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Magnesium-Zinc-Zirconium (Mg-Zn-Zr) alloys have caught considerable attention in medical applications where biodegradability is critical. The combination of their good biocompatibility, improved strength, and low cytotoxicity makes them great candidates for medical implants. This research investigation is focused on providing further insight into the effects of equal channel angular processing (ECAP) on the corrosion behavior, microstructure evolution, and mechanical properties of a biodegradable ZK30 alloy. Billets of Mg-3Zn-0.6 Zr (ZK30) alloy were processed through ECAP up to 4 passes of route Bc (rotating the billets 90° in the same direction between the subsequent passes) at 250 °C. Electron back-scatter diffraction (EBSD) was utilized to investigate the microstructural evolution as well as the crystallographic texture. Several electrochemical measurements were carried out on both a simulated body fluid and a 3.5% sodium chloride (NaCl) solution. Mechanical properties such as Vicker's hardness and tensile properties were also assessed. The as-annealed (AA) microstructure was dominated by equiaxed coarse recrystallized grains with an average grain size of 26.69 µm. After processing, a geometric grain subdivision took place due to the severe plastic deformation. Processed samples were characterized by grain refinement and high density of substructures. The 4-passes sample experienced a reduction in the grain size by 92.8% compared with its AA counterpart. The fraction of high-angle grain boundaries increased significantly after 4-passes compared to the 1-pass processed sample. With regards to the crystallographic texture, the AA condition had its {0001} basal planes mostly oriented parallel to the transversal direction. On the other hand, ECAP processing resulted in crystallographic texture changes, such as the shifting of the ZK30 shear plane to be aligned at 45° relative to the extrusion direction (ED). Furthermore, the maximum texture intensity was reduced from 14 times random (AA billets) to 8 times random after ECAP processing through 4-passes. The corrosion rate of the 4-passes sample was tremendously reduced by 99% and 45.25% compared with its AA counterpart in the simulated body fluid and the NaCl solution, respectively. The pitting corrosion resistance of ZK30 showed notable improvements in the simulated body fluid by 471.66% and 352% during processing through 1-pass and 4-passes, respectively, compared with the 3.5% NaCl findings. Finally, significant improvements in the tensile strength, hardness, and ductility were also achieved. [ABSTRACT FROM AUTHOR]

To enhance the formability of magnesium alloys, inhibition of basal texture development by the particle-stimulated nucleation (PSN) effect has attracted significant interest. However, its contribution to texture development is not easily observed due to the separation of texture from the conventional deformation behavior. This study aims to separate the Ca texture from the deformation behavior of AZX611 alloy and quantify it using scanning electron microscopy with electron backscatter diffraction (SEM-EBSD). Since Ca in the AZ61 magnesium alloy precipitated as Al2Ca, the hot-rolled magnesium alloys AZ31, AZ61, and AZX611 were used. High temperature compression was conducted at 723 K, the strain rate 0.05/s and 0.005/s and the true strain up to −1.0. Dynamic recrystallization was observed in each specimen and the Ca-free alloys showed dislocation glide at high strain rates and solute drag at low strain rates. When the dislocation glide dominated, basal texture was strengthened. In contrast, solute drag caused non-basal texture development. Precipitation hardening caused AZ61 to have higher flow stress than those of the Ca-free alloys by the PSN effect; its texture was observed separately because the PSN grain growth around the precipitation and orientation was specific, similar to the one developed at the solute atom drag. [ABSTRACT FROM AUTHOR]

Crystallographic texturing enables the design of piezoelectric polycrystals that outperform traditional random polycrystals by exhibiting outstanding piezoelectric properties. In this work, phase-field modeling and computer simulation were employed to study the effect of crystallographic texture on the piezoelectric properties of ferroelectric polycrystals at the domain level. Domain evolutions for single crystal, random polycrystal, and textured polycrystal are systematically simulated. The simulations reveal that the [001]-textured polycrystal can fully exploit the intrinsic anisotropic properties of piezoelectric materials by exhibiting a piezoelectric coefficient that is as large as that of single crystal while being much larger than that of random polycrystal. To better understand the mechanism of piezoelectricity enhancement by crystallographic texturing, a theoretical analysis based on Landau theory is provided. In comparison with random polycrystal, the textured polycrystal manifests a flatter energy landscape and thus possesses a higher piezoelectric coefficient. [ABSTRACT FROM AUTHOR]

Magnesium alloys such as AZ91 have received much attention due to their attractive properties, including biocompatibility and lightness. Although magnesium is a potential candidate for implant application, due to its rapid degradation in the physiological environment, there are still some challenges to using it as biocompatible implants. In this regard, various techniques such as microstructure modification and coating are utilized to moderate the degradation rate of magnesium alloys. Therefore, efforts are being made to conduct more extensive research to produce magnesium implants with acceptable corrosion resistance. In this literature review, an overview of the history of research on the corrosion behavior, biodegradability, microstructure deformation mechanisms, crystallographic texture in magnesium alloys with a focus on AZ91 Mg alloy, is provided. In addition, the necessity of improving the properties of AZ91 Mg alloy by the two methods of improving microstructure and coating, and existing innovations in these methods are investigated. [ABSTRACT FROM AUTHOR]

Additive manufacturing, known as “3D printing”, is a set of manufacturing technologies that can build parts with complex geometries in a process by adding layers of powder material. The laser powder bed fusion (L-PBF) process is characterized by selectively melting layers of particulate material at a micrometer scale in repetitive patterns. This technology is expected to improve Young's modulus of metallic biomaterials, by controlling the microstructure and crystallographic texture– influenced by the laser power and scanning speed parameters which promote an oriented heat extraction. Implant materials should have low Young's modulus, to avoid a large mismatch with that of the bones. This work investigates the role of the laser power and scanning speed on microstructure and crystallographic texture formation of the Nb–48Ti alloy, fabricated by laser powder bed fusion process, using pre-alloyed plasma atomized powder. The microstructure was characterized by optical microscopy (OM), scanning electron microscopy (SEM), backscattered electron diffraction technique (EBSD) for crystallographic texture, and Young's modulus was obtained indirectly via EBSD data. The microstructure showed a cellular dendritic solidification morphology formed by epitaxy at the edge of the melt pools. Texture results indicated that higher values of power and scanning speed favored the increasing of a near-cube-on-face texture and a reduction in Young's modulus.

