Main Texture Components Research Articles

VPSC-TDT modeling and texture characterization of the deformation of a Mg-3Al-1Zn plate

Abstract Wrought magnesium and Mg alloys are characterized by a strong basal texture and several slip and twin modes activated during plastic deformation. A hot rolled AZ31 plate was deformed in tension and compression along 4 directions at room temperature, and texture was investigated after e = 0.1 plastic strain by EBSD. The plastic deformation and deformed texture were simulated with the visco-plastic self-consistent twinning-detwinning model (VPSC-TDT), and compared with the experimental observations. {10–12} extension twins are responsible of the main texture variations, but {10–11} contraction and {10–11}{10–12} double twins were also observed in the 8 samples. The simulated main texture components are in good agreement with the measurements. Because the TDT scheme in its present form does not allows secondary twinning, some minor differences between the predicted and observed textures are observed. The strain anisotropy ( r -value) was over-estimated in in-plane tension, suggesting a very low threshold stress for basal slip.

The influence of deformation texture on nucleation and growth of cube grains during primary recrystallization of AA1050 alloy

The influences of microstructure and texture on the early stages of recrystallization of a commercial AA1050 alloy have been characterized with particular attention to cube grain formation. Samples were deformed along two deformation modes to form different as-deformed texture components and then lightly annealed: one group was plane strain compressed (PSC) in a channel-die, whereas the second group was deformed by equal channel angular extrusion (ECAE). The textures were measured by X-ray diffraction and SEM/EBSD. After both deformation modes a very weak residual cube texture component was observed in the samples. Cube-oriented grains were not formed during annealing of the ECAE samples whose main as-deformed texture components were close to {124}<651>. During recrystallization these transformed to two components of ∼{100}<011> and ∼{221}<114>-type essentially by <110> rotations. Cube grains were extensively formed only during annealing of PSC samples. They were situated preferentially inside or in between the S-oriented deformed areas with local misorientations about <111> axes.

Spatial variation of microtexture in linear friction welded Ti-6Al-4V

The variation of microstructure and microtexture across a Ti-6Al-4V (Ti64) linear friction weld was investigated using scanning electron microscopy (SEM) and electron backscattered diffraction (EBSD). Pole figures and misorientations distribution obtained from α phase show four distinct regions within the weld, with different textural characteristics. Nevertheless, the main texture components remain the same in centre weld zone and thermal mechanical affected zone with the basal poles of the α phases located at around 0°, 60° and 90° to the sample normal (Z0) direction. The results indicate that the texture components are strongly related to the amount of transformed β phase. The deformation of the primary α grains has a limited effect on the texture development.

Annealing behavior of a 304L stainless steel processed by large strain cold and warm rolling

A 304L-type austenitic stainless steel was subjected to plate rolling at ambient temperature and at 573K to total strains of 3 and then annealed at temperatures of 873, 973 and 1073K. The structural changes during annealing were associated with the austenite reversal (for the cold rolled samples), recrystallization and grain growth, which depended significantly on the annealing temperature. The grain growth exponent of 4 and 5 was obtained after annealing at 973K/1073K for the cold and warm rolled samples, whereas very sluggish grain coarsening took place at 873K. The texture evolution during annealing in the austenite domain was characterized by gradual weakness of cold/warm rolled textures, although the main texture components such as Brass, {110}<112>, and S, {123}<634>, remained in the annealed samples irrespective of annealing mechanisms of microstructure evolution. The grain coarsening during annealing was accompanied by gradual softening. The yield strength of ultrafine grained steel processed by cold/warm rolling followed by annealing could be expressed by a Hall-Petch type relationship with σ0=160MPa and ky=470MPam0.5.

Microstructure and Texture Evolution in Cladded Al 3003 Aluminum Sheets

In the present research, the texture variation during cold rolling of cladded 3003 type aluminium sheets was examined by means of X-ray diffraction. The aluminum sheets were formed in a series of 14 rolling steps, after which texture examinations were performed on both cladded and base material sides of the sheets. After certain rolling steps, the texture was also examined by removing layers from the sheets by electropolishing to reveal the texture distribution along depth. The texture was characterised through the calculation of volume fractions of the main rolled texture components. Local drawbacks were found in the texture versus thickness reduction function. The texture was found to be higher in the middle of the sheets than at the surface.

