 alloy showing low resistance). To quantify the effect of texture alone, the opening/closure behaviour of a microstructurally small crack was analysed from the data obtained by combining an automatic in situ observation system with a digital image correlation technique. This analysis showed the crack opening stress of both alloys to be close to identical in the short fatigue crack growth region, nullifying the effect of crack closure. To study the effect of texture, cross-sectional electron backscatter diffraction analysis was performed at crack initiation sites. The results revealed that in F-950 alloy, short fatigue crack growth proceeded along basal planes that had similarly-oriented grains, whereas in R-950 alloy, short fatigue crack growth did not follow prismatic planes: the orientation varied.

The strain-induced martensite transformation is of great importance in the strain hardening process of ferrite based low-density steel. Based on the microstructure analysis, the texture evolution and martensite transformation behavior in the strain hardening process were studied. The results show that martensite transformation accompanied by TWIP effect and high density dislocations maintains the continuous hardening stage. As the strain increases, the texture of retained austenite evolves towards the F orientation {111} , which is not conducive to martensite transformation. After the strain of 5%, the number of austenite grains with high Schmid factor orientations is gradually increased, and then significantly reduced when the strain is over 10 % due to the occurrence of martensitic transformation, which results in a high martensitic transformation rate. However, the unfavorable orientation and the reduced grain size of austenite slow down the martensite transformation at the final hardening stage. Moreover, because of the coordination deformation of austenite grains, strain preferentially spreads between adjacent austenite grains. Consequently, the martensite transformation rate in strain hardening process is dependent on the orientation and grain size evolution of austenite, leading to a differential contribution to each strain hardening stage.

The range in which the α-phase texture in hot-rolled sheets made of VT18U, VT41, and VT25U titanium alloys changes is found. Yield strength contours are calculated using the integral α-phase texture parameters. The yield strength anisotropy is shown to decrease with increasing β-phase content to 25 vol %, but it continues to depend on the texture of the α phase.

Mechanically induced migration of grain boundaries and triple junctions not only determines the size and shape of nanostructures created by severe plastic deformation, it substantially affects their mechanical properties as well. Grain growth during deformation of nanostructures has been widely observed. As the nanostructures processed by severe plastic deformation are a consequence of a dynamic equilibrium between refinement and local mechanically induced coarsening, it is widely accepted that such nanostructures would remain stable upon further loading. However, pronounced grain coarsening can be observed when pure UFG copper prepared by high pressure torsion (HPT) is additionally cold rolled. The coarsening continues up to rolling strains, e = 1, i.e. until favourable grain orientations for rolling are developed. For larger strains subsequent refinement to minimum boundary spacing identical to the HPT microstructure is observed. Interestingly, less grain growth is observed for two other sample orientations of the HPT microstructure which are rolled along different directions with respect to the sample coordinate frame. Crystallographic texture of these samples were favourable with respect to the new strain path, highlighting its role for mechanically induced growth and suggesting a distinct influence of grain orientation on the mechanically induced coarsening process.

This paper investigates the effect of crystallographic texture on the corrosion product morphology and corrosion behavior of AZ31 magnesium alloy after immersion in simulated body fluid for 3 days. The microstructure and macrotexture analyses are performed through optical microscopy and x-ray diffraction methods, respectively. The polarization test evaluated the corrosion, and the FESEM electron microscope equipped with EDS was used to investigate the morphology of the corrosion products. According to the results, the morphology of calcium phosphate deposit as a corrosion product at the surface with basal texture was a porous cauliflower shape. In contrast, the calcium phosphate deposit at the surface of the nonbasal texture was uniform and nanoworm-like. The corrosion rate at the basal texture surface was higher than the nonbasal one, which is attributed to the difference in the morphology of calcium phosphate film.

Porous ceramic diesel particulate filters (DPFs) are extruded products that possess macroscopic anisotropic mechanical and thermal properties. This anisotropy is caused by both morphological features (mostly the orientation of porosity) and crystallographic texture. We systematically studied those two aspects in two aluminum titanate ceramic materials of different porosity using mercury porosimetry, gas adsorption, electron microscopy, X-ray diffraction, and X-ray refraction radiography. We found that a lower porosity content implies a larger isotropy of both the crystal texture and the porosity orientation. We also found that, analogous to cordierite, crystallites do align with their axis of negative thermal expansion along the extrusion direction. However, unlike what found for cordierite, the aluminium titanate crystallite form is such that a more pronounced (0 0 2) texture along the extrusion direction implies porosity aligned perpendicular to it.