Crystallographic texturing enables the design of piezoelectric polycrystals that outperform traditional random polycrystals by exhibiting outstanding piezoelectric properties. In this work, phase-field modeling and computer simulation were employed to study the effect of crystallographic texture on the piezoelectric properties of ferroelectric polycrystals at the domain level. Domain evolutions for single crystal, random polycrystal, and textured polycrystal are systematically simulated. The simulations reveal that the [001]-textured polycrystal can fully exploit the intrinsic anisotropic properties of piezoelectric materials by exhibiting a piezoelectric coefficient that is as large as that of single crystal while being much larger than that of random polycrystal. To better understand the mechanism of piezoelectricity enhancement by crystallographic texturing, a theoretical analysis based on Landau theory is provided. In comparison with random polycrystal, the textured polycrystal manifests a flatter energy landscape and thus possesses a higher piezoelectric coefficient.

Duplex stainless steels can be used for applications in the nuclear industry endorsing its choice as an external shield for Type B packages. The microstructure, crystallographic texture, and the strain hardening behavior of UNS S32304 duplex stainless steel was investigated in hot tensile tests by Electron Backscattering Diffraction technique. Interrupted hot tensile tests with strain rates ε˙ = 10−2 s−1 and ε˙ = 10−1 s−1 were carried out at 700 °C using a Thermomechanical Physical simulator. The α parameter of gamma distribution was associated for the first time with strain in ferrite and austenite phases through the Grain Orientation Spread parameter (GOS). The ferrite phase did not show the dynamic equilibrium between the stored energy and recovery rates. The average GOS in the ferrite phase was larger for ε˙ = 10−1 s−1 due to a smaller time available for dislocation annihilation and rearrangement in dynamic recovery. The grain rotation sequence → - → was found in ferrite phase. In the austenite phase, the dynamic recrystallization was not observed and the and fiber textures parallel to the tensile direction were strengthened. The austenite → ferrite phase transformation occurred during the hot tensile tests and showed the Kurdjumov-Sachs orientation relationship. The modified Crussard-Jaoul analysis showed six-strain hardening stages which were associated with the average GOS and austenite → ferrite phase transformation.

The mechanisms that govern a previously unexplained hardening effect of a single phase Cu-30wt%Zn α -brass after heating have been investigated. After cold-work, the alloy possesses an increased yield strength and hardening rate only when heat treated to temperatures close to 220 °C, and is otherwise softer. Crystallographic texture and microstructure, explored using electron backscatter diffraction (EBSD), describe the deformation heterogeneity including twin development, as a function of the heat treatment conditions. When heated, an increased area fraction of deformation twins is observed, with dimensions reaching a critical size that maximises the resistance to dislocation slip in the parent grains. The effect is shown to dominate over other alloy characteristics including short range order, giving serrated yielding during tensile testing which is mostly eliminated after heating. In-situ X-ray diffraction during tensile testing corroborates these findings; dislocation-related line broadening and lattice strain development between as-worked and heated α -brass is directly related to the interaction between the dislocations and the population of deformation twins. The experiments unambiguously disprove that other thermally-induced microstructure features contribute to thermal hardening. Specifically, the presence of recrystallised grains or second phases do not play a role. As these heat treatments match annealing conditions subjected to α -brass during deformation-related manufacturing processes, the results here are considered critical to understand, predict and exploit, where appropriate, any beneficial process-induced structural behaviour. [Display omitted] [ABSTRACT FROM AUTHOR]

Microstructural development, strengthening mechanisms, and mechanical properties of the newly developed Mg–5Sb- x SiCp (x = 0, 1, 3, and 5) composites were studied in both as-cast and extruded states. The microstructures of composites were composed of α-Mg, in-situ Mg 3 Sb 2 , and SiCp phases. The cooling curves display that Mg 3 Sb 2 intermetallics form as the primary phase. During solidification, the SiC p acts as heterogeneous sites for both α-Mg and intermetallics formation. The increase in SiCp content (from 0 % to 5 %) modified the as-cast grain size from 827 μm to 411 μm with the improvement of yield strength (YS) (74–97 MPa). Also, the SiC addition to as-cast facilitates the formation of a randomized texture and a significant reduction in intensity from 13.121 mrd to 6.301 mrd for SiC-Free and 5 wt% added MMCs, respectively. Grain refining and recrystallization are characterized by electron backscatter diffraction (EBSD) analysis. Grain refinement via SiCp and hot extrusion leads to substantial structural refinement, resulting in a decrease in grain size from about 411 μm down to 3.92 μm for MMC with 5 wt% of SiC. Consequently, the best combination of the ultimate tensile strength (UTS) (∼244 MPa) and total elongation (∼8.9 %) was obtained for the hot extruded composite containing 3 wt% SiCp. The prevailing strengthening mechanisms are supposed to be particle strengthening mechanism in the as-cast condition and coefficient of thermal expansion (CTE), Orowan, and Hall-Petch mechanisms in the as-extruded condition. Obviously, adding SiC p and employing hot working lead to significant increase in ultimate compressive strength (from 180 MPa to 321 MPa for 5 wt%). [ABSTRACT FROM AUTHOR]

Commercial pure Mg specimens were processed through equal channel angular pressing (ECAP) using two dies with die angles of 90° and 120°. Mg billets were processed up to four passes via different route types. Machine learning (ML) techniques were adopted to estimate the ECAP parameters and verify the experimental findings. Several ML techniques were employed to estimate the effect ECAP parameters of pure Mg on microstructural evolution, Vicker’s microhardness (HV), and tensile properties for ECAP billets and their as-annealed (AA) counterparts. Electron back-scatter diffraction (EBSD) was applied to determine the structural evolution and crystallographic texture both prior to and following the ECAP process for the Mg billets. EBSD analysis showed that route Bc is the most effective route in grain refinement, and four passes of route Bc experienced a significant refinement of 86% compared to the AA condition. Furthermore, the crystallographic texture showed that four passes of route Bc produced the most robust texture that was greater than 26.21 times random. ML findings revealed that the grain size demonstrated a strong correlation of −0.67 with rising number of passes, while ϕ affected the grain size strongly with 0.83. When adopting a 90°-die to accumulate the plastic strain up to 4Bc, the subsequent HV was indeed 111% higher than that of the AA equivalent. From ML findings it was clear that the number of passes was the most significant parameter on the Mg HV values, while ECAP channel angle (ϕ) revealed high correlation factor with HV values as well. Furthermore, four passes of route Bc with ϕ = 90° and 120° led to a significant increase of the tensile strength by 44.7%% and 35.7%, respectively, compared to the AA counterpart. ML findings revealed that the tensile strength was affected by the increasing number of passes with a strong correlation of 0.81, while affecting ductility moderately with 0.47.

