Cube Recrystallization Texture Research Articles

Origins of Cube Recrystallization Textures in Heavily Rolled High Purity Al

In high purity (4N) Al containing 50 ppm Cu, very strong cube textures can be developed by cold rolling 98 % and annealing at 500 °C. The orientation density in this material amounted to as much as 220 times random, i. e. about 3 times stronger than that observed in standard 4N Al. It is expected that the origins of cube textures should be most unambiguously clarified by using this material. Commercial hot bands of this materials were cold rolled 98 % to the thickness of 132 μm and isothermally annealed at 230 °C. Detailed EBSP analyses were made both on the rolling plane and on the longitudinal section at each stage of annealing. It was found that in the hot band of this high purity Al, cube orientations were mostly rotated away into other orientations due to low temperature hot rolling with high rolling reductions. Therefore, regions having cube orientations were very few. They were not present in the form of so called cube bands, which had been reported in previous investigations, but in the form of isolated, rather equi-axed recrystallized grains. After 98 % cold rolling, these remaining cube regions were fragmented, and further rotated away into other orientations, so that only very few cube oriented regions were observed in the cold rolled materials. However, it was from such deformed cube oriented regions that the most potential exact cube recrystallized grains were formed. They were nucleated much earlier and grew much faster than grains of other orientations.

The Influence of Texture and GBCD on Stress Corrosion and Intergranular Corrosion in 2024 Aluminum Alloy

The recrystallization texture, grain boundary character distribution (GBCD) and their influence on the stress corrosion cracking and intergranular corrosion of 2024 aluminum alloy were investigated. Results showed that the texture of Specimen A1 is characterized by the retained coldrolling texture; while Specimen A3 has strong recrystallized cube texture and high frequencies of CSL grain boundaries (especially S7), which shows high stress corrosion and intergranular corrosion resistance.

Effect of silver on cube texture formation in nickel substrate tapes

The effect of silver in pure nickel on the quality of the primary recrystallization cubetexture was investigated after intense cold rolling and annealing. Texture sharpness andthermal stability in the nickel tapes could be improved by micro-alloying with silver in therange of 100–500 at. ppm Ag. The sharpest cube texture was observed for theNi + 100 at. ppm Ag materialafter annealing at 550 °C (FWHM(111) = 4.4°). Further, the nickel oxide layer grown thereon had a sharp cube texture rotated by45° relative to the metallic substrate. Grain boundaries showed a typical zigzag image and thegrain form was fractal-like.

Quantitative analysis of texture evolution of cold-rolled direct-chill-cast and continuous-cast AA5052 and AA5182 aluminum alloys during isothermal annealing

The as-received direct-chill-cast (DC) and continuous-cast (CC) AA5052 and AA5182 hot bands were preheated at 454 °C for 4 hours, followed by cold rolling to an 80 pct reduction in thickness. The texture evolution of these cold-rolled samples during isothermal annealing was investigated by X-ray diffraction. The variation in texture volume fractions with annealing time was quantitatively analyzed by using the Johnson-Mehl-Avrami-Kolmogorov (JMAK) equation. The differences in recrystallization textures between the AA5052 and AA5182 alloys and between the DC and CC alloys were compared. It was found that the AA5052 alloy possessed a stronger cube recrystallization texture than the AA5182 alloy for the DC and CC materials. The recrystallization textures of the AA5182 alloy were affected strongly by the annealing temperature. As the annealing temperature increased, the cube recrystallization texture strengthened, whereas the R texture weakened. The annealing temperature had little influence on the recrystallization textures of the AA5052 alloy. The DC AA5052 and 5182 alloys also exhibited stronger cube recrystallization textures than the corresponding CC alloys. For the DC and CC AA5052 alloys, the n value in the JMAK-type equation increased with an increase in the annealing temperature, while the n values varied only slightly with the annealing temperature for the DC and CC AA5182 alloys.

Orientation-dependent stored energies in hot deformed Al–2.5%Mg and their influence on recrystallization

The dislocation densities in individual texture components of a hot, plane strain compressed, Al–2.5%Mg alloy have been determined by high resolution X-ray diffraction using recent methods for peak broadening interpretation. After deformation at 400 °C and strains up to 1.5 dislocation densities range from 2 to 20 × 10 13 m −2. Both high energy synchrotron (European synchrotron radiation facility, ESRF) transmission peak analysis and standard reflection line analysis show that the S {1 2 3}〈4 1 2〉 component develops significantly higher stored energies than the cube, brass {0 1 1}〈2 1 1〉 and Goss {0 1 1}〈1 0 0〉 components. After subsequent annealing to partial recrystallization, EBSD orientation maps over large areas demonstrate that the high energy S component is preferentially consumed by recrystallization. It is also shown that the development of the cube recrystallization texture is due to a nucleation frequency advantage, function of the applied strain.