Pure Mo bulk samples were fabricated by selective laser melting (SLM) with various process parameters. Two microstructural characteristics, namely, defect and the crystallographic texture, were investigated in detail. The laser power, scan speed, and layer thickness were widely varied, and the effects of each parameter on the microstructure were evaluated individually. Lack of fusion pore and spherical keyhole pore were found. The porosity decreased with an increase in the volumetric energy density (VED). The crystallographic texture characteristics along the build direction were investigated using electron backscatter diffraction analysis. It was confirmed that, similar to other materials, pure Mo tends to form a crystallographic texture. A strong fiber texture was observed at a high laser power (350 W) and low scan speed (400 mm/s). However, this fiber texture changed completely to a fiber texture when the scan speed was increased to 800 mm/s. Scan speed had a significant effect on the resulting texture characteristics directly. Other process parameters, laser power, layer thickness and hatch distance had an effect indirectly by changing the VED value on the texture.

The pure copper wires were wiredrawn at cryogenic and room temperatures. After deformation they presented important and significant differences in their crystallographic textures and microstructures. Therefore, this study aimed to investigate the evolution of crystallographic texture of pure copper drawn at temperatures of 295 K and 77 K and correlated them to the deformation micromechanisms. For this, the X ray diffraction (XRD) and electron backscattered diffraction (EBSD) techniques were used. The results showed that, after the deformation, the samples drawn at both temperatures showed Copper {112} , X {110} and Brass {110} components as the most intense. In samples drawn at cryogenic temperature there was also observed the appearance of a R{124} component, typical of recrystallization and the presence of the  fiber {111} , typical of deformation twin. Keywords: copper drawn, 77K drawing, 295K drawing, microtexture, crystallographic texture.

This paper examines the distribution of the tangential and normal components of the magnetic leakage fields in pole-magnetized sheet materials, such as cold-worked structural steels St3, 09G2S, and 08G2B, as well as electrical steel with different grain structure and coarse-grained magnetically soft alloy Alfer, which have different types of texture induced by rolling and uniaxial tension. It has been found that even minor changes in the preferential orientation of easy magnetization axes 〈100〉 strongly affect the distribution of the tangential Нτ and normalHn components of magnetic leakage fields. For all studied materials, the magnitude ofНτ significantly exceeds that ofHn. However, in most cases, the componentНn exhibits a larger anisotropy thanНτ. Cold plastic working by rolling and uniaxial tension changes the texture state of the studied structural steels with the formation of multicomponent textures, which causes changes in the angular dependences of the parametersНτ and Hn. This fact indicates that the onset of plastic flow in a ferromagnetic material can be detected by changes in the form of circle diagrams of the leakage field components. The circle diagrams of the parametersНτ and Hn of deformed structural steels have the form of figure-eight patterns that are approximately perpendicular to each other. The position of the maxima of Нτ andHn on these diagrams corresponds to the position of the projections of the easy magnetization axes closest to the rolling plane, i.e., the directions along which iron and its alloys have the lowest strength. Therefore, it may be effective to estimate the anisotropy of strength properties of steel products with different texture states by the anisotropy of their magnetic parameters. More reliable results of magnetic texture analysis can be obtained by constructing full circle diagrams of the magnetic leakage field parameters.

The contractile strain ratio (CSR) is an important property and a quality control factor of cold-worked and stress-relieved Ti–3Al–2.5V tubing. In this work, the CSR values of three thin-walled Ti–3Al–2.5V tubing samples were obtained by uniaxial tensile tests, and the crystallographic textures of the tubing samples were characterized by orientation distribution functions (ODFs) which were determined on the basis of a series of pole figures obtained by X-ray diffraction. A quantitative method is proposed for exploring the correlation between the CSR values and the ODF data of the tubing samples, including the following steps: Firstly, taking advantage of the ODF data, the volume fraction (V%) of crystallites that lie within a certain range of Euler angles (φ1, Φ, φ2) can be calculated, and the calculation is performed on each set of Euler angles (φ1, Φ, φ2). Secondly, each V% is resolved into an effective fraction in the orientation of the ideal radial texture {0002}〈10\overline 10〉 corresponding to the Euler angles of (0, 0, 0), and the equivalent radial texture (ERT) is obtained as the sum of all such effective fractions. Thirdly, similarly to the previous step, the equivalent tangential texture (ETT) is calculated. The CSR will be related to the ratio of the ERT to the ETT, named the equivalent texture ratio (ETR). The CSR values of the tubing samples are 1.38, 1.96 and 2.19 and their ETR values are 1.33, 1.72 and 1.87, respectively. In particular, the CSR and the ETR of the tubing with a random distribution of the basal poles in the radial–tangential plane are both unity. It is found from the above data that the CSR increases approximately linearly with the ETR. Since the three-dimensional orientations of crystallites and the orientation distributions throughout the Euler space are taken into account in the calculations of the ETR, the proposed method can be used for predicting and explaining the mechanical anisotropy of Ti–3Al–2.5V tubing more accurately.