This study investigates the sub-structure of IF steel in three conditions: cold rolled, statically recovered, and warm rolled. After both cold and warm rolling, the steel exhibits the typical 〈110〉//RD and 〈111〉//ND fiber textures. Considering the short-range misorientation gradient ∆θ/∆x to assess locally stored energy variations, it was observed that 〈111〉//ND grains exhibit significantly higher gradients than 〈001〉//ND grains in all conditions. In the statically recovered conditions, the ∆θ/∆x values are significantly reduced compared to the cold rolled condition, but these values are significantly higher than those of the dynamically recovered after warm rolling. The strongly reduced orientation gradients in the 〈111〉//ND grains after warm rolling may reduce the nucleation potency of these orientations in the ensuing recrystallization. This study enhances our knowledge of deformation microstructure as a function of rolling temperature and is relevant in explaining reported differences in annealing textures during static recrystallization after cold vs warm rolling. [Display omitted] [ABSTRACT FROM AUTHOR]

In 1969, Rice and Tracey proposed that the rate of void growth during ductile failure is a strong function of the hydrostatic stress state. Numerous in-situ x-ray computed tomography (XCT) studies demonstrated that the average rate of void growth is well-predicted by modified versions of the Rice-Tracey equation. However, recent in-situ XCT studies of void growth demonstrated that individual voids grow in highly heterogeneous manners in a way that is not predicted by Rice-Tracey or similar models. Model-based studies using crystal plasticity finite element (CP-FE) suggest that local effects of grain orientation play a strong role during void growth, but we lack experimental data to test this hypothesis. The present study leverages recent advances in laboratory-based diffraction contrast tomography (Lab-DCT) and in-situ XCT to systematically examine the effects of grain orientation on void growth experimentally in an Al-2219 alloy. CP-FE modeling was used to assess the local stress states associated with voids and their influence on void growth rates. These data indicate that void growth is not simply controlled by the local hydrostatic stress or stress triaxiality. Additionally, no clear relationship between void growth rates and grain orientation were observed. Instead, void growth rates were highly stochastic in ways that could not be directly linked to the local stress or strain states. The combination of experimental and modeling data suggests that our current assumptions regarding the mechanisms of void growth are flawed and that additional factors, which may include the local dislocation density, affect the rate of void growth. [Display omitted] [ABSTRACT FROM AUTHOR]

Aligning the hard phase has always been a great challenge in fabricating bulk nanocomposite magnets due to the high soft-phase fractions. In this work, anisotropic bulk Pr2Fe14B/α-Fe nanocomposite magnets have been fabricated from amorphous precursors by high-pressure thermal compression deformation. The synthesised magnet exhibits an ultrastrong magnetic anisotropy with a high soft-phase fraction of ∼29 wt.% and a dual-morphology grain structure that consists of equiaxed and lath-shaped grains. The anisotropy is originated from the strong (00l) crystallographic texture for Pr2Fe14B nanocrystals on account of its preferential nucleation and growth during the deformation with high stress and large strain. This study is favourable for the development of bulk nanocomposite magnets with superior energy products on the premise of high soft-phase fractions. [ABSTRACT FROM AUTHOR]

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AlSi7Mg0.6 alloy is the most widely used cast alloy for aerospace and automotive applications. Therefore, it is essential to explore the effect of scanning strategy parameters on the final part properties in the laser powder bed fusion (L-PBF) process. The effect of stripes and chessboard strategies parameters such as stripe length, rotation angle, and chessboard island size on mechanical and microstructural properties of L-PBF processed AlSi7Mg0.6 alloy is studied. The evolution of the residual stresses is also investigated in the longitudinal and transverse directions. Cooling rates are also estimated using the cell size within the melt pool. Three distinct regions (i.e., fine, coarse, and heat-affected zone) within the melt pool corresponding to different cooling rates could be identified based on Si morphology. The texture of the final material can be tailored by changing the scanning strategies. This study comprehensively presents the results concerning porosity, mechanical properties, crystallographic texture, cooling rates, grain morphology, and residual stresses for additively manufactured AlSi7Mg0.6 alloy. [ABSTRACT FROM AUTHOR]

The present paper investigates the role of parent phase topology on a crystallographic variant selection rule. This rule assumes that product phase nuclei appear at certain grain boundaries in the parent structure, such that a specific crystallographic orientation relationship is observed with both parent grains at either side of the grain boundary. The specific crystallographic orientation correspondence considered here is the Young–Kurdjumow–Sachs (YKS) orientation relationship <112>90° (which exhibits 24 symmetrical equivalents). The aforementioned relationship is characteristic of phase transformations in low-carbon steel grades. It is shown that, for different parent phase textures, ~20% of the grain boundaries comply with the double YKS condition allowing for a tolerance of 5°, ignoring the presence of topology in the parent phase microstructure. The presented model allows for connecting the presence of a specific parent phase topology with the condition of the double YKS variant selection rule in a number of practical cases: (i) for hot rolled Ti–Interstitial Free (IF) steel with and without Mn addition, (ii) for cold rolled IF steel exhibiting very strong texture memory after forward and reverse α ⇌ γ phase transformation and (iii) for a martensitic transformation in a Fe–8.5% Cr steel. It is shown that the double YKS variant selection criterion may explain several specific features of the observed transformation textures, while assuming a non-correlated arbitrary pair topology of the parent austenite structure (implying that for N parent orientations N/2 pairs are selected in an arbitrary manner). [ABSTRACT FROM AUTHOR]