BiTEP (biaxially textured electroplating): A novel route for making improved coatedconductors, based on a well established technique

We present a new technique for the deposition of Ni on cube textured Ni alloysubstrates. It is superior to the commonly used PVD and CVD coating methods andeasy to scale up from the laboratory to an industrial long length process. Thenew route, called ‘BiTEP’ (biaxially textured electroplating), where biaxiallytextured Ni alloy substrates are electrolytically plated with Ni, is shown to lead toan outstanding transfer of the texture from the substrate to the pure Ni layer.Several platings from 130 nm to1.5 µm thicknesswere made on Ni96W4, Ni87Cr6.5W6.5 and Ni90Cr10 substrates, applying different current densities during electroplating, from 0.2 to2 A dm−2. All investigated samples showed epitaxy between the substrates and the Ni film,independent of the layer thickness, the current density used for electroplating, and thesubstrate material.In Ni–W substrate tapes a sharp cube recrystallization texture with FWHM (111) of<5° was achieved, leading to a current density of1.35 MA cm−2 (77 K, self-field) in YBCO. Furthermore, commercially available constantan (Ni 44.4 wt%,Cu 54.19 wt%, the rest: Mn, Fe) from our partner ThyssenKrupp VDM was investigated.

The evolution of the cube recrystallization texture in cold rolled copper sheets

The S{123}〈634〉 deformation texture has often been addressed to be responsible for the cube {001}〈100〉 recrystallization texture in fcc metals from ∼40°〈111〉 rotational relation. After the 95% cold rolled copper sample was heated up to various temperatures at the rate of 2.5 K s −1 and quenched, the density of the S component was slightly lowered while that of the copper component {112}〈111〉 was decreased drastically. This result suggests indirectly that the decrease in the density of the copper component is closely linked to the increase in the cube component. Electron backscatter diffraction (EBSD) studies also indicated that the cube rerystallization texture was linked with the {112}〈111〉 deformation texture. The results have been discussed based on the strain energy release maximization (SERM) model, in which the recrystallization texture is determined so that release of the strain energy due to dislocations can be maximized during annealing.

Recrystallization in a Hot Deformed Al‐Mg‐Si Alloy: The Effect of Fine Precipitates

The recrystallization of an Al‐Mg‐Si alloy deformed by plane strain compression at 400°C and 1 s-1 has been studied. Fine particles are found to have a significant influence on the development of recrystallization textures. Annealing at 400°C, in the presence of Al‐Fe‐Si particles located on boundaries, results in a weak recrystallization texture. There is a clear indication that grain nucleation is associated with abnormal subgrain growth. The occurrence of this recovery process is analyzed by taking into account the particle pinning pressure and the orientation dependence of boundary energy and mobility. The cube recrystallization texture observed after annealing at 510°C is discussed in terms of the stability of Mg2Si and Al‐Fe‐Si precipitates.

Cube recrystallization textures in a hot deformed Al–Mg–Si alloy

The formation of cube recrystallization textures has been studied on Al–Mg–Si polycrystals deformed at 400 °C by channel die compression tests and annealed at 510 °C. A cube recrystallization texture was observed on samples presenting a very low fraction of cube volumes before and after deformation.

EBSD study of the development of cube recrystallization texture in Fe–50%Ni

EBSD study of the development of cube recrystallization texture in Fe–50%Ni

A study on the formation mechanisms of the cube recrystallization texture in cold rolled Fe–36%Ni alloys

The formation of sharp cube recrystallization texture after high cold rolling reductions in Fe–36%Ni has been studied by means of X-ray texture measurements and extensive transmission electron microscopy (TEM) observations, including orientation measurements even in highly deformed materials. In contrast to Cu and Al, this material shows only little recovery during cold deformation; therefore, the deformation structure can be studied in detail. After high cold rolling the cube grains present at the hot rolled state show the formation of cells and the development of a large orientation gradient inside cube bands. During recrystallization nucleation of cube grains proceeds at a high rate inside these structures. For low deformations cube grain nucleation seems to be inhibited due to the insufficient orientation gradient across the cells. Regions of other orientations show a much lower nucleation rate owing to their inappropriate microstructure. Thus, other recrystallization textures only develop if the cube nucleation is inhibited.