The paper is devoted to the study of the mechanical, microstructural, and bio-corrosive behavior of low-alloyed Zn–Mg biodegradable surgical wires for bone reconstructions. Three biodegradable alloys with different magnesium content have been studied, their production technology has been developed and the product properties have been determined. The technology includes casting, extrusion, hot and cold drawing of the wire, and the product surface finishing. The paper shows the most important stages of the process (i.e., extrusion and drawing) in detail. The technological parameters have been selected based on the results of the computer modeling. The flow stress–strain curves of extruded materials have been obtained at various strain rates and temperatures. Two drawing technologies have been compared. The first one is the room temperature conventional wire drawing. In the second one, the first few passes have been made at an elevated temperature and the rest at room temperature. This allowed avoiding the breaking of the wire during the first passes (a typical issue of the conventional technology for these alloys) and increasing the ductility of the final product. Mechanical properties, bio-corrosion, and crystallographic texture of the material were determined at different stages of the processing. A simultaneous increase in the wire strength, the number of repeated bending until the rupture of the wire, and in the bio-corrosion rate due to drawing has been registered. This phenomenon coincided with a change in the crystallographic texture. It has been shown that the product tensile strength of about 250–300 MPa can be reduced by about 30% due to surgical knots tied on it.

Cold pilgering has been considered as the preferred rolling fabrication technology for difficult-to-deform tubular materials such as high-strength titanium alloy tubes. However, the tooling geometry may induce complex deformation and significantly influence crystallographic texture which is closely related to the dimension assuring and properties tailoring of tube products. In this study, taking high-strength Ti-3Al-2.5V tubes as the case material, the tooling design–related spatial deformation behaviors and crystallographic texture evolution of tube in cold pilgering are focused. A macro-meso scaled computation platform is established by combining the three-dimensional finite element (3D-FE) model with the viscoplastic self-consistent (VPSC) crystal plasticity model to predict both the inhomogeneous macrodeformation and microtexture evolution in cold pilgering. Two basic tooling parameters in pilgering, viz., E1 representing exponent of roller groove curve and mandrel curve and E2 representing exponent of groove clearance, are chosen as the design variables. The cold pilgering under different tooling parameters are simulated and analyzed. The results show that (1) The rolling force decreases with the increase of E1 , while the effect of E2 on the rolling force is not significant, and smaller E1 and larger E2 have advantage for preventing surface defects of the tube product; (2) The E1 of 2.8 and E2 of 2.0 are more conducive to the wall thinning–dominated deformation of tube; (3) Taking the contractile strain ratio (CSR) as an indicator for characterizing crystallographic texture–related mechanical properties, the appropriate values of E1 and E2 for desirable radial texture of tube product are obtained.

We examined the effect of the crystallographic texture on the thermo-elastic strain of polycrystalline Fe–Pd magnetic shape memory alloy (MSMA) thin films that were sputter-deposited in the presence of a magnetic field. The thermo-elastic strain of an Fe–27.8 at% Pd film sputtered in the presence of a magnetic field was more than six times larger than that of a film deposited without magnetic field. We attribute the increased thermo-elastic strain to a shift in the crystallographic texture; from a 〈111〉 fiber texture for films deposited without magnetic field to a {113}〈411〉 texture for films deposited with magnetic field.

