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HE003 - Independent verification of the saturation hydrogen uptake in MOF-177 and establishment of a benchmark for hydrogen adsorption in metal-organic frameworks

Hydrogen isotherms for MOF-177, Zn4O(1,3,5-benzenetribenzoate)2, crystals were independently measured by volumetric and gravimetric methods at 77 K to confirm its hydrogen uptake capacity and to establish the importance of calibrating gas adsorption instrumentation prior to evaluating H2 storage capacities. Reproducibility of hydrogen adsorption experiments is important because non-systematic errors in measurements can easily occur leading to erroneous reports of capacities. The surface excess weight percentage of hydrogen uptake in MOF-177 samples is 7.5 wt% at 70 bar, which corresponds to an absolute adsorbed amount of 11 wt%. These values are in agreement with our previous report and with those found independently by Southwest Research Institute. Considering its well-known structure and its significant H2 uptake properties, we believe MOF-177 is an excellent material to serve as a benchmark adsorber.


Hiroyasu Furukawa, Michael A. Miller and Omar M. Yaghi J. Mater. Chem., 2007, 17, 3197-3204

HE002 - Thermodynamische und katalytische Eigenschaften von Titan- und Cer-dotierten komplexen Aluminiumhydriden

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Thesis of Guido Streukens Fakultät für Chemie der Ruhr Universität Bochum Germany 2007

HE001 - Crystal structure determination and reaction pathway of amide-hydride mixtures

Combined synchrotron in situ X-ray diffraction and neutron diffraction studies were performed on 2:1 mixtures of lithium amide and magnesium hydride, which have shown promise as solid-state hydrogen storage materials. The dehydrogenated product is a mixed lithium and magnesium imide, Li2Mg(NH)2, whose crystal structure has not heretofore been determined. Furthermore, at elevated temperatures, Li2Mg(NH)2 undergoes two structural transitions from an orthorhombic structure to a primitive cubic structure at intermediate temperature (350 ?C) followed by a facecentered cubic crystal structure at high temperature (500 ?C). Disordering of the Li, Mg and cation vacancies as a function of temperature drives the structural transitions.We report the reaction pathway from in situ X-ray diffraction studies and the crystal structures of the three structural variants of Li2Mg(NH)2 as determined by high-resolution X-ray and neutron powder diffraction. We also report the hydrogen storage reaction pathways for mixtures with other cation ratios.


Job Rijssenbeek, Yan Gao, Jonathan Hanson, Qingzhen Huang, Camille Jones, Brian Toby Journal of Alloys and Compounds xxx (2007) xxx-xxx

G0018 - The hot-deformability and quantitative description of the microstructure of hot-deformed Fe-Ni superalloy

The paper presents the results of research concerning the influence of hot plastic forming parameters on the deformability and structure of a Fe-Ni austenitic alloy. The research was performed on a torsion plastometer in the range of temperatures of 900-1150 °C, at a strain rate 0.1 and 1.0 s-1. Plastic properties of the alloy were characterized by the worked out flow curves and the temperature relationships of flow stress and strain limit. The structural inspections were performed on microsections taken from plastometric samples after so called "freezing". The stereological parameters as the recrystallized grain size, inhomogenity and grain shape have been determined. Functional relations between the Zener-Hollomon parameter and the peak stress and the mean grain size have been developed and the activation energy of the hot plastic deformation has been estimated. The examination of substructure on TEM allowed the calculation of structural parameters: the average subgrain area and the mean dislocation density. A detailed investigation has shown that the substructure is inhomogeneous, consists of dense dislocation walls, subgrains and recrystallized regions.


K J Ducki, K Rodak, IOP Conf. Series: Materials Science and Engineering 22 (2011) 012011

G0017 - Influence of Constituent Materials on the Impact Toughness and Fracture Mechanisms of Hot-Roll-Bonded Aluminum Multilayer Laminates

Two aluminum multilayer laminates have been processed by hot roll bonding following similar processing paths. The first one is constituted by alternated Al 2024 and Al 1050 layers (ALH19) and the second one by alternated Al 7075 and Al 1050 layers (ADH19). The influence of the constituent materials in the multilayer laminates both during the processing at high temperature and during the subsequent mechanical characterization has been analyzed. The mechanical behavior of the as-received materials at the processing conditions has been characterized by hot torsion. Multilayer laminates have been tested at room temperature under impact Charpy tests, three-point bend tests, and shear tests on the interfaces. The relative toughness increase compared to the constituent materials was much higher for the ADH19 laminate based on the high-strength Al 7075 alloy than for the ALH19 laminate. This is attributed