The development of uniform tensile properties in cold-rolled BCC metals is generally achieved by annealing. The final microstructure of these components is typically characterized as having a rather coarse microstructure and therefore lower tensile properties. Cross-rolling offers a great potential of homogenizing the microstructure without losing the benefits of the rolled microstructure and crystallographic texture. The research summarized below examines the effect of cross-rolling and an austempering heat treatment on the mechanical properties of the AISI 8670 steel sheets. Comparison with the conventional production methods was performed to quantify the efficiency of the new deformation and heat treatment approach. The results clearly indicate that the combination of cross-rolling and low temperature austempering generates favorable isotropic mechanical properties by creating uniform strength of α and ε fiber textures and homogeneous lower bainitic microstructure. Increases in UTS and toughness of 40% and 57% respectively were systematically obtained with the new combination of deformation path and heat treatment. [ABSTRACT FROM AUTHOR]

The effect of crystallographic texture and deformation rate on the deformation behavior of titanium alloy VT16 after annealing at 700 – 880°C is studied. The compressive tests are performed at deformation rates 1, 10, 100, and 1000 mm/min. The stress-strain curves are plotted. The ultimate strain is determined. The microstructure of the alloy and its texture are studied using pole figures (PF) and orientation distribution functions (ODF). It is shown that the presence of an α-phase with axial texture 10 1 ¯ 0 lowers the yield strength and the flow stress of the alloy in the hardening range and the peripheral tensile stresses of the free surface of the compressed specimens, which raises the deformability of the alloy under compression. Elevation of the temperature of the specimens with growth of the deformation rate lowers the yield stress of the alloy, which also improves the deformability of the alloy under compression. [ABSTRACT FROM AUTHOR]

The epitaxial growth of dendrites, which often results in a strong texture, is the most common phenomenon during the laser additive manufacturing process. In this study, the epitaxial growth of dendrites and texture evolution in three directions were studied by changing the z-increment, pulse period, and track offset, respectively. The influence of the molten pool interface on the growth and competition of dendrites is analyzed. Both green grains (<110> // BD) with rotated cube texture in the molten pool overlapping zones and red grains (<100> // BD) with fiber texture in the molten pool center zones coexist for different z-increment samples, forming the typical sandwich texture feature. In a short pulse period, the dendrites can grow directly epitaxially and form the strong fiber texture due to gentle interface and short distance. With the decrease of the track offset, the molten pool morphology changes from flat to narrow and deep. When θ is close to 90°, dendrites grow along the secondary dendrite arms at the overlapping zone, forming V-shape grains. This work also provides a promising method for texture customization for laser additive manufacturing. [ABSTRACT FROM AUTHOR]

The crystallographic texture of the whole valves of bivalve mollusks from the family Unionidae Unio pictorum Linnaeus, 1758 and Anodonta cygnea Linnaeus, 1758 is studied using pole figures measured using neutron diffraction. The use of neutron diffraction, in contrast to X-rays, makes it possible to study the valves without destroying them. Thus, we can discuss the study of the global texture of the entire valve. It was revealed that the pole figures of aragonite in the valves repeat their shape. The pole density maxima for U. pictorum from the Danube Delta and the Gulf of Finland in the Baltic Sea, living at different salinities and temperatures, differs by 0.41 mrd. The maximum value of the crystallographic texture for A. cygnea from the Danube Delta was also measured (5.07 mrd). In terms of texture sharpness, it surpasses the shell of marine bivalve mollusks, which are partially or completely composed of aragonite. Although U. pictorum and Mya arenaria Linnaeus, 1758 have different microstructures, their pole figures are very similar in isolines pattern, but differ in pole density maxima. No relationship was found between the crystallographic texture and the microstructure in U. pictorum. In addition, we report good qualitative agreement between aragonite X-ray pole figures of Sinanodonta woodiana Lea, 1834 from the Czech river Luznice, and neutron pole figures of U. pictorum from the Danube Delta. [ABSTRACT FROM AUTHOR]

Highly textured Heusler alloy Mn44.7Ni43.5Sn11.8 ribbons were prepared by melt spinning. The magnetocaloric properties were evaluated by the direction of the magnetic field along the ribbon surface and perpendicular (H∥ and H⊥, respectively) for the same sample with the field up to 10 and 15 kOe. While the maximum magnetic entropy changes only a little difference (5%), the hysteresis loss (HL) and net refrigerant capacity (RC) have been significantly affected by the crystallographic texture of the magnetic field of 10 kOe. The amount of the RC reduces about 10% (H⊥) and 30% (H∥) due to the HL, respectively. The highly textured Mn-Ni–Sn melt-spun ribbons can be potentially applied in industrial magnetic refrigeration. [ABSTRACT FROM AUTHOR]

Accumulative roll bonding (ARB) is a severe plastic deformation (SPD) technique that has been extensively used in a wide range of metals to improve their mechanical properties. In particular, ARB processed materials display an increase in both yield and ultimate tensile strength, since the SPD processing induces a remarkable grain refinement. In precipitation-hardened alloys, such as aluminum 7075, this leads to a synergistic effect which further enhances strength. Although the reported results are promising for high-strength applications, thermal stability of the microstructure after processing remains an open question. In this paper, we present an investigation of the thermal stability of the texture, microstructure, and mechanical properties of Al-7075 samples processed by ARB to an equivalent Von Mises strain of 240%. After processing, yield and tensile strength displayed improvements of 30% and 20% respectively over the T6 condition. Crystallographic texture was found to depart from the rotated cube component to Dillamore/Taylor and Goss components. Several annealing heat treatments ranging from 373 to 673 K (100–400 °C) were carried out and it was found that the improved mechanical properties are stable up to 423 K (150 °C). The texture was found to slowly revert to a rotated cube with increasing temperature. The results are discussed in terms of the combination of strength and formability as calculated by the Lankford parameter using the visco-plastic self-consistent code (VPSC).