This paper presents the main results from an investigation into the effect of initial microstructure on high cycle fatigue behavior of Inconel 718 superalloy. To create a variety of initial microstructures, the material was deposited at a 45° (diagonal) and a 90° (horizontal) angle with respect to the loading direction using direct metal laser melting (DMLM). In addition, a group of samples underwent hot isostatic pressing (HIP). Finally, a set of wrought Inconel 718 specimens was prepared. The samples underwent the same heat treatment per AMS 5663 after machining. The microstructure in the samples was characterized and found to vary in terms of grain structure, crystallographic texture, content of annealing twin boundaries, precipitates, and porosity. Stress controlled rotary bending fatigue tests were carried out to an endurance limit of 107 cycles at room temperature and at 500 °C with stress amplitudes ranging from 200 MPa to 1200 MPa. It was found that for low stress amplitudes, the fatigue strength is higher at elevated temperature than at room temperature for all the studied samples. For higher stress amplitudes, the materials showed a higher fatigue strength at room temperature than at elevated temperature. At room temperature, the wrought material was found to exhibit superior fatigue performance over the DMLM diagonal and DMLM horizontal materials. In contrast, at 500 °C, the wrought and DMLM materials behaved similarly, while the HIPed material performed notably worse than all other materials. The observed behaviors are rationalized in terms of the initial microstructure of the samples. Since crystallographic texture is weak in every material, effects of gran size, porosity, precipitates, and grain boundaries are discussed as the main competing microstructural features influencing the fatigue performances.

This paper presents some results of the influence of severe plastic deformation on the microstructure evolution, grain refinement aspect, and mechanical properties of ultra-low carbon steel. Ti-stabilized experimental IF steel was deformed at a room temperature with unconventional SPD process—dual rolls equal channel extrusion (DRECE). Mechanical properties and structure of ferritic steel in initial state and after selected steps of deformation were investigated. The mechanical properties were determined by static tensile tests carried out at a room temperature and microhardness research. The structural investigations involved using scanning transmission electron microscopy observations, electron back scattered diffraction and measurements of the crystallographic texture. The DRECE process affects the evolution of the structure. The microstructural investigations revealed that the processed strips exhibited a dislocation cell and grain structures with mostly low angle grain boundaries. The electron backscattering diffraction (EBSD) examination showed that the processed microstructure is homogeneous along the strips thickness. The mechanical properties of the DRECE-processed IF steel strips increased with an increase the number of passes.

The biocompatibility of orthopedic implants is closely related to their elastic modulus and surface properties. The objective of this study was to determine the effects of cold rolling, recrystallization and laser surface melting (LSM) on the microstructure and mechanical properties of a biphase (α″+β) Ti−30Nb−4Sn alloy. X-ray diffraction (XRD) texture analysis of the cold-rolled substrate revealed the [302]α″//ND texture component, while analysis of the recrystallized substrate showed the [302]α″//ND and [110]α″//ND components. The β-phase texture could not be directly measured by XRD, but the presence of the [111]β//ND texture component was successfully predicted by considering the orientation relationship between the α″ and β phases. Nanoindentation measurements showed that the elastic modulus of the cold-rolled substrate (63 GPa) was lower than that of the recrystallized substrate (74 GPa). Based on the available literature and the results presented here, it is suggested that this difference is caused by the introduction of crystal defects during cold deformation. The combined nanoindentation/EBSD analysis showed that the nanoindentation results are not affected by crystal orientation. LSM of the deformed alloy produced changes in hardness, elastic modulus and crystallographic texture similar to those produced by recrystallization heat treatment, creating a stiffness gradient between surface and substrate.

Mechanisms underlying the evolution of texture and microstructure during selective laser melting (SLM) and their combined effects on the mechanical response of 316L stainless steel are presented. Long columnar grains with a fiber texture || build direction (BD) evolved in the SLM printed material. Fiber texture was stronger in the horizontal build compared to the vertical build. Use of bidirectional scanning strategy enforced epitaxial growth of grains across melt pools present within a single printed layer. || BD texture evolved as a consequence of maintaining the balance between epitaxy and growth of [100] along maximum thermal gradient. High dislocation density and not grain size effect of the ultra-fine cellular structure, imparted high strength to 316L. Lower average Schmid factor and smaller effective grain size in the horizontal build by virtues of crystallographic and morphological textures, respectively, imparted higher yield strength than the vertical build. The horizontal build demonstrated higher strain hardening rate in the early stages of deformation compared to the vertical build due to higher crystallographic texture dependent twinning. However, the higher rate of dislocation annihilation led to a continuous decline in the strain hardening rate of the horizontal build. In contrast, a stable strain hardening rate was maintained in the vertical build, which led to higher ductility than the horizontal build. In summary, the roles of non-equilibrium microstructure and texture (crystallographic and morphological) in regulating mechanical properties elucidated here, can be utilized in designing additively manufactured structural components of 316L stainless steel.

