The NaAlSiO4 nepheline-carnegieite solid-state transformation

1994 ◽  
Vol 209 (2) ◽  
Author(s):  
H. Schneider ◽  
O. W. Flörke ◽  
R. Stoeck
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Single Crystals ◽  
Transformation Process ◽  
State Transformation ◽  
Solid State Transformation ◽  
X Ray ◽  
Thermally Activated ◽  
Transformation Mechanisms ◽  
Temperature Transformation

AbstractThe reconstructive high-temperature transformation of NaAlSiOX-ray precession patterns of single crystals heattreated between 1543 K and 1593 K yielded an oriented transformation of NaAlSiOThe oriental relationships between nepheline and carnegieite are similar to those observed in the high-temperature transformation of tridymite to cristobalite. However, the transformation mechanisms are believed to be different. Thermally activated Na and weakening of the tetrahedral Al–O-bonds produce quickly migrating non-bridging O-atoms which act as conversion nuclei, accelerating strongly the transformation process in comparison to SiO

scholarly journals Maskelynite formation via solid-state transformation: Evidence of infrared and X-ray anisotropy

2015 ◽  
Vol 120 (3) ◽  
pp. 570-587 ◽  
Author(s):  
Steven J. Jaret ◽  
William R. Woerner ◽  
Brian L. Phillips ◽  
Lars Ehm ◽  
Hanna Nekvasil ◽  
...  
Keyword(s):  
Solid State ◽  
State Transformation ◽  
Solid State Transformation ◽  
X Ray

The Effects of Cooling Rate Upon Xdt m TiAl Weld Microstructure

1990 ◽  
Vol 194 ◽  
Author(s):  
Erica Robertson ◽  
Mary Ann Hill ◽  
Ricardo B. Schwarz
Keyword(s):  
Solid State ◽  
Cooling Rate ◽  
Volume Fraction ◽  
Mechanical Test ◽  
Test System ◽  
X Ray Diffraction ◽  
State Transformation ◽  
Solid State Transformation ◽  
X Ray ◽  
Weld Microstructure

AbstractFusion zone microstructures of an electron beam (EB) welded XDt m Ti–48at%Al + 6.5 vol% TiB2 alloy revealed plate-like precipitates which were absent in the base metal. The volume fraction of this phase increased with increasing cooling rate and correlated with increased weld cracking frequency. To determine whether this phase was a product of solidification from the melt or a product of a solid-state transformation, the microstructures of the welds were compared to those of samples cycled in a Gleeble 1500/20 Thermal-Mechanical Test System which was programmed to simulate the solid-state portion of the weld cooling rates (as predicted by a Rosenthal analysis). The microstructures were characterized by X-ray diffraction, optical and by scanning electron microscopy. The plate-like phase found in the weld microstructures was identified as TiB2 occurring upon rapid solidification of the melted weld metal.

In Situ High-Energy X-Ray Diffraction Studies of Melting, Solidification and Solid-State Transformation of Ni3Sn

MRS Advances ◽  
2020 ◽  
Vol 5 (29-30) ◽  
pp. 1529-1535 ◽  
Author(s):  
Rijie Zhao ◽  
Jianrong Gao ◽  
Yang Ren
Keyword(s):  
Solid State ◽  
Elevated Temperatures ◽  
High Energy ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
State Transformation ◽  
Solid State Transformation ◽  
X Ray ◽  
Melting And Solidification

AbstractMelting, solidification and solid-state transformation of the intermetallic Ni3Sn compound were investigated in situ using synchrotron high-energy X-ray diffraction. It was observed that the compound undergoes a hexagonal to cubic transition before melting. In solidification, a disordered cubic phase crystallizes from the liquid at a large undercooling but it is reordered prior to bulk solidification. In melting and solidification, forced or natural flows are active bringing about significant changes of crystal orientations. These in situ observations provided insights into phase transformations of Ni3Sn at elevated temperatures and their roles in formation of metastable microstructure consisting of coarse grains and subgrains.

scholarly journals Correction: Fe(ii)(aq)uptake of Mg(ii)–Al(iii)/Fe(iii)–SO4/CO3HTLCs under alkaline conditions: adsorption and solid state transformation mechanisms

RSC Advances ◽  
2014 ◽  
Vol 4 (104) ◽  
pp. 60112-60113
Author(s):  
Mario A. Gomez ◽  
M. Jim Hendry ◽  
Samir Elouatik ◽  
Joseph Essilfie-Dughan ◽  
Susanta Paikaray
Keyword(s):  
Solid State ◽  
State Transformation ◽  
Solid State Transformation ◽  
Alkaline Conditions ◽  
Transformation Mechanisms

X-ray diffraction from one-dimensionally disordered 2H crystals undergoing solid state transformation to the 6H structure. III. Comparison with experimental observations on SiC

1980 ◽  
Vol 369 (1739) ◽  
pp. 463-477 ◽  
Keyword(s):  
Solid State ◽  
Deformation Mechanism ◽  
X Ray Diffraction ◽  
Fault Probability ◽  
State Transformation ◽  
Solid State Transformation ◽  
Simple Estimate ◽  
X Ray ◽  
Displacement Mechanism ◽  
Diffraction Effects

The diffraction effects predicted theoretically in the preceding two papers for 2H crystals undergoing solid state transformation to the 6H structure by the layer displacement mechanism and the deformation mechanism are compared with those experimentally observed on SiC. It is shown that the observed diffraction characteristics can be explained in terms of the layer displacement mechanism and not the deformation mechanism. A simple estimate of the layer displacement fault probability in two transformed 6H SiC crystals has been made by analysing the halfwidth of the experimentally obtained intensity profiles of the 10. L reflexions. It is also shown that the presence of a small concentration of growth faults in the as-grown 2H SiC crystal does not alter the basic diffraction characteristics predicted in part I of this series of papers.

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