scholarly journals Mechanochemistry of Metal Hydrides: Recent Advances

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2778 ◽  
Author(s):  
Jacques Huot ◽  
Fermín Cuevas ◽  
Stefano Deledda ◽  
Kaveh Edalati ◽  
Yaroslav Filinchuk ◽  
...  

This paper is a collection of selected contributions of the 1st International Workshop on Mechanochemistry of Metal Hydrides that was held in Oslo in May 2018. In this paper, the recent developments in the use of mechanochemistry to synthesize and modify metal hydrides are reviewed. A special emphasis is made on new techniques beside the traditional way of ball milling. High energy milling, ball milling under hydrogen reactive gas, cryomilling and severe plastic deformation techniques such as High-Pressure Torsion (HPT), Surface Mechanical Attrition Treatment (SMAT) and cold rolling are discussed. The new characterization method of in-situ X-ray diffraction during milling is described.

2014 ◽  
Vol 996 ◽  
pp. 906-911 ◽  
Author(s):  
Souhail Benafia ◽  
Delphine Retraint ◽  
Benoit Panicaud ◽  
Jean Luc Grosseau-Poussard

In this paper, the effects of Surface Mechanical Attrition Treatment on the high-temperature oxidation of AISI 316L austenitic stainless steel are investigated. Samples treated with different conditions were oxidized at 650°C in order to study the effect of this type of nanocrystallisation on the oxidation resistance of the alloy concerned. X-ray diffraction and in-situ Raman spectroscopy were used to identify the oxides formed at the surface. The results indicate the presence of hematite and chromium oxides. Experimental results obtained by Raman spectroscopy were also used to study the stress evolution in Cr2O3films during isothermal conditions.


2013 ◽  
Vol 401-403 ◽  
pp. 635-638
Author(s):  
Ping Luo ◽  
Shi Jie Dong ◽  
Zhi Xiong Xie ◽  
Wei Yang ◽  
An Zhuo Yangli

TiC-TiB2 composite ceramics were successfully fabricated via planetary ball milling of 72 mass% Ti and 28 mass % B4C powders, followed by low temperature sintering process at 1200°C. The microstructure of the ball-milled powder mixtures and composite ceramics were characterized by Differential thermal analysis equipment (DTA), field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The results showed that the ball-milled powder mixtures (Ti and B4C powders) were completely transformed to TiC-TiB2 composite ceramics as the powders were milled for 60 h and sintered at 1200°C for 1 h. The formation mechanism of the TiC-TiB2 composite was discussed. The high energy ball milling and necessary sintering for the powder mixtures plays an important role in the formation of the composites.


2020 ◽  
Vol 20 (7) ◽  
pp. 4587-4590 ◽  
Author(s):  
Ádám Révész ◽  
Tony Spassov ◽  
Viktória Kovács Kis ◽  
Erhard Schafler ◽  
Marcell Gajdics

High energy ball milling and subsequent high-pressure torsion method was carried out on nanocrystalline Mg powders catalyzed by 5 wt.% Nb2O5 and 5 wt.% carbon nanotubes. In the present research two distinct milling routes were performed in order to reveal the influence of the processing conditions on the hydrogenation behavior of the investigated alloys. The hydrogen sorption behavior of the milled powders and the bulk disks was examined in a Sieverts’-type apparatus. Structural characterization of the catalyzed Mg powders and disks has been carried out by high-resolution transmission electron microscopy and X-ray diffraction.


2021 ◽  
Vol 52 (5) ◽  
pp. 1812-1825
Author(s):  
Sen Lin ◽  
Ulrika Borggren ◽  
Andreas Stark ◽  
Annika Borgenstam ◽  
Wangzhong Mu ◽  
...  

AbstractIn-situ high-energy X-ray diffraction experiments with high temporal resolution during rapid cooling (280 °C s−1) and isothermal heat treatments (at 450 °C, 500 °C, and 550 °C for 30 minutes) were performed to study austenite decomposition in two commercial high-strength low-alloy steels. The rapid phase transformations occurring in these types of steels are investigated for the first time in-situ, aiding a detailed analysis of the austenite decomposition kinetics. For the low hardenability steel with main composition Fe-0.08C-1.7Mn-0.403Si-0.303Cr in weight percent, austenite decomposition to polygonal ferrite and bainite occurs already during the initial cooling. However, for the high hardenability steel with main composition Fe-0.08C-1.79Mn-0.182Si-0.757Cr-0.094Mo in weight percent, the austenite decomposition kinetics is retarded, chiefly by the Mo addition, and therefore mainly bainitic transformation occurs during isothermal holding; the bainitic transformation rate at the isothermal holding is clearly enhanced by lowered temperature from 550 °C to 500 °C and 450 °C. During prolonged isothermal holding, carbide formation leads to decreased austenite carbon content and promotes continued bainitic ferrite formation. Moreover, at prolonged isothermal holding at higher temperatures some degenerate pearlite form.


2021 ◽  
Vol 800 ◽  
pp. 140249
Author(s):  
Juan Macchi ◽  
Steve Gaudez ◽  
Guillaume Geandier ◽  
Julien Teixeira ◽  
Sabine Denis ◽  
...  

2010 ◽  
Vol 504 ◽  
pp. S155-S158 ◽  
Author(s):  
J. Bednarcik ◽  
C. Curfs ◽  
M. Sikorski ◽  
H. Franz ◽  
J.Z. Jiang

2011 ◽  
Vol 21 (15) ◽  
pp. 5604 ◽  
Author(s):  
Zonghai Chen ◽  
Yang Ren ◽  
Yan Qin ◽  
Huiming Wu ◽  
Shengqian Ma ◽  
...  

2000 ◽  
Vol 639 ◽  
Author(s):  
Ryuhei Kimura ◽  
Kiyoshi Takahashi ◽  
H. T. Grahn

ABSTRACTAn investigation of the growth mechanism for RF-plasma assisted molecular beam epitaxy of cubic GaN films using a nitrided AlGaAs buffer layer was carried out by in-situ reflection high energy electron diffraction (RHEED) and high resolution X-ray diffraction (HRXRD). It was found that hexagonal GaN nuclei grow on (1, 1, 1) facets during nitridation of the AlGaAs buffer layer, but a highly pure, cubic-phase GaN epilayer was grown on the nitrided AlGaAs buffer layer.


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