Nickel-refractory metal substrate tapes with high cube texturestability

The effect of different impurity levels in nickel on the quality ofthe primary recrystallization cube texture after intense cold rolling wasinvestigated. Texture sharpness and thermal stability in the 99.9 at% nickeltapes could be improved by micro-alloying with molybdenum and tungsten as wellas with niobium and tantalum. Furthermore, micro-alloying reduced thesusceptibility of the substrate materials against grain boundary grooving atprocessing temperatures in the range of about 800 °C. Highly alloyednickel with 5 at% tungsten was not susceptible to thermal etching effectsindependent of the processing route, i.e. melting or powder metallurgy. Cubetextures were obtained for different nickel-refractory metal alloys withcharacteristic in-plane orientations of FWHM: 4-8°.The performance of this group of substrate materials for coating with ceramicbuffer and superconductor layers could be proven by the achieved maximumcritical current density of 1.2 MA cm-2 at liquid nitrogen temperatureand zero magnetic field.

Role of shear band in texture control of Al-Mg alloys

Shear bands formed in Al-Mg alloys during cold rolling are nucleated on grain boundaries. Their mechanism of formation is different from that already proposed in the case of single crystals of the same alloy. Since recrystallized grains of non-cube orientations are nucleated on these shear bands during annealing, the development of cube recrystallization texture can be strongly suppressed by enhancing shear banding during cold rolling. Control of shear band thus provides a new fundamental technological tool to improve drawability of Al alloy sheets. In a microscopic scale, deformation in grain boundary regions also plays here a very important role, as in the case of the formation of {111}uvw recrystallization textures in low carbon steel sheets.

Formation of Recrystallization Cube Texture in High Purity Face-Centered Cubic Metal Sheets

Formation of Recrystallization Cube Texture in High Purity Face-Centered Cubic Metal Sheets

Formation of recrystallization cube texture in high purity face-centered cubic metal sheets

An investigation on recrystallization textures in high purity face-centered cubic (fcc) aluminum, copper, and nickel indicated that the cube texture is a unique dominant final texture. In a macroview of rolling deformation, a balanced activation of four slip systems can result in certain stability of some substructure with cube orientation in the deformed matrix. In the stable substructure the dislocation density is very low, and the dislocation configuration is rather simple in comparison to other orientations so that the cube substructure can easily be transformed into cube recrystallization nuclei by a recovery process. A high orientation gradient and correspondingly high angle boundaries to the deformed matrix are usually expected around the cube nuclei, which, therefore, grow rapidly. After the primary recrystallization, the size of cube grains is much larger than the grains with other orientations, which will be expensed as the cube grains grow further, so that the cube texture can finally become a dominant texture component.

Recrystallization texture in a cold rolled commercial purity aluminum: on the plausible macro- and micro-mechanisms

In the cold rolled commercial purity aluminum alloy AA1080, the most significant aspect of the recrystallization texture is the strengthening of the Cube {001}〈100〉 component. The increase is primarily attributed to the ‘frequency advantage’ of the Cube grains—i.e. the recrystallized Cube grains are higher in number but not larger in size. In general, Cube grains appear first and the deformed Cube regions have lower stored energies. The average spacing (along normal direction, ND) of the original hot band Cube regions is 450 μm, while average Cube band spacings after 60 and 80% deformations are 195 and 120 μm. Recrystallized Cube grains originate from these deformed Cube bands and an approximate estimation of the nucleation ability (the so-called nucleation factor of Cube or N C ) of the Cube bands is obtained from the geometrical relationship A C = N C d C / λ C , where A C , d C and λ C are the area fraction, average recrystallized Cube grain size and average spacing of the deformed Cube bands, respectively. Irrespective of annealing at 350 or 500°C, approximate N C values are estimated as 0.94 and 0.83 after 60 and 80% deformation. The apparent drop in N C after 80% deformation, in spite of the observation that more of deformed S {231}〈346〉 is found next to deformed Cube, belittles the possible role of ‘micro-growth advantage’ in determining the ‘final’ Cube recrystallization texture.