Effect of Large Strain on Texture Formation Behavior of AZ80 Magnesium Alloy during High Temperature Deformation

In previous study, the formation behavior of texture and microstructure in AZ80 magnesium alloy under high temperature deformation was investigated. It was found that the basal texture was formed at stress of more than 15-20MPa and the non-basal texture was formed at stress of less than 15-20MPa. This means that stress of 15-20MPa is the change point of deformation mechanism. Therefore, in this study, uniaxial compression deformation of AZ80 magnesium alloy was carried out at high temperature deformation (stress of 15-20MPa). Behaviors of microstructure and texture development are experimentally studied. The material used in this study is a commercial magnesium alloy extruded AZ80. The uniaxial compression deformation is performed at temperature of 723K and strain rate 3.0×10-3s-1, with a strain range of between-0.4 and-1.3. Texture measurement was carried out on the compression planes by the Schulz reflection method using nickel filtered Cu Kα radiation. EBSD measurement was also conducted in order to observe spatial distribution of orientation. As a result of high temperature deformation, the maximum value of the flow stress is observed at the true stress-strain curves, and the main component of texture and the accumulation of pole density vary depending on deformation condition.

Texture formation behaviors of Mg-9Al-1Zn alloy during high-temperature compression deformation

The formation behavior of basal texture during high temperature deformation of AZ91 magnesium alloys in single phase was investigated by plane strain compression deformation. Three kinds of specimens with different initial textures were machined out from a rolled plate having a texture. The plane strain compression tests were conducted at a temperature of 723 K and a strain of 5.0 × 10-2s-1, with a strain range between -0.4 and -1.0. After deformation, the specimens were immediately quenched in oil. Before deformation, specimen A, {0001} was distributed at the center of pole figure; specimen B shows {0001} was distributed at TD direction; and specimen C, {0001} was distributed at RD direction. Texture evaluation was conducted by Schulz reflection method using nickel-filtered Cu Ka radiation and EBSD. It was found that the main component of texture and the accumulation of pole density vary depending on the deformation condition and the initial texture in all types of specimens. The crystal orientation components in this study were formed by continuous deformation and discontinuous deformation, also when (0001) existed before deformation, an extremely sharp (0001) (compression plane) texture was formed.

EBSD Study on Grain Boundary and Microtexture Evolutions During Friction Stir Processing of A413 Cast Aluminum Alloy

The as-cast Al alloys contain heterogeneous distributions of non-deforming particles due to non-equilibrium solidification effects. Therefore, these alloys have poor tribological and mechanical behaviors. It is well known that using friction stir processing (FSP), very fine microstructure is created in the as-cast Al alloys, while their wear resistance can be improved. In this research work, FSP is used to locally refine a surface layer of the coarse as-cast microstructure of cast A413 Al alloy. The main objective of this study is to investigate the effect of FSP on microstructure and microtexture evolutions in A413 cast Al alloy. The grain boundary character distribution, grain structure, and microtexture evolutions in as-cast and friction stir processed A413 Al alloy are analyzed by electron back scatter diffraction technique. It is found that with the FSP, the fraction of low ∑boundary such as ∑3, 7, and 9 are increased. The obtained results show that there are no deformation texture components in the structure of friction stir processed samples. However, some of the main recrystallization texture components such as BR and cubeND are formed during FSP which indicate the occurrence of dynamic recrystallization phenomenon due to the severe plastic deformation induced by the rotation of tool.