In the current work, mild steel used in shipbuilding applications was friction-stir-welded (FSWed) with the aim of investigating the microstructure and mechanical properties of the FSWed joints. Mild steel of 5 mm thickness was friction-stir-welded at a constant tool rotation rate of 500 rpm and two different welding speeds of 20 mm/min and 50 mm/min and 3° tool tilt angle. The microstructure of the joints was investigated using optical and scanning electron microscopes. Additionally, the grain structure and crystallographic texture of the nugget (NG) zone of the FSWed joints was investigated using electron backscattering diffraction (EBSD). Furthermore, the mechanical properties were investigated using both tensile testing and hardness testing. The microstructure of the low-welding-speed joint was found to consist of fine-grain ferrite and bainite (acicular ferrite) with an average grain size of 3 µm, which indicates that the temperature experienced above A1, where a ferrite and austenite mixture is formed, and upon cooling, the austenite transformed into bainite. The joint produced using high welding speed resulted in a microstructure consisting mainly of polygonal ferrite and pearlite. This could be due to the temperature far below A1 experienced during FSW. In terms of joint efficiency expressed in terms of relative ultimate tensile, the stress of the joint to the base material was found to be around 92% for the low-speed joint and 83% for the high-welding-speed joint. A reduction in welding was attributed to the microstructure, as well as the microtunnel defect formed near the advancing side of the joint. The tensile strain was preserved at 18% for low welding speed and increased to 24% for the high welding speed. This can be attributed to the NG zone microstructural constituents. In terms of crystallographic texture, it is dominated by a simple shear texture, with increased intensity achieved by increasing the welding speed. In both joints, the hardness was found to be significantly increased in the NG zone of the joints, with a greater increase in the case of the low-welding-speed joint. This hardness increase is mainly attributed to the fine-grained structure formed after FSW. [ABSTRACT FROM AUTHOR]

Aluminum (Al) and its alloys are the second most used materials spanning industrial applications in automotive, aircraft and aerospace industries. To comply with the industrial demand for high-performance aluminum alloys with superb mechanical properties, one promising approach is reinforcement with ceramic particulates. Laser powder-bed fusion (LPBF) of Al alloy powders provides vast freedom in design and allows fabrication of aluminum matrix composites with significant grain refinement and textureless microstructure. This review paper evaluates the trends in in situ and ex situ reinforcement of aluminum alloys by ceramic particulates, while analyzing their effect on the material properties and process parameters. The current research efforts are mainly directed toward additives for grain refinement to improve the mechanical performance of the printed parts. Reinforcing additives has been demonstrated as a promising perspective for the industrialization of Al-based composites produced via laser powder-bed fusion technique. In this review, attention is mainly paid to borides (TiB2, LaB6, CaB6), carbides (TiC, SiC), nitrides (TiN, Si3N4, BN, AlN), hybrid additives and their effect on the densification, grain refinement and mechanical behavior of the LPBF-produced composites. [ABSTRACT FROM AUTHOR]

The structure and mechanical properties of tough-pitch copper are studied after alternating elastoplastic deformation (bending). It is shown that alternating bending of a 3-mm-thick strip of tough-pitch copper raises the microhardness and produces a gradient of its values, i.e., the microhardness is minimum in the middle (with respect to the thickness) part of the strip and maximum near its surfaces. After the first pass of alternating bending the conventional yield strength of the strip increases by a factor of 1.5 without degradation of the elongation. The structural factors affecting the variation of mechanical properties of tough-pitch copper under alternating bending are determined. [ABSTRACT FROM AUTHOR]

The crystallographic aspects of the phase transformations in zirconium alloys under compressive stresses are studied, and the changes in the sizes of cladding tubes, rods, and rings made of E110opt and E125 alloys at compressive stresses and without them are determined. The temperature of the onset of the phase transformation on heating is found to shift toward low temperatures under a load applied to a cladding tube ring in the diametral direction, and a noticeable strain leading to the appearance of ellipticity of the rings are detected. Some of the versions of the Burgers orientation relationship are operative during the reverse β‒α phase transformation under compressive stresses, which manifests itself in the suppression of growth of texture maxima in the applied load direction during cooling. Deformation is shown to be accelerated on heating in the two-phase α + β region under compressive stresses, and the parameters of high-temperature creep are calculated using the temperature dependences of the strain. [ABSTRACT FROM AUTHOR]

In this study, the simultaneous significance of the crystallographic texture and nanostructuring on the cytocompatibility of as‐cast (Ti55Zr25Nb10Ta10)98.5‐Ag1.5 alloy (at. %, TZNT‐Ag1.5), subjected to cold rolling up to 90% reduction, along with the changes of Young's modulus and hardness under cold rolling were investigated. For this purpose, the as‐cast and cold‐rolled TZNT‐Ag1.5 alloy test specimens were analyzed by XRD, TEM, HRTEM, SEM, contact angle, nanoindentation, and OM techniques. Moreover, to evaluate the effect of severe cold deformation on the biocompatibility, MG‐63 osteoblastic cell was cultured on the surface of 90% cold‐rolled and as‐cast test specimens of TZNT‐Ag1.5 alloy. The results showed that severe cold deformation was led to fast grain refinement of β grains of the as‐cast TZNT‐Ag1.5 alloy in the range of 50–100 nm. In addition to the nanostructuring, upon severe cold deformation, the ‐fiber (<111>// normal direction) texture was formed and after 90% reduction, the (111)<1 1¯0> γ‐fiber component was strengthened. The micro‐hardness and reduced Young's modulus are 235 ± 5.29, 246 ± 1.73, 271 ± 4.0, and 283 ± 6.25 (HV); and 73.725 ± 1.70, 83.98 ± 5.10, 81.26 ± 6.55, and 88.66 ± 7.16 (GPa) for TZNT‐Ag1.5 (as‐cast), TZNT‐Ag1.5 (20%CR), TZNT‐Ag1.5 (50%CR), and TZNT‐Ag1.5 (90%CR) test specimens, respectively. Further, with increasing the cold deformation degree, the dislocation density of TZNT‐Ag1.5 alloy increased as this parameter is 2.79 × 1015 (m−2) for the 90%CR test specimen. On the other hand, the values of the contact angle for the 90%CR test specimen (46.2 ± 3.5°) exhibit a higher hydrophilic and wettable surface as compared to the other studied test specimens. After 5 days of incubation, osteoblastic cells on the surface of the 90% cold‐rolled TZNT‐Ag1.5 test specimens revealed significant differences in cell proliferation and differentiation as compared to the as‐cast alloy test specimens and/or CP‐Ti. Finally, because the maximum orientation intensities were generally <3, it was deduced that grain refinement rather than the crystallographic texture plays a significant role in improving the surface biocompatibility of the new TZNT‐Ag1.5 alloy. [ABSTRACT FROM AUTHOR]

Research into the plastic deformation process in the lattice structure produced by selective laser melting (SLM) of powder from 316L austenitic stainless steel was carried out by compression tests along the build direction and perpendicular to it. The resulting stress–strain curve parameters showed anisotropic behaviour of such a structure. Differences in the crystallographic texture of both the bulk and lattice samples were also discovered, so the direct use of the mechanical properties of the bulk materials for calculation of lattice structure deformation behaviour would be incorrect. To overcome this limitation, the crystal plasticity finite element model based on the DAMASK framework was used, and the mechanical properties of the lattice structure material were calculated with respect to the crystallographic texture differences. In turn, the data obtained for the bulk material was used to model the plastic deformation of the lattice structure and these results are in good agreement with the experimental data. Therefore, it is possible to use the bulk material data for forecasting the lattice structure deformation. The resultant model allows for the prediction of the deformation behaviour of the lattice ribs.