Titanium and its alloys are the most suitable metallic materials available for the fabrication of medical implants. Their biocompatibility can be improved by the growth of TiO2 nanotubes on their surface by a simple anodization process. This work involved an investigation into the anodization behavior of Ti–35Nb–7Zr–5Ta (TNZT) alloy, focusing on the effect of processing conditions (anodization time and type of electrolyte), previous strain hardening, and crystallographic texture of the substrate. Studies about the growth of TiO2 nanotubes on β-type titanium alloys, as the TNZT alloy, are rare in the literature. The TNZT alloy proved to be an excellent substrate for the growth of TiO2 nanotubes, resulting in threefold longer nanotubes than those obtained on a commercially pure (CP) Ti substrate. Moreover, TiO2 nanowires grew after 6 h of anodization in an organic electrolyte, which could not be achieved using the CP-Ti substrate. Samples with different crystallographic textures displayed similar nanotube morphology and only slight differences in grain length, indicating that grain orientation played only a minor role in the growth kinetics. Lastly, the crystallization of nanotubes at 450 °C did not alter their morphology, but caused complete detachment of the TiO2 nanotubes at 700 °C.

Pronounced crystallographic texture, characteristic for the parts manufactured by selective laser melting, is eliminated upon addition of TiB2 microparticles to Al-12Si powder. Due to the wetting of TiB2 ceramic by Al-12Si melt and a high inoculation efficiency, a homogeneous microstructure consisting of fine equiaxed grains with random crystallographic orientation is formed by SLM processing of the Al-12Si/TiB2 powder mixture. The Al-12Si/TiB2 samples exhibit enhanced yield strength and microhardness, compared to the TiB2-free Al-12Si samples produced at the same SLM conditions.

A mathematical model is developed to study the influence of the crystallographic texture of aluminum sheets on the fracture toughness of glass laminate aluminum reinforced epoxy (GLARE). The most favorable ideal crystallographic orientations of the aluminum sheets and the directions of arrangement of fibers in glass-reinforced plastic that increase the fracture toughness of GLARE by more than 15% are determined.

This work presents a model capable of describing the influence of the crystallographic texture and microstructure produced by Voronoi tessellation on the initial stage of pitting corrosion in API 5L steels. The proposed model takes into account several physical parameters of the material such as crystallographic orientation, gran size, grain boundary, number of inclusions, surface energy, and the Gibbs free energy change. The number of corrosion pits and their distribution associated with the initiation of pitting corrosion were determined using both Monte Carlo simulation and corrosion test. The good agreement between simulation results and the experimental observations verified the validity of the proposed model. The results showed that the pits initiation depends strongly on the change of surface energy due to the formation of new phases and the character of grain boundary and its distribution. The behaviour of nucleated pits is completely random, while their subsequent growth from a nucleation site has a strong influence from the crystallographic grains orientation.

The Charpy impact toughness (CVN) properties of a Nb + V microalloyed X70 steel of YS∼ 540 MPa was studied at various angles with respect to the rolling direction. The microstructure of the steel was characterised using light optical microscope, scanning electron microscope (SEM) and the transformation textures were evaluated from the orientation distribution function (ODF) measured from the electron back-scattered diffraction (EBSD) experiments. The skeleton lines, showing intensity distribution, f(g), of the fcc-to-bcc transformation texture, namely the α-fiber ( ∥ RD), the γ-fiber ( ∥ ND) and e-fiber ( ∥ TD) are considered to explain the observed behavior in mechanical properties. The major components like, {112} , {113} , {332} , {111} and {111} , their relative intensity distribution, are found to act in a complex manner towards controlling the mechanical behavior during impact and tensile testing. It has been observed that, the type and extent of delamination normally observed in broken Charpy specimens, which is commonly believed to be more dependent on the banding of 2nd phases in the microstructure, is found to be controlled by crystallographic texture, mostly clustering of {100} grains in the primary and secondary cleavage planes.

A directionally solidified Ag-Cu eutectic alloy was deformed by rolling to understand the role of heterophase interfaces on the deformation behavior of ultrafine and nanocrystalline face-centred cubic metals. During rolling, the initial 〈220〉 fibre texture was gradually shifted to a Brass type texture for both Ag and Cu phases. More interestingly, a similar path of texture evolution was observed for both the phases at all strain levels. The in-depth transmission electron microscopy analysis revealed that the Ag lamellae deformed primarily by twinning, while the Cu lamellae deformed by twinning and dislocation slip. Furthermore, the special cube-on-cube and twin heterophase interfaces facilitated co-deformation and co-rotation of the adjacent Ag and Cu lamella due to a strong latent hardening effect, which stimulated a similar texture evolution for both phases.