Changes of structure and crystallographic texture of cladding tubes from austenitic steel under thermal creep testing

The process of changes in structure and crystallographic texture of cladding tubes from austenitic steel ChS68 under thermal creep testing were studied. Testing of tubes was conducted at the temperature 700 oC in the air by their stretching in axial direction under the stress 160 MPa until rupture. By data of phase and texture analysis a number of processes, accompanying plastic deformation of tubes during thermal creep tests at elevated temperature, were identified. The main texture components of original tube, as well as texture components of different parts of the tested tube are {110}<001> and {112}<111̄>. In the rupture zone the component of the texture of tension with axis <111> along the tube axis becomes stronger. This effect is connected with activation of dislocation slip in the deformed area of tested tube near the new-formed neck. At the same time the character of texture changes in the zone of tube rupture indicates to development of the dynamic recrystallization, conditioned by the total influence of all factors, which control the passage in the tube of thermal creep. In addition, it was revealed the activation of martensitic transformations in the zone of maximal deformation of tube as a result of its creep tests.

Effect of Tempering and Strain on Decomposition of Metastable Austenite in X210CrW12 Thixo-Cast Steel

Thixoforming of hot rolled X210CrW12tool steel led to the formation of globular austenitic grains (82.4 vol.%) surrounded by eutectic mixture (α-Fe and M7C3 carbides). The thixo-cast steel reached compression strength 4.8 GPa at plastic strain 34%. The analysis of pole figures after deformation indicated distinct texturization of microstructure in comparison with undeformed steel. Main texture components for austenite were {101}, 〈010〉, while ferrite did not reveal clearly formed orientation. DSC analysis confirmed that austenitic structure in the X210CrW12 steel was metastable and temperature of decomposition depended on the strain applied at 634 °C for the un-deformed sample and at 599 °C for sample compressed up to 4.8 GPa. Discontinuous transformation of austenite into perlite, that started mainly at grain boundaries and proceeded to the center, was the predominant mechanism responsible for the decomposition of globular grains in thixoformed X210CrW12 steel. The decomposition caused by tempering of supersaturated and severely strained steel led to obtaining characteristic product of transformation of higher hardness in comparison with only tempered sample. In the deformed sample the reaction started on slip bands and twins which revealed high density of defects, promoting precipitation of carbides, followed by local depletion in carbon as a result of α′- Fe formation. In contrast to non-deformed state they covered the area of grains. Two fronts of reaction α-Fe plate +M3C → mixture of α-Fe and M7C3 carbides were also observed.

Semi-quantitative evaluation of texture components and fatigue properties in 2524 T3 aluminum alloy sheets

Effect of main texture components (Cube, Goss and Brass) on the fatigue property of 2524 T3 (Al–Cu–Mg) aluminum alloy sheet was investigated by means of X-Ray diffraction, electron back scattering diffraction, scanning electron microscopy, transmission electron microscopy and fatigue tests. A new kind of factors, which was based on the intensity ratio of texture components, were firstly defined to evaluate and discuss the relationship between texture components and the fatigue crack growth (FCG) rate semi-quantitatively. The results showed that the rate of FCG in the stable stage (II) decreased with an increase of the factor FCGB (the intensity ratio of Cube to Brass texture) obviously. When the new factor FCGB, FCG (the intensity ratio of Cube to Goss texture), and FGB (the intensity ratio of Goss to Brass texture) all exceeded than 1, as well as FCG was close to FGB, the 2524 T3 sheet exhibited the lowest fatigue crack growth rate (ΔK=33MPam1/2, da/dN<2.0×10−3). The Schmid factor and misorientation of grains boundaries would be responsible for such influence on the fatigue property.

Study of the laws of texture formation in the alloy 8011 during cold rolling and annealing

The texture evolution in grade-8011 aluminum alloy has been investigated during cold rolling and intermediate annealing. The main textural components of a hot-rolled blank have been determined using X-ray diffraction analysis and their evolution during subsequent cold rolling and intermediate annealing has been studied. The effects of the textural components on the dimensions and the arrangement of ears have been estimated at every step of producing a cold-rolled strip.

