Formation Of Annealing Texture Research Articles

Annealing textures of low stacking fault energy (SFE) FCC materials: Traversing binary to high entropy alloys (HEAs)

Although the origin of brass-type deformation texture in low SFE alloys has been extensively investigated, the annealing textures of such materials have received less attention, mostly limited to brass and different austenitic steels. On the other hand, the annealing textures of low SFE HEAs have been investigated more intensively recently; however, a comprehensive insight into annealing texture formation from HEAs down to binary systems is missing. To bridge the gap, the annealing texture of FCC single-phase Cu-11.6 at%Al alloy with SFE ∼10 mJm−2 comparable to HEAs was first investigated as a model binary system and compared with selected low SFE binary, medium entropy (MEAs), and HEAs to understand the similarities and characteristic differences. The cold-rolled alloy showed massive nanostructure and a typical brass-type texture featured by a strong B ({110}<112>) component expected for a low SFE alloy. Annealing resulted in ultrafine recrystallized microstructure but extensive grain growth at higher temperatures, like other binary alloys but unlike HEAs. The annealing texture showed the retention of deformation components, weak α-fiber (ND//<110>) components and a high random fraction. These features were very similar to HEAs/MEAs and attributed to the absence of oriented nucleation (ON) or oriented growth (OG) mechanisms. However, striking differences such as strong BR ({236}<385>) and D ({113}<332>) components in the brass alloy, selective growth of the G ({110}<001>) and G/B ({110}<115>) in binary Ni-60wt%Co alloy, and strong retention of the {110}<112> component in the annealing texture of (FCC+B2) dual-phase AlCrFe2Ni2 HEA were remarkable. These outcomes indicated underlying microstructural effects on annealing texture formation in low SFE binary to HEAs/MEAs and should motivate further research.

Grain boundary co-segregation in magnesium alloys with multiple substitutional elements

Alloying additions in magnesium can modify common basal textures during recrystallization based on their solid solubility and precipitation behavior. With a variety of tenable theories in the literature, a far greater understanding is required of how restricted growth due to drag effects and annealing texture formation are linked. In the current work, a complex magnesium alloy Mg-3Al-1Zn-0.3Ca (wt.%) with multiple substitutional elements was subjected to a combination of deformation and annealing treatments in order to examine how a variation of bulk solute concentrations would influence its segregation and precipitation behavior. The work focuses in particular on solute segregation to grain boundaries and demonstrates that the type and level of segregation play a key role in controlling the growth behavior in such a way that restricts preferential growth of grains with a basal texture. Deeper knowledge in this area can be expected to advance current alloy design strategies by tweaking the solute concentration in the solid solution through targeted heat treatments to result in the required amounts of second phase precipitation and grain boundary segregation.

Influence of Cold Rolling Reduction and Cross Rolling on Recrystallization Texture Formation in Electro Deposited Pure Iron with a Sharp and Homogeneous &amp;lt;111&amp;gt;//ND Fiber

The cold rolling and annealing texture formation has been investigated in electro deposited pure iron which has an extremely sharp and isotropic &lt;111&gt;//ND fiber. Regardless of cold rolling reduction, {111}&lt;112&gt; intensified texture is formed after cold rolling. Similar texture remains after recrystallization in 65% cold rolled material while {111}&lt;110&gt; type texture forms in 80% and 90% cold rolled ones. The recrystallized grains at the stage of 5% recrystallization have {111}&lt;112&gt; orientation in 65% cold rolled sheet, whereas {111}&lt;110&gt; is observed in 80% cold rolled one. From this aspect, it is considered that the nucleation orientation plays an important role in the recrystallization texture formation. In the meanwhile, the growth of the recrystallized nuclei is also supposed to affect the recrystallization texture formation. The nuclei with {111}&lt;112&gt; orientation in lightly cold rolled sheet are easier to consume the deformed matrix than they do in heavily cold rolled sheets because their frequency to encounter a deformed grain with nearly the same orientation is much smaller in lightly cold rolled specimen, which can result in a large mobility for growth. Cross cold rolling makes cold rolling texture rather homogeneous &lt;111&gt;//ND fiber, which gives rise to an almost homogeneous &lt;111&gt;//ND fiber after annealing.