Texture formation processes at all technological stages of tube manufacture were considered. It has been established that at the stage of hot deformation and manufacture of TREX tubes, tangential and radial textures are formed, a large share of tangential component of the texture. Influence of main factors of the technological process on formation of texture and properties was established. Conditions for formation of a maximum amount of radial texture in tubes which ensure improvement of service properties of tubes were determined. To create maximum amount of radial texture in tubes, total reduction rate in passes and the wall to diameter reduction ratio (factor Q) are important. The reduction rate should be increased, especially in the last passes, to 75…85%. Heat treatment (stress relief annealing) practically does not change the tube texture.

In the present work, the tribological performance of solution treated Ti–27.96Nb–11.97Ta–5.02Zr (wt%) alloy has been assessed after 1000 m sliding at the applied load of 2N, 5N, 20N and 50N and sliding speed of 300 mm/s against Ti–6Al–4V ELI. The near-surface micro-texture evolution induced by frictional force has been investigated in detail using SEM-EBSD. According to the results, TNTZ alloy shows better tribological performance compared to Ti–6Al–4V ELI in all the applied loads. The signs of oxidation and adhesion wear were clearly observed on all the worn surfaces of the worn alloys. Low wear weight loss of TNTZ alloy at lower applied loads is due to the continuous substructure development as well as the formation of γ-fiber alignment texture along the sliding direction in absence of texture in the highly refined β grains. The results showed that the transition from γ-fiber texture to cube texture takes place with the increase of applied load to 50N and networked leading to brittle fracture and third body abrasive wear particle generation. These phenomena have a high influence on the wear rate of TNTZ alloy when the applied load increases. Neither the grain elongation nor the shear bands were formed in the subsurface of worn deformed specimens.

The influences of Sr on the microstructure, texture and mechanical properties including flow and anisotropy behavior of AZ31 alloys are investigated. Slabs containing no, 0.4 and 0.8 wt% of strontium were cast and subjected to hot rolling. Results indicate that Sr reduces the basal texture intensity (23% in the AZ31+0.8Sr alloy) and homogenizes the distribution of strain in uniaxial tension. Furthermore, Sr increases both the strength coefficient and the strain hardening exponent in all directions. In the transverse direction, enhancements are more significant. Moreover, Sr enhances the combination of tensile strength and total elongation; i.e., toughness, whether tests are performed parallel to the rolling, diagonal or transverse directions, to significant extents. Keywords: AZ31, Hot rolling, Mechanical properties, Microstructure, Strontium, Texture

This paper aims at understanding the texture evolution in extruded oxide dispersion strengthened 18Cr ferritic steel during high-temperature uniaxial compression testing at 1,423 K at a strain rate of 0.01/s based on extensive electron back scatter diffraction characterization. The α-fiber texture is observed along the extrusion direction (ED) in the initial microstructure. The flow curves generated during uniaxial compression test are used to determine the associated hardening parameters. In addition, the degree of texture evolution after deformation along the ED and the transverse direction (TD) with respect to the initial condition has been predicted using VPSC-5 constitutive model. The prediction shows that the deformation along the ED produces a dominant γ-fiber texture in contrast to the TD. This is in agreement with the experimental results where γ-fiber texture is observed, due to enhanced dynamic recrystallization at high-temperature deformation.

The mechanical anisotropy of FCC aluminium alloy is influenced by the polycrystalline orientations transformed by cold rolling. The relationship between mechanical anisotropy and evolution of crystallographic textures was established using the crystal plasticity finite element method (CPFEM) based on measured polycrystalline orientation density functions (ODFs) and used to determine the parameters of a phenomenological convex anisotropic yield function which are solved with an implicit finite element (FE) stress integration code. A multi-scale modelling system is generated by combining CPFEM and the phenomenological yield function enabling accurate simulations of forming operations without the need for conventional physical mechanical testing of the material.

Variation of the texture and grain state of refractory nickel alloy ZhS6K-VI synthesized by the method of selective laser melting is studied as a function of the sintering mode, the type of hatching and heat treatment. Two types of hatching are employed, i.e., diagonal-island and checkerboard ones. The texture is studied. Orientation maps of fragments are plotted with the help of the EBSD method. Regular features of structure formation depending on the synthesis mode are determined.