Grain morphology, texture, and microhardness gradients in aluminum diffusion-bonded to aluminum oxide

The evolution of grain morphology, crystallographic texture, and microhardness in Al bonded to Al 2O 3 is dealt with. Specimens of a bilayer Al–Al 2O 3 and symmetric trilayer Al 2O 3–Al–Al 2O 3 were produced by solid-state diffusion bonding. Metallographic examination revealed the size and shape of grains in the Al layer, and the X-ray diffraction technique was used to measure the crystallographic texture at various through-thickness and in-plane locations. The results showed the existence of gradients in grain size, grain shape, texture, and microhardness through the thickness of the Al. Away from the interface, the aluminum grains were equiaxed, with a sharp cube recrystallization texture. Near the interface elongated and slanted grains, with a rotated cube texture, were observed. The microhardness was seen to correlate with the distribution of grain size. Finite element analyses employing crystal plasticity models were carried out to simulate the polygranular flow of Al during diffusion bonding. The interface constraint imposed by the Al 2O 3 layer was found responsible for the evolution of the observed gradients in microstructure in the Al layer. The predicted grain morphology trend was also in agreement with experimental observations.

Cube recrystallization texture—experimental results and modeling

Two recent ideas for understanding and modeling the development of cube recrystallization texture in rolled and plane strain deformed aluminum and copper have been tested by experimental studies. The ideas are: (i) the concept called either ‘orientation pinning’ or ‘variant inhibition’—the inhibition of the growth of recrystallized grains by contact with regions in the deformed material with similar orientation, and (ii) the simple model, α C = N C d R/ λ C, for predicting the frequency of recrystallized cube grains based on nucleation from closely spaced deformed cube bands inherited from pre-existing cube grains. λ C is the mean spacing between deformed cube bands, d R is the thickness of the recrystallized grains, both measured in the normal direction, ND, and N C is the number of cube grains per cube band in a linear traverse in ND. Detailed experimental results by orientation imaging microscopy have confirmed the importance of orientation pinning in preventing the development of the majority deformation texture components in warm deformed aluminum since here d R > λ V, the inter-variant spacing of the rolling texture variants. In the same material cold rolled to an equivalent strain, retained rolling texture developed since, after cold rolling, d R < λ V. Direct experiments have also confirmed each of the assumptions underlying the simple cube frequency model. Comparisons between the very different texture results found using only slightly different starting materials indicate the need for more quantitative experimental and modeling studies on the role of starting microstructure, grain size, shape and texture, on the development of the deformed microstructure, particularly on cube grain stability and grain fragmentation.

Cube recrystallization texture in warm deformed aluminum: understanding and prediction

The formation of cube {100}〈001〉 recrystallization texture was studied in warm plane-strain deformed aluminum. Recrystallization cube texture intensity increased from 4 to 200 times random, as the true strain was increased from 0.92 to 3.2. The increased cube was primarily due to larger numbers of recrystallized near cube grains, as cube grains had either no or very limited size advantage over grains of other orientations. The origin of cube nucleation was found in the partial stability of existing cube grains which produced thin bands of near-cube oriented deformed material and the lower stored energy of these cube bands. A simple geometrical model is proposed for the prediction of cube recrystallization texture in plane strain deformed f.c.c. metals. The model predicts the frequency of cube recrystallized grains as: N C d R/ λ C. N C is the number of cube grains per (effective) deformed cube band, d R is the recrystallized grain thickness and λ C is the spacing between effective deformed cube bands — all measured along normal direction. N C values were, in material with a low predeformed cube grain frequency, proposed to be either 1 or 2, based on the deformed microstructure. The spacing, λ C was obtained as ( d o/ a C)(1/exp ε), where d o is the initial grain size, a C is the initial cube grain fraction and ε is the true strain. This model was found to work extremely well for λ C> d R in aluminum.

Analysis of texture and mechanical anisotropy of Al-Mg alloy sheets for autobody applications

The effect of texture on mechanical anisotropy was investigated in three commercial Al-Mg alloy sheets for autobody applications. The textures were identified using ODF (oriented distribution function) analyses of XRD pole figures. The volume fractions of existing texture components were calculated based on the Gaussian function approximation. The tensile tests were performed in different directions to the rolling direction of the sheet in order to analyze the mechanical anisotropy. The Cube and CubeND recrystallization textures were identified as dominant texture components of the Al-Mg alloy sheets. The experimental R-values were in good agreement with the prediction based on the CMTP (continuum mechanics of textured polycrystals). The mechanical anisotropy originated from CubeND texture component was weaker than that originated from Cube texture component. The anisotropy in R-value decreased with increasing the amount of random spread components and the AR value was measured as 0.01 when the random spread component was 70%. The biaxial stretchability obtained from Erichen test was enhanced with decreasing the mechanical anisotropy in Al-Mg alloy sheet.