Influences of Mn on Recrystallization Behavior and Annealing Texture Formation in Ultralow-carbon and Low-carbon Steels.

The influences of Mn of the recrystallization behavior and the formation of recrystallization texture in Ti-added ultralow-C steels were investigated and compared with that of low-C Al-killed steels. In Ti-added ultralow-C steels, Mn does not influence the recovery, the nucleation and growth rate of recrystallization, or the recrystallization. On the other hand, in low-C Al-killed steel, Mn inhibits the recovery and retards the growth rate of recrystallized grains. Consequently, the development of ND// is impaired, and the intensity of ND// increases after recrystallization. The differences in recrystallization behavior and annealing texture formation between the two kinds of steel were discussed from the viewpoint of the roles of precipitates and solute Mn. It was determined that Mn-C complex is the main reason for these differences.

Role of shear bands in annealing texture formation in 3%Si-Fe(111)[112] single crystals.

The nature of heterogeneous deformation bands and the mechanism of Goss texture formation have been studied in the process of cold rolling and annealing of 3%Si–Fe (111)[112] single crystals. After cold rolling, two kinds of shear bands are observed. Wide shear bands (type I) make an angle of 35° to the rolling direction in longitudinal section, whereas narrow shear bands (type II) have an angle of 17° Rotations of crystallite orientations within the shear bands occur in the direction predicted by theory, however, the angles of the bands cannot be satisfactorily rationalised at present. The fine recrysallized grains nucleated along shear bands of type I have preferentially Goss orientation with a small dispersion (±10°) along TD//[110], whereas those nucleated within the type II bands have approximately twice as large an orientation spread. Following the nucleation along shear bands, recrystallization takes place by growth into the surrounding matrix.

Effect of heat treatments prior to cold rolling on recrystallization texture in low-carbon titanium-added sheet steel.

The processes of recrystallization and annealing-texture formation in rapid heating and isothermal annealing have been observed in cold rolled sheets of a low-carbon titanium-added steel which were subjected to three types of heat treatments prior to cold rolling: quenching from 1250°C (Q0) and the subsequent annealing for 0.5hr (Q0.5) or 100 hr (Q100) at 700°C. In the 850°C-recrystallization, the relative intensity of (111) reflection was lower, while that of (110) reflection was higher, in specimen Q0 than in specimens Q0.5 or Q100. On the other hand, in the same specimen (Q0) annealed in two stages, the 1st at 700°C and the 2ndstage at 850°C, the {111} recrystallization texture developed markedly. In the early stage of annealing of the specimen Q0 the recovery was suppressed probably by the effects of interaction of titanium or Ti-C dipoles with dislocations. From the thermoelectric power vs, conductivity diagram and the transmission electron micrographs, the amount of recovery before commencement of recrystallization was estimated to be larger in specimen Q100 than in specimen Q0. In addition to the changes of deformation structure and texture that arise from the scavenging of interstitial solute atoms, the increased amount of recovery before nucleation of recrystallized grains was pointed out as one of the important factors which develop the recrystallization texture characteristic to the low-carbon titanium-added sheet steels.

Effects of the size and morphology of cementite particles on the annealing texture in low-carbon aluminium-killed steel.

The processes of cementite dissolution, recrystallization and annealing-texture formation during isothermal annealing have been observed in cold-rolled sheets of a low-carbon aluminium-killed steel in which the effect of the pre-precipitation clusters of aluminium-nitride was eliminated by preliminary heat-treatments. Inhibition of nucleation due to pinning of dislocations by dissolved carbon atoms and inhibition of the growth of recrystallized grains by carbon atoms or by fine cementite particles have been considered as probable effects which decrease the rate of recrystallization. The predictions were, however, found to be inconsistent with the experimental results obtained. It was supposed that different annealing textures were produced through changes in the size and distribution of constrained-deformation regions in the deformed iron matrix. When the cementite particles were coarse and widely spaced, an annealing texture with strong {222} and weak {110} orientations was obtained by rapid heating directly to a high temperature. In a case when the hot band contained fine spheroidal cementite particles, a similar annealing texture could be obtained by two-stage annealing. The presence of pearlite had a deteriorating effect on the development of the favourable texture.