This study extends the second-order attenuation (SOA) model for elastic waves in texture-free inhomogeneous cubic polycrystalline materials with equiaxed grains to textured polycrystals with ellipsoidal grains of arbitrary crystal symmetry. In term of this work, one can predict both the scattering-induced attenuation and phase velocity from Rayleigh region (wavelength >> scatter size) to geometric region (wavelength << scatter size) for an arbitrary incident wave mode (quasi-longitudinal, quasi-transverse fast or quasi-transverse slow mode) in a textured polycrystal and examine the impact of crystallographic texture on attenuation and phase velocity dispersion in the whole frequency range. The predicted attenuation results of this work also agree well with the literature on a textured stainless steel polycrystal. Furthermore, an analytical expression for quasi-static phase velocity at an arbitrary wave propagation direction in a textured polycrystal is derived from the SOA model, which can provide an alternative homogenization method for textured polycrystals based on scattering theory. Computational results using triclinic titanium polycrystals with Gaussian orientation distribution function (ODF) are also presented to demonstrate the texture effect on attenuation and phase velocity behaviors and evaluate the applicability and limitation of an existing analytical model based on the Born approximation for textured polycrystals. Finally, quasi-static phase velocities predicted by this work for a textured polycrystalline copper with generalized spherical harmonics form ODF are compared to available velocity bounds in the literature including Hashin−Shtrikman bounds, and a reasonable agreement is found between this work and the literature.

A high-priority target in the design of new metallic materials for load-bearing implant applications is the reduction of Young’s modulus approximating that of cortical bone in the predominant loading direction. Here, we explore how directionally preferential bulk elastic properties of implant materials are achieved by harnessing elastic anisotropy. Specifically focusing on recently proposed biocompatible refractory high-entropy alloys (RHEAs) in the body-centered cubic structure, we conduct systematic density-functional theory calculations to investigate the single-crystal elastic properties of 21 Ti-containing RHEAs. Our results provide evidence that the valence electron count has a dominant influence on elastic anisotropy and crystal directions of low Young’s modulus and high torsion modulus in the RHEAs. By means of modeling the orientation distribution function for crystallographic texture, we examine the effect of non-random texture on the anisotropic poly-crystalline Young’s modulus and torsion modulus with varying texture sharpness. We adopt fiber textures that can result from rolling and distinct texture orientations that can form during rapid directional solidification. We discuss the potential for lowering Young’s modulus in the RHEAs by using single crystals or textured aggregates. Furthermore, we prepare four of the theoretically considered alloys by arc-melting and report their lattice parameters, quasi-isotropic Young’s moduli, and Wickers hardnesses.

Flexible pipelines connect offshore platforms to subsea production systems due to their high flexibility, applicability, and recycling. Flexible armor layers in flexible pipelines are constructed using the parallel helical wrapping of several rectangular wires. The complex stress modes to which pipelines are subjected provide complex failure modes that are mostly unpredictable, requiring expensive pipeline integrity verification methods. This work investigates texture and microstructure evolution in pearlite-drawn wires due to different heat treatments. The material was subjected to annealing and isothermal heat treatments to obtain changes in its microstructure and texture. The changes were characterized using SEM, XRD, and EBSD techniques. Samples were subjected to tensile testing to evaluate their mechanical properties. This work revealed that annealing and isothermal treatments mainly modify the material microstructure, whereas annealing provides a material with grains with ease of deformation. In contrast, isothermal treatment provides grain growth with high internal energy and more deformation resistance. Annealing increases the intensity of all texture components, while isothermal treatment reduces intensity. These findings provide insights into the relationship between material properties and heat treatments, which can be used to optimize the design and performance of flexible pipelines, thereby reducing the need for expensive integrity verification methods.

In the current study, the effect of equal channel angular pressing parameters such as die route type and die angle were studied. Billets of pure magnesium (Mg) were processed successfully through up to 2-passes of different routes, A, Bc, and C, using equal channel angular pressing dies with different internal angles of 90° and 120° at 225°C. The crystallographic texture and microstructural evolution were investigated using electron back-scatter diffraction. The Vickers microhardness and tensile properties were investigated, analyzed, and linked to the microstructure and crystallographic texture as well. The as-annealed condition revealed relatively coarse equiaxed grains coupled with some extra-elongated grains with average grain size of 6.338 µm. Processing through 2-passes formed an ultrafine grain structure and recrystallized fine grains. This decrease in grain size was associated with hardness and tensile strength enhancement as compared with the as-annealed Mg counterpart. ECAP processing through the 90° die revealed that 2-passes of route Bc was more effective in grain refinement compared to routes A and C, and it reduced the average grain size by 76.45% compared to the as-annealed counterpart. On the other hand, for the ECAP die with 120°, route A was more effective in grain refinement compared to the other routes. Processing through 2-passes of route C resulted in a stronger texture compared to the other routes with momentous rotation for the texture components. Processing of 2-A, 2-Bc, and 2-C through the 90°-die revealed an increase in the Vickers Hardness (HV) of 76.9, 96, and 84.6%, respectively, compared to the AA counterpart. In addition, the tensile findings revealed that the 90°-die resulted in higher ultimate tensile strength coupled with a drop-in ductility compared to the 120°-die. Furthermore, ECAP processing through the 90°-die led to improvement in the ultimate tensile strength by 14.1, 38.4, and 43.75%, respectively, coupled with improving the Mg ductility by 80.9, 73.5, and 47.6% through processing via 2-A, 2-Bc, and 2-C, respectively, compared to the as-annealed counterpart.

