Stress-Induced Lattice Transit Behavior in a Cold-Rolled Cu-Al-Mn Two-Way Shape Memory Alloy

2007 ◽  
Vol 561-565 ◽  
pp. 1445-1449
Author(s):  
Ji Jie Wang ◽  
B.L. Wu ◽  
Z.W. Huang ◽  
Tong Cui ◽  
Yan Dong Wang ◽  
...  

The effect of cold rolling on two-way shape memory was investigated by x-ray diffraction technique and TEM in a Cu-18Al-10.5Mn (at.%) alloy. Cold rolling leads to a preferred orientation distribution on the stress-induced martensite with 6M-structure, which leads to the dependence of two-way shape memory on the specimen directions. The relationship of stress state and anisotropy of 6M-structured martensite lattice inside cold rolling deforming region is elucidated through analyzing the deformation process-related variant selection according to original grain orientation.

1985 ◽  
Vol 49 (350) ◽  
pp. 81-85 ◽  
Author(s):  
T. Sameshima ◽  
G. S. Henderson ◽  
P. M. Black ◽  
K. A. Rodgers

AbstractVivianite specimens from various world localities yield X-ray powder patterns of two types: one corresponds with that shown by synthetic Fe3(PO4)2· 8H2O and is not readily distinguished from that of barićite; the second shows reflections of monoclinic vivianite and triclinic metavivianite along with reflections of a bobierrite-type phase. The triclinic phase occurs as two twin-related lattices with twin plane 110 being the structural equivalent of 010 in the monoclinic phase. The relationship of the bobierrite-type lattice to the other two has not been established. The ternary pattern is produced by some coarse-grained vivianites on natural oxidation. Finer grained vivianites oxidise to an X-ray amorphous state without passing through a triclinic intermediate.


1957 ◽  
Vol 1 ◽  
pp. 73-99 ◽  
Author(s):  
F. Schossberger

AbstractA comprehensive chart is preserit of the X-ray diffraction effects of gas-and Uquid-like armorphous substances, small particle-size materials, mixtures of amorphous and crystalline compounds, sheetlike crystals, and fibrous materials.The relationship between the X-ray diagrams and chemical preparations as shown by typical examples from the field of the manufacture of active catalysts cadmium sulfide semiconductors, pour point-depressed lubricants, electroless nickel platings and metal-filled cellulose fibers.The investigation of thin surface layers formed by chemical reactions required the combination of electron and X-ray diffraction techniques. The usefulness of this combination of methods is demonstrated by a study of black stain formation on cold rolled annealed steel. By identifying the materials in the stain and determining the sequence in which they formed a reaction mechanism between steel surface and annealing-gas can be postulated.


2007 ◽  
Vol 546-549 ◽  
pp. 2097-2102
Author(s):  
Ting Luo ◽  
Yi Zhang ◽  
Qing Rong Feng

The relationship of the resistivity versus synthesizing temperature of sol-gel YBa2Cu3O7-x samples, with Tc 91K, was studied while synthesizing in flowing oxygen atmosphere. A set of high temperature -T curves were obtained for the whole process. After four rounds of synthesizing, the resistivity of the sample was =1.00×10-3cm at room temperature. The -T curve of the last round also showed that the orthorhombic to tetragonal phase transformation of the sample occurred around 600oC that is lower than the YBa2Cu3O7-x sample prepared in ambient atmosphere. Other measurements such as X-ray diffraction, SEM measurement, low temperature R-T and M-T measurement were also taken to get more information of these samples.


2020 ◽  
Vol 56 (1) ◽  
pp. 89-97
Author(s):  
I. Angela ◽  
I. Basori ◽  
B.T. Sofyan

Al-brass alloys (Cu29.5Zn2.5Al wt. %) were produced by gravity casting and homogenized at 800?C for 2 h, resulting in a binary phase morphology identified as cubic ? and martensitic ?? phases through X-ray diffraction (XRD). Samples were then subsequently cold rolled and annealed at 150, 300, 400, and 600?C for 30 minutes. Visible traces of slip, intersecting slip bands, and shear bands were observed in microstructure images of the samples after each progressive deformation stage. Deformation-induced martensites were present after 20 % cold rolling. Higher thickness reduction resulted in simultaneous strain hardening of the phases. Low temperature annealing slightly increased microhardness, of both ? and ??, due to the formation of precipitates. SEM-EDX analysis showed that no solute segregation was found in annealed samples. Annealing at higher temperature resulted in conventional softening. Recrystallized equiaxed ?? phase grains were visible after annealing at 600?C.