Processing of NiTi shape memory sheets – Microstructural heterogeneity and evolution of texture

In the present paper we study the evolution of microstructure and texture during processing of Ni51Ti49 shape memory sheets using electron backscatter diffraction. Hot rolling results in a heterogeneous microstructure which reflects a temperature gradient in the sheet. Equiaxed and randomly oriented grains are observed close to the surface of the hot rolled sheet while the sheet interior shows a strong texture containing two main texture components {111}<110> and {110}<110> with grains elongated along the rolling direction. In contrast, cold rolling in combination with a recrystallization heat treatment produces a more homogeneous microstructure in terms of grain morphology and grain size. It also promotes a random grain orientation along the rolling and transverse directions while the normal direction shows a strong γ-fiber {111}<uvw> texture. To get a better understanding of the elementary deformation mechanisms which control the texture evolution during rolling, textures assessed in the present study are compared with simulations reported in the literature.

Comparison of 15Cr-15Ni Austenitic Steel Cladding Tubes Obtained by HPTR Cold Pilgering or by Cold Drawing

Due to their high void swelling resistance, work-hardened titanium stabilized austenitic steels have been chosen as cladding material for sodium cooled fast reactor. In this study, HPTR cold pilgering process is compared to cold drawing at the last shaping step of the tube processing. The effects of the cold work accumulation and heat treatments are studied in connection with the microstructure (grain size), the hardness and the texture. The following results were found:- As larger amount of cold work can be applied by HPTR cold pilgering, a lower number of intermediate heat treatments are required. In addition, the bending of the tube is significantly reduced after each pass for this process allowing for a limitation of the straightening operations.- For both processes, optical micrographs show micrometric titanium carbide precipitates and the presence of deformation twins on a few grains on the final tube. A significant grain size refinement from ≈45 μm to ≈17 μm can be obtained by reducing annealing temperature from 1403K down to 1353K. For the latter, the precipitated mass fraction measured by selective dissolution of the alloy matrix is the largest, revealing a possible negative impact on swelling under irradiation.- Through-wall Vickers hardness profiles show an increase of the hardness at the outer diameter for HPTR cold pilgering whereas the hardness profile remains continuous for cold drawing. It is found that the Q-factor has an influence on these wall-thickness hardness profiles.- For each process, neutron diffraction measurements on finished tubes reveal two main fiber texture components 〈111〉 and 〈100〉 parallel to the tube axis with differences in their relative intensities.

Effect of rolling geometry on the mechanical properties, microstructure and recrystallization texture of Al-Mg-Si alloys

The effect of rolling geometry on mechanical properties, microstructure, and recrystallization texture of Al-Mg-Si alloys was studied by means of tensile tests, microstructural observations, and electron backscatter diffraction measurements. The results reveal that the elongation and the average plasticity strain ratio (r) values of the T4P (pre-aging plus natural aging)-treated alloy sheet with a rolling geometry value between 1 and 3 are somewhat higher than those of the T4P-treated sheet with a rolling geometry value between 3 and 6. The deformation and recrystallization microstructures of the sheet with a rolling geometry value between 1 and 3 are more uniform than those of the sheet with a rolling geometry value between 3 and 6. The former also possesses somewhat higher surface quality. H {001}〈110〉 and Goss {110}〈001〉 orientations are the main recrystallization texture components for the former case, whereas the latter case only includes H{001}〈110〉 orientation. Texture gradients are present in the two alloy sheets. Shear texture component F on the surface of the sheet with a rolling geometry value between 3 and 6 and its higher texture gradients have revealed that non-uniform deformation occurred during cold rolling. The effects of texture on the yield strength and r value were also discussed.

The deformation texture of rolled ribbons of copper-based alloys as a condition of producing a sharp cubic texture upon recrystallization

It has been shown that a specific quantitative relationship of main textural components after cold deformation (by rolling to 98.6–99%) of copper alloys determines the possibility of producing a sharp cubic texture in the ribbons after subsequent recrystallization annealing. The binary alloys of copper with nickel (up to 40 at %) and of copper with additions of iron and chromium correspond to this criterion. It has been found that the optimum deformation texture can be created in some ternary copper-nickel alloys with addition of Cr, Fe or Mn. It has been shown that the analysis of the component composition of deformation textures using the orientation distribution function can yield more precise predictions than the stacking fault energy values, as well as make it possible to obtain a cubic texture upon subsequent recrystallization.