This work investigates the role of grain size and recrystallization texture in the corrosion behavior of pure iron in 0.1 M sulfuric acid solution. Annealing heat treatment was applied to obtain samples with different average grain sizes (26, 53 and 87 µm). Optical microscopy, X-ray diffraction and electron backscatter diffraction techniques were used to characterize the microstructure. The EBSD data analysis showed ferrite phase with no inclusions and very low geometrically necessary dislocation density, indicating strain-free grains constituting all samples. The crystallographic texture analysis of the samples revealed that the 26 µm grain size sample had a high volume fraction of {111} oriented grains parallel to the sample surface, while other samples exhibited nearly random crystallographic texture. The electrochemical results from potentiodynamic polarization and electrochemical impedance spectroscopy showed a decrease in corrosion resistance from 87 µm to 53 µm grain size sample and then an increase for the 26 µm grain size sample. This increase was attributed to the dominant effect of recrystallization texture on the corrosion behavior of the sample. The cathodic hydrogen evolution reaction kinetics was found to play a decisive role in the corrosion behavior of iron.

Evolution of the texture of an Al–Cu composite after addition of alumina particles was investigated in details using X-Ray Diffraction (XRD) method. Composite samples were produced by the Accumulative Roll Bonding (ARB) and alumina particles were uniformly added to the composite using anodizing technique. The process was accompanied by cutting, stacking and rolling the lamellar materials up to seven times. In early stage of ARB, a shear texture close to the Rotated Cube formed for the Al side. This texture development was also confirmed by microstructural investigation on shear bands during deformation employing optical and scanning electron microscopy. In the last two cycles, a nearly random orientation of grains was developed. For the Cu side, however, the recrystallized Cube texture component was prominent for early ARB cycles due to the recrystallization phenomenon. Moreover, a mixture of rolling and recrystallized texture was detected for the Cu side at higher ARB cycles. Furthermore, evaluation of the grain boundaries showed an increase in the number of high angle grain boundaries for the final ARB cycles in both Al and Cu sides, confirming the occurrence of grain refinement during ARB. Localized particle deformation zone (PDZ) around alumina particles was also proposed to have a contribution to textural evolution of the composite.

This paper deals with the investigation of crystallographic texture evolution and the associated change in acoustic birefringence during plastic deformation under uniaxial tension of metal alloy. Results of computer simulation for orthotropic α-Fe and γ-Fe polycrystalline aggregates are compared with experimental data for different steels. The increment in acoustic birefringence of shear elastic waves caused by changes in the elastic properties due to plastic deformation is found to be positive for the α-Fe polycrystalline aggregate with a bcc lattice and negative for the γ-Fe one with a fcc lattice. This effect is concluded to be associated with the difference between bcc and fcc lattices, having different slip planes and slip directions. Scattering of initial orthotropic texture and critical shear stress are also found to affect the changes in the effective elastic properties and, accordingly, the quantitative increment in acoustic birefringence. The mentioned factors should be taken into account when assessing damage of metal alloy by the acoustic birefringence technique. [ABSTRACT FROM AUTHOR]

Nickel-based superalloys are widely used for structural applications due to their excellent mechanical properties and very good corrosion resistance. In the present study, the texture and the deformation behavior of heat-treated nickel-based superalloys (Inconel 718) were examined. The initial textures are characterized by the EBSD measurements and they are correlated with the deformation behavior. The mechanical behavior of Inconel 718 is predicted by three-dimensional finite element simulations. Numerical finite element simulations are compared and validated with the experimental results. [ABSTRACT FROM AUTHOR]

Polycrystalline materials, such as metals, are composed of heterogeneously oriented crystals. Observed crystal orientations are modelled as a sample from an orientation distribution function (ODF), which determines a variety of material properties and is therefore of great interest to practitioners. Observations consist of quaternions, four‐dimensional unit vectors reflecting both orientation and rotation of a single crystal. Thus, an ODF must account for known crystal symmetries as well as satisfy the unit length constraint. A popular method for estimating ODFs nonparametrically is symmetrized kernel density estimation. However, disadvantages of this approach include difficulty in interpreting results quantitatively, as well as in quantifying uncertainty in the ODF. We propose to use a mixture of symmetric Bingham distributions as a flexible parametric ODF model, inferring the number of mixture components, the mixture weights, and scale and location parameters based on crystal orientation data. Furthermore, our Bayesian approach allows for structured uncertainty quantification of the parameters of interest. We discuss details of the sampling methodology and conclude with analyses of various orientation datasets, interpretations of parameters of interest, and comparison with kernel density estimation methods. [ABSTRACT FROM AUTHOR]

The evolution of microstructure and mechanical properties in AISI 8630 low-alloy steel subjected to inertia friction welding (IFW) have been investigated. The effects of three critical process parameters, viz. rotational speed, friction and forge forces, during welding of tubular specimens were explored. The mechanical properties of these weld joints, including tensile and Charpy V-notch impact were studied for determining the optimum welding parameters. The weld joints exhibited higher yield strength, lower hardening capacity and ultimate tensile strength compared to base metal (BM). The maximum strength and ductility combination was achieved for the welds produced under a nominal weld speed of ~ 2900–3100 rpm, the highest friction force of ~ 680–720 kN, and the lowest axial forging load of ~ 560–600 kN. The measured hardness distribution depicted higher values for the weld zone (WZ) compared to the thermo-mechanically affected zone (TMAZ), heat-affected zone (HAZ) and BM, irrespective of the applied welding parameters. The substantial increase in the hardness of the WZ is due to the formation of microstructures that were dominated by martensite. The observed microstructural features, i.e. the fractions of martensite, bainite and ferrite, show that the temperature in the WZ and TMAZ was above Ac3, whereas that of the HAZ was below Ac1 during the IFW. The fracture surface of the tensile and impact-tested specimens exhibited the presence of dimples nucleating from the voids, thus indicating a ductile failure. EBSD maps of the WZ revealed the formation of subgrains inside the prior austenite grains, indicating the occurrence of continuous dynamic recrystallisation during the weld. Analysis of crystallographic texture indicated that the austenite microstructure (i.e. FCC) in both the WZ and TMAZ undergoes simple shear deformation during IFW. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The possibility of synthesizing textured barium hexaferrite films on silicon wafers with Ti, Al2O3/Ti, or Al2O3/TiO2 barrier layers was studied. X-ray diffraction (XRD) showed that, after crystallization annealing, the hexaferrite phase with the (00l) preferred orientation was formed only when there was contact between BaFe12O19 and Al2O3. The hexaferrite microstructure in these samples, according to atomic force microscopy (AFM), is represented by rounded grains, which are typical of films where the hexagonal axis is perpendicular to the surface plane. Titanium in a BaFe12O19/Al2O3/Ti sample was partially oxidized during the synthesis. This process and the associated phase transformations in TiO2 are assumed to induce mechanical stress in the structure and, as a consequence, the formation of macroscopic defects (bulges). Complete pre-oxidation of the titanium film produced a textured BaFe12O19 structure without macroscopic defects. [ABSTRACT FROM AUTHOR]