2016 ◽  
Vol 69 (4) ◽  
pp. 372 ◽  
Author(s):  
Shi-Qiang Bai ◽  
Lu Jiang ◽  
David James Young ◽  
T. S. Andy Hor

Two new dinuclear CuII complexes [Cu2Cl4(L1)2] (1) and [Cu2Cl4(L2)2] (2) (L1 = 2-((4-(2-(cyclopentylthio)ethyl)-1H-1,2,3-triazol-1-yl)methyl)pyridine; L2 = 2-((4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl)methyl)benzonitrile) were synthesised and characterised by single-crystal X-ray diffraction (XRD), powder XRD, thermogravimetric analysis, elemental analysis and IR measurements. The picolyl-triazole ligand L1 coordinates in a chelate-bridging mode forming a dinuclear structure 1. The more rigid pyridyl-triazole ligand L2 chelates only, generating a chloride-bridged dinuclear complex 2. Both crystals of complexes 1 and 2 show dominant plate shapes that correlate with weak 2D H-bonding interactions in the lattice. A mononuclear structure (3, [CuCl2(L3)2]⋅6H2O, L3 = 3-((4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl)methyl)benzonitrile) yields block shape crystals that correlate with 3D H-bonding interactions. This study demonstrates tunable assembly at the molecular level and the relationship of crystal shape with weak lattice interactions.


2011 ◽  
Vol 702-703 ◽  
pp. 647-650
Author(s):  
Ahmed A. Saleh ◽  
Elena V. Pereloma ◽  
Azdiar A. Gazder

A TWinning Induced Plasticity (TWIP) steel was cold rolled to 42% thickness reduction followed by isochronal annealing for 300 s between 600-850 °C. Bulk texture evolution during recrystallisation was investigated by X-Ray Diffraction. While the development of the α-fibre after cold rolling is typical of low stacking fault energy materials, anomalously higher intensities were noted for the Goss ({110}) compared to Brass ({110}) orientations. Upon recrystallisation, the main rolling texture components were retained and ascribed to nucleation at orientations close to those of the deformed matrix followed by annealing twinning which leads to crystallographically identical variants. Unlike previous texture investigations on austenitic steels, the relatively homogeneous deformation microstructure and uniform distribution of subsequent nucleation sites led to the retention of the F ({111}) orientation. Moreover, the firsthand observation of the Rotated Copper ({112}) orientation in TWIP steel is attributed to the second order twinning of the A ({110}) orientation.


1977 ◽  
Vol 41 (318) ◽  
pp. 287-287 ◽  
Author(s):  
Mike J. Pearson

SynopsisA phosphate-rich carbonate nodule from carboniferous mudstones has been studied by wet chemistry, X-ray diffraction, and electron microprobe. Partial heavy-liquid separation has enabled characterization of the phosphate phase as francolite (carbonate fluorapatite) with a composition Ca10(PO4)5·59(CO3)1·00((OH)1·49F2·10). Diffractometer data for this mineral is presented and cell dimensions are calculated as a = 9·349 Å, c = 6·887 Å. with c/a = 0·737. The problem of the structural positioning of carbon in francolite is discussed.The francolite is seen in thin section as a structureless groundmass enclosing siderite spheru-lites. Electron microprobe X-ray distribution photographs for P, Al, Si, Mg, and Fe show the relationship of these two phases to quartz, pyrite, and at least two clay minerals. One of the latter is intimately mixed with francolite.Possible origins of phosphatic nodules are discussed. Textural evidence in the present case strongly suggests that the francolite is concretionary and formed during early diagenesis possibly by replacement of earlier calcite. Phosphate was probably derived from protein degradation, which also maintained the alkaline pH necessary for francolite formation.


2015 ◽  
Vol 60 (3) ◽  
pp. 1789-1794 ◽  
Author(s):  
J. Kowalska ◽  
W. Ratuszek ◽  
M. Witkowska ◽  
A. Zielińska-Lipiec ◽  
M. Kowalski

Abstract Fe–23wt.%Mn–3wt.%Si–3wt.%Al alloy was cast, homogenized at 1150ºC, hot-rolled at temperatures between 1200ºC and 900ºC and next cold-rolled from 5% up to 40% reductions in thickness. Microstructure and texture of this alloy, which has a low stacking fault energy, were defined after cold-rolling. Investigation of transmission electron microscopy and X-ray diffraction showed that mechanical twinning and martensitic transformations (γfcc→εhcp and γfcc→εhcp→α′bcc) took place during cold-rolling. The crystallographic Shoji-Nishiyama (S-N) {00.2}ε║{111}γ, <11.0>ε ║ <110>γ and Kurdjumov-Sachs (K-S) {111}γ║{101}α’, <101>γ║<111>α’ relations between martensite (ε, α’) and austenite (γ), were found in the coldrolled material.


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