Assessment of crystal plasticity finite element simulations of the hot deformation of metals from local strain and orientation measurements

Simulations of the deformation of microstructures at high homologous temperatures have been carried out using a Crystal Plasticity Finite Element (CPFE) model to predict texture and grain structure deformation in Face-Centred-Cubic (FCC) metals deformed under conditions representative of hot forming operations. Results show that the model can quantitatively predict the location and intensity of the main deformation texture components of a AA5052 aluminium alloy deformed at 300 °C under Plane Strain Compression (PSC). Simulations also reasonably predict the range of strain values measured using microgrids in the microstructure of a Fe-30wt%Ni alloy deformed at 1000 °C using a new experimental procedure. However, the model fails to reproduce accurately intra-granular strain distribution patterns. Results at room temperature, after a tensile test carried out inside a Scanning Electron Microscope (SEM) on the same model alloy, show a much closer match between simulation and experimental results. Despite discrepancies for some local deformation features, the model predicts the formation of intense deformation bands running at 45° with respect to the tensile axis and located along the same grain boundaries as in the experiment. Results, therefore, highlight the limitations of deterministic CPFE simulations for situations where the grain size to sample thickness ratio is small and for which the sub-surface grain geometry strongly affects surface strains. They also show that reliable predictions of the statistical response of a polycrystalline aggregate can be obtained for the hot deformation of metals which controls microstructure evolution during the processing of metals.

Texture Formation Behaviors in AZ80 Magnesium Alloy during High-Temperature Plane Strain Compression

The behavior of texture formation during high-temperature deformation in AZ80 magnesium alloy is investigated. Three kinds of specimens were machined out from rolled plates. The plane strain compression tests were conducted at various deformation conditions – temperature, strain and strain rate. After compression deformation, texture measurement was carried out on the mid-plane section parallel to the compression direction by the Schulz reflection method and EBSD measurement. The maximum values of the flow stress are observed in all the cases at the true stress – true strain curve for three type of specimens. It is found that the main component of texture and the accumulation of pole density vary depending on deformation condition and initial texture. Six kinds of crystal orientation components have been observed after deformation in total. (0001)&lt;10-10&gt; is formed regardless of the initial texture.

Influence of thermomechanical processing on microstructure, texture evolution and mechanical properties of Al–Mg–Si–Cu alloy sheets

Influence of thermomechanical processing on the microstructure, texture evolution and mechanical properties of Al–Mg–Si–Cu alloy sheets was studied systematically. The quite weak mechanical properties anisotropy was obtained in the alloy sheet through thermomechanical processing optimizing. The highly elongated microstructure is the main structure for the hot or cold-rolled alloy sheets. H {001}〈110〉 and E {111}〈110〉 are the main texture components in the surface layer of hot-rolled sheet, while β-fibre is dominant in quarter and center layers. Compared with the hot-rolled sheet, the intensities of β-fibre components are higher after the first cold rolling, but H {001}〈110〉 component in the surface layer decreases greatly. Almost no deformation texture can be observed after intermediate annealing. And β-fibre becomes the main texture again after the final cold rolling. With the reduction of the thickness, the through-thickness texture gradients become much weaker. The through-thickness recrystallization texture in the solution treated sample only has cubeND {001}〈310〉 component. The relationship among thermomechanical processing, microstructure, texture and mechanical properties was analyzed.

Recrystallization Texture Transition in Fe-2.1 Wt Pct Si Steel by Different Cold Rolling Reduction

The competition dependent on cold rolling reduction among main recrystallization texture components in Fe-2.1 wt pct Si sheets was investigated from the hot band characterized by strong Cube ({001}〈100〉) at center layer and weak Goss ({110}〈001〉) at quarter layer. The deformation and recrystallization textures through thickness were both analyzed by X-ray diffraction technique. Goss, Cube, and {111}〈112〉 components dominate the recrystallization texture in sequence with the cold rolling reduction increasing from 60 to 90 pct. This recrystallization texture transition with cold rolling reduction can be explained in terms of the number and nature of nucleation sites for various texture components. A variety of final recrystallization textures are proposed for non-oriented silicon steel by designing texture and microstructure of hot band and cold rolling reduction.