scholarly journals Deformation Zone Geometry and Texture Gradients in Cold-Rolled Niobium

1977 ◽  
Vol 2 (3) ◽  
pp. 183-203 ◽  
Author(s):  
R. A. Vandermeer ◽  
J. B. Bernal

Several niobium plates were cold-rolled at room temperature to a total reduction of 60% maintaining the geometry of the zone of deformation constant for each plate. Pole figures were obtained by means of the Schulz x-ray reflection technique from various depths in the thickness direction for plates rolled with different ∆, the ratio of the mean height of the deformation zone to its contact length. Severe texture gradients were noted and characterized for Δ>1; a modified texture different from the normal texture was observed at intermediate through-the-thickness locations. Both lateral widening and microhardness gradients were also in evidence for this case. No previously proposed theoretical explanation could account for these results.

1990 ◽  
Vol 5 (3) ◽  
pp. 484-487 ◽  
Author(s):  
S. R. Nishitani ◽  
M. H. Oh ◽  
A. Nakamura ◽  
T. Fujiwara ◽  
M. Yamaguchi

Polysynthetically twinned crystals of TiAl with a nearly stoichiometric composition have been grown and rolled at room temperature. The maximum total reduction in thickness which is attainable without fracture depends on lamellae orientation with respect to the rolling plane and rolling direction. When specimens are oriented such that shear deformation parallel to the lamellar planes is operative during rolling and its operation causes lengthening of specimens, such specimens can be rolled up to about 50% reduction in thickness. The (111) pole figures are determined for the surface of specimens rolled to several different amounts of reduction, and the formation of surface texture is briefly discussed.


1989 ◽  
Vol 10 (2) ◽  
pp. 117-134 ◽  
Author(s):  
R. Shimizu ◽  
J. Harase ◽  
K. Ohta

In an attempt to investigate the accuracy of the vector method for crystal texture analysis, a comparison has been made between the inversion result of the pole figure made by X-ray studies using the VM and the inversion result of the pole figure made by ECP. A comparison has been made between the inversion by the pole figure generated by direct measurement of orientations by ECP and the actual orientation distribution (measured by ECP) displayed in the same mode. The materials studied were recrystallized Fe–3% Si and Fe–50% Ni. The main findings were:• In the mean intensities of each individual Box, the inversion results of pole figures made from orientations determined by ECP were in good agreement with the inversion from (100) pole figures made by X-ray or actual orientation distribution (made by ECP) displayed in the same mode as the vector method.• For Fe–3% Si, quite a good agreement was obtained between the results inverted from X-ray pole figure and the direct measurement by ECP for the intensity distribution of minor texture component along ζ angle. It was concluded from these investigations that the inversion of the pole figure by the vector method is accurate enough for most practical purposes.


2021 ◽  
pp. X
Author(s):  
Burcu ERTUĞ

Sr-hexaferrite samples were produced via the conventional ceramic method. X-ray diffractometry (XRD) patterns confirmed the single nanocrystal phase as Sr-hexaferrite where any pattern peaks of unreacted Fe2O3 phase were  not detected. The mean crystallite size values were determined to be 44.12±3.4nm and 41.2±3.2nm for SHF-O1 and SHF-O2, respectively. The chemical bonding peaks of our sample indicated that the structure of Sr-hexaferrite formation was confirmed by FTIR spectra result. Scanning electron microscopy (SEM) images indicated clearly observed porosity regions with relative densities as high as 94% and 87% for SHF-O1 and SHF-O2 samples.The vibrating sample magnetometry (VSM) of each sample at 2K and under a magnetic field of 10 kOe yielded saturation magnetizations, Ms of 93.5 and 94.1 emu/g; remanence values, Mr of 76.4 and  67.8 emu/g for SHF-O1 and SHF-O2, respectively. The magnetization loops of both samples indicated a soft ferrimagnetic behaviour in which the saturation magnetizations were higher than those measured  at room temperature in the previous studies. The coercivities, Hc were measured to be 150Oe for both samples. The squareness values, SQR (Mr/Ms) were measured to be high, approximately 0.82 and 0.72 for SHF-O1 and SHF-O2, respectively. Depending on the adequate values of magnetization and coercivity along with small mean crystallite size and low porosity values of the obtained Sr-hexaferrite samples, we estimate that these samples are likely to be evaluated further for the potential use as thermoseeds in the field of clinical hyperthermia.


Author(s):  
D. L. Rohr ◽  
S. S. Hecker

As part of an on-going study of 1100 Al at large plastic strains, we have examined cold-rolled samples from three orientations; through the sheet surface, and in the thickness direction along the rolling direction (RD) and transverse to the RD. Cell and subgrain sizes were determined in the same manner as for the earlier work.The starting plates of 1100 Al were annealed at 500 C and then rolled at room temperature to various thicknesses. These rolled plates were used to produce final samples rolled to 0.5 mm thickness with 62, 80, and 90% reductions. Thin foils were produced by lapping and jet electropolishing. A method was developed to make thin foils perpendicular to the sheet by lapping small pieces of sheet (1 mm wide) edgewise from both edges. This produces sheet 0.25 mm thick by 0.5 mm wide which were mounted between two 0.25-mm-thick 1100 Al disks 3 mm in dia. These disks had been slitted in the center to have slits ≪ 0.5 mm wide.


2013 ◽  
Vol 535-536 ◽  
pp. 211-214 ◽  
Author(s):  
Dong Nyung Lee ◽  
Heung Nam Han ◽  
Hyun Sik Choi

The texture of rolled sheets is known to vary with depth from the surface to the center due to inhomogeneous deformation, which can be caused by a characteristic deformation zone geometry and friction between materials and rolls during rolling. In order to study the deformation and recrystallization (Rex) textures of the surface layers of Al and Cu sheets cold rolled without lubrication, 5 Al sheets were stacked and rolled by 88% and 4 Cu sheets were stacked and rolled by 93% in 4 passes at room temperature. The surface layers separated from the rolled sheets were annealed for 1 h at 500 °C for Al and at 550 °C for Cu. The deformation textures of the surface layers were characterized by different shear textures, which gave rise to very different Rex textures.


Author(s):  
P.G. Caceres ◽  
R.D. Garwood

Convergent beam microdiffraction (CBD) techniques have been used to determine changes in orientation along and across subs truetural regions such as microbands, shear bands, crystallites, etc., in a heavily cold rolled Cu - 12.5% Ni alloy of high purity. The investigation is an extension of similar studies on copper and alpha brass (see eg. 1, 2 and 3).Pole figures and inverse pole figures determined by x-ray diffraction techniques have shown (see 4 and 5) that this alloy develops a copper-type deformation texture, although, more slowly than the pure metal since a substantial increase of the 422 reflection, arising from a (112) [111] end orientation, occurs only at deformations greater than 90% (ε ∼2.30).


1972 ◽  
Vol 25 (11) ◽  
pp. 2301 ◽  
Author(s):  
WJ Asker ◽  
DE Scaife ◽  
JA Watts

X-ray diffraction and halogen nuclear quadrupole resonance (n.q.r.) methods show that Rb3ZnBr5, (NH4)3ZnBr5, and CsZnI5 are isostructural with orthorhombic (NH4)3ZnCl5, and that Rb3ZnCl5 has the tetragonal Cs3CoCl5 structure. ZnI2,2NH3 is isomorphous with the corresponding chloride and bromide diammines. Rb2ZnBr4 and (NH4)2ZnBr4 have structures of Cs2ZnBr4 type, although the rubidium salt shows some stacking faults. In the complex chlorides 35Cl n.q.r. frequencies are grouped about 9 MHz, while the bromides have 81Br frequencies grouped around 60 MHz. The � → 3/2 transitions of 127I in the iodides are in the region of 76 MHz. The diammine compounds ZnBr2,2NH3 and ZnI2,2NH3 have frequencies close to the mean values for the ZnBr42- and ZnI42- ions respectively, but in the hydrates ZnCl2,l⅓H2O,ZnBr2,2H2O, β-KZnBr3,2H2O, and KZnI3,2H2O the halogen frequencies are increased. N.q.r. and X-ray data are also reported for the compound Cs3CuCl5, formed by quenching the melt. This compound slowly disproportionates at room temperature into Cs2CuCl4 and CsCl.


Author(s):  
Jan T. Bonarski ◽  
Wieslaw Olek

Investigations of the crystallograpically organized regions of mature and juvenile Scots pine wood were performed. Experimental methods of X-ray diffraction were applied. Incomplete pole figures were measured, in order to calculate the orientation distribution function. The differences in the texture of the mature and juvenile wood were determined. The traditional concept of the mean microfibril angle was enhanced by developing the misorientation parameters. Evident differences in the space arrangement of cellulose of the both zones of wood were identified and described.


2000 ◽  
Vol 33 (2) ◽  
pp. 364-371 ◽  
Author(s):  
O. V. Mishin ◽  
E. M. Lauridsen ◽  
N. C. Krieger Lassen ◽  
G. Brückner ◽  
T. Tschentscher ◽  
...  

A novel experimental technique that employs high-energy synchrotron radiation is used for the investigation of through-thickness texture gradients in two aluminium plates, cold-rolled 40% with either intermediate or small draughts. In these two plates, crystallographic textures are inspected in a large number of layers. Texture maps of pole densities throughout the sample thickness are presented. A texture of the rolling type is developed through the plate thickness after intermediate draught rolling. Pronounced inhomogeneities associated with the shear texture are observed in the sample rolled with small draughts. For selected layers, direct pole figures are compared with those obtained by traditional low-energy X-ray diffraction and by the electron backscattering pattern technique using a scanning electron microscope. A good qualitative agreement between textures measured using the three different techniques is obtained. Experimental aspects and potentials of the new technique are discussed.


2013 ◽  
Vol 753 ◽  
pp. 534-537 ◽  
Author(s):  
Yuriy Perlovich ◽  
Margarita Isaenkova ◽  
Olga Krymskaya

Data are presented on the x-ray line broadening distribution over the texture of cold-rolled Nb and Mo sheets. The method of generalized X-ray pole figures, which combine texture measurements with X-ray line profile analysis, is employed. The X-ray line broadening is considered as an indicator of residual deformation effects. It was revealed that these effects in cold-rolled BCC metals rise as the grain orientation shifts away from texture maxima towards texture minima. The intensity of X-ray reflections change during annealing at 200 – 500C and this change correlates with the line broadening. The recrystallization texture of BCC metals is dominated by orientations deflected from the peak maxima by 25 – 30 deg. These orientations in the deformed structure have relatively high stored energy. Their volume fraction is sufficient for them to be able to consume most of the deformed matrix.


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