In the present work, crystal plasticity simulations using the fast Fourier transform (FFT) based Düsseldorf advanced material simulation kit (DAMASK) are performed to provide new insights on choosing the value of interaction parameter in the localisation equation of the visco-plastic self-consistent (VPSC) model. A statistical criterion based on the distribution of shear rates ( γ ˙ s ) at each material point is obtained using DAMASK, which enables the judicious selection of the interaction parameter in the VPSC model. Subsequent large-scale texture simulations via VPSC indicated an excellent match between experimental and simulated textures, which establishes the effectiveness of the proposed approach of learning from full-field models and using it in the mean-field, less computationally expensive VPSC model for performing efficient texture simulations. [ABSTRACT FROM AUTHOR]

SEM and EBSD techniques are used to evaluate hydrogen induced cracking susceptibility in API X70 pipeline steels produced by thermo-mechanical controlled process (TMCP) in laboratory scale. Based on the observations, there is no dominant texture in the specimens and the grains are randomly distributed. Different TMCP parameters and rolling processes generates different grain size, and grains are often elongated along the rolling direction. The results also show that cooling rate is another factor affecting the grain size. A high cooling rate does not allow the grains to grow. The reason for the transgranular type of cracking might be the strong grain boundaries in ambient temperatures which prevents the intergranular cracking. Based on experiments, the hydrogen environment does not have permanent effects on the mechanical properties of the investigated specimens. The electrochemical hydrogen charging experiment shows that the grain refinement improves the resistance to hydrogen embrittlement. [Display omitted] • Two different TMCPs were utilized to produce two new types of X70 pipeline steel. • Two TMCPs did not provide any dominant texture in tested specimens. • Two TMCPs and rolling processes generated different grain size and grains. • Hydrogen did not have permanent effect on the mechanical properties of specimens. • Grain refinement improved the resistance to hydrogen embrittlement. [ABSTRACT FROM AUTHOR]

The crystallographic texture of modern, subfossil and fossils (Upper Pleistocene) shells of the bivalves Mytilus galloprovincialis, modern and subfossil Mytilus trossulus, as well as modern and fossil (Upper Pleistocene) Ostrea edulis are studied using neutron diffraction. It is revealed that shells of mussel species of different ages are characterized by a high ordering of calcite crystals—a sharp texture. Aragonite crystals are poorly distributed, depending on the shape of the valves. In a warm, dry climate, shells of M. galloprovincialis undergo stratification of the shell matter, which violates the crystallographic texture. Under land conditions, the ordering of calcite crystals in M. galloprovincialis shells decreases. In the subfossil M. trossulus and fossil M. galloprovincialis and O. edulis, the crystallographic texture intensity of the calcite and aragonite changes over hundreds and thousands of years. [ABSTRACT FROM AUTHOR]

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.

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 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.

Among several severe plastic deformation (SPD) methods, the Equal Channel Angular Pressing (ECAP) process is one of the most popular. This process's main characteristic is producing materials with ultra-fine or nanometric grains. Due to these microstructural changes, it is possible to improve mechanical properties such as strength and ductility. In this perspective, the aim of the present work was to evaluate the variations of the mechanical hardness property associated with microstructural and textural changes of pure copper as a function of its processing by SPD via ECAP. For this, the material was submitted to four passes through routes A (the sample is repetitively pressed without any rotation between each pass) and Bc (the sample is rotated in the same sense by 90° between each pass) at cold and warm temperatures. Through the obtained result, it was verified that the ambient temperature of the Bc route was the one that promoted greater homogeneity in the microstructure and weakening of the texture after the fourth pass. On the other hand, warm processing of copper by ECAP promoted a softening of the samples and a homogeneous distribution of hardness in both routes.

Crystallographic texture is related to the anisotropy or isotropy of material physical properties, including mechanical performance. The crystallographic effect in micromachining is more significant than that in macro-processing owing to that the depth of the cut and the grain size are in the same order. It is of great significance to model the crystallographic texture evolution induced by mechanical and thermal load during micro-machining to investigate the surface integrity and performance of the finished product. This study performed hot deformation experiments of Al alloy 7075 (AA7075) under various input parameters, including the temperature, temperature rate, stain rate, and strain, which was designed using the Taguchi method. Following that, crystallographic orientation of the samples before and after the deformation was tested using electron back-scattered diffraction (EBSD). Then, the crystallographic texture evolution was modeled with the parameters obtained by fitting a part of the experimental data. The crystallographic texture evolution of AA7075 under different levels of input parameters is studied and analyzed. Finally, the sensitivity of crystallographic orientation evolution to the process parameter is analyzed. The results indicate that these four input parameters have a significant impact on some crystallographic texture of the specimens. The proposed model is instructive in the future investigation of micromachining and microstructure evolution.

Additive manufacturing of metallic materials generates strong crystallographic textures, leading to anisotropic elastic properties on the macroscopic scale. The impact of the processing parameters on the resulting texture requires suitable techniques for the prediction and the experimental determination of elastic properties to exploit the anisotropy in the design process. Within this study mechanical as well as microstructure based approaches are applied on a batch of specimens manufactured from IN718 by selective laser melting to assess the elastic behavior on macroscropic scale. Tensile loading experiments and the impulse excitation technique are applied for the determination of elastic properties without additional constitutive data. Furthermore, the elastic behavior is estimated from single-crystal elastic properties and texture data measured by electron backscatter diffraction and high energy X-ray diffraction. The results of the applied approaches are discussed and compared, allowing also to assess the homogeneity of the elastic properties within the batch of specimens.