scholarly journals Defects induced by solid state reactions at the tungsten-silicon carbide interface

2018 ◽  
Vol 123 (16) ◽  
pp. 161565 ◽  
Author(s):  
S. M. Tunhuma ◽  
M. Diale ◽  
M. J. Legodi ◽  
J. M. Nel ◽  
T. T. Thabete ◽  
...  
1993 ◽  
Vol 322 ◽  
Author(s):  
D. Zeng ◽  
M. J. Hampden-Smith ◽  
L.-M. Wang

AbstractCo-reduction of mixtures of MoCl3(THF)3 and SiCls4 in THF using Li/C10H8 or both Li/C10Hs8 and LiBEt3H resulted in formation and separation of black powders which upon thermal annealing at temperatures ranging from 750°C to 1 100°C produced crystalline molybdenum silicide and silicon carbide composite. Co-reduction of mixtures of WCI4 and GeBr4 with LiBEt3H in THF formed W2C and elemental Ge which upon thermal treatment at 750°C for 4 hours generated a small amount of crystalline W5Ge3.


2008 ◽  
Vol 6 (3) ◽  
pp. 413-417 ◽  
Author(s):  
Yiguang Wang ◽  
Qiaomu Liu ◽  
Litong Zhang ◽  
Laifei Cheng

Author(s):  
L. A. Bendersky ◽  
W. J. Boettinger

Rapid solidification produces a wide variety of sub-micron scale microstructure. Generally, the microstructure depends on the imposed melt undercooling and heat extraction rate. The microstructure can vary strongly not only due to processing parameters changes but also during the process itself, as a result of recalescence. Hence, careful examination of different locations in rapidly solidified products should be performed. Additionally, post-solidification solid-state reactions can alter the microstructure.The objective of the present work is to demonstrate the strong microstructural changes in different regions of melt-spun ribbon for three different alloys. The locations of the analyzed structures were near the wheel side (W) and near the center (C) of the ribbons. The TEM specimens were prepared by selective electropolishing or ion milling.


Author(s):  
S.R. Summerfelt ◽  
C.B. Carter

The wustite-spinel interface can be viewed as a model interface because the wustite and spinel can share a common f.c.c. oxygen sublattice such that only the cations distribution changes on crossing the interface. In this study, the interface has been formed by a solid state reaction involving either external or internal oxidation. In systems with very small lattice misfit, very large particles (>lμm) with coherent interfaces have been observed. Previously, the wustite-spinel interface had been observed to facet on {111} planes for MgFe2C4 and along {100} planes for MgAl2C4 and MgCr2O4, the spinel then grows preferentially in the <001> direction. Reasons for these experimental observations have been discussed by Henriksen and Kingery by considering the strain energy. The point-defect chemistry of such solid state reactions has been examined by Schmalzried. Although MgO has been the principal matrix material examined, others such as NiO have also been studied.


Author(s):  
W. A. Chiou ◽  
N. L. Jeon ◽  
Genbao Xu ◽  
M. Meshii

For many years amorphous metallic alloys have been prepared by rapid quenching techniques such as vapor condensation or melt quenching. Recently, solid-state reactions have shown to be an alternative for synthesizing amorphous metallic alloys. While solid-state amorphization by ball milling and high energy particle irradiation have been investigated extensively, the growth of amorphous phase by cold-rolling has been limited. This paper presents a morphological and structural study of amorphization of Cu and Ti foils by rolling.Samples of high purity Cu (99.999%) and Ti (99.99%) foils with a thickness of 0.025 mm were used as starting materials. These thin foils were cut to 5 cm (w) × 10 cm (1), and the surface was cleaned with acetone. A total of twenty alternatively stacked Cu and Ti foils were then rolled. Composite layers following each rolling pass were cleaned with acetone, cut into half and stacked together, and then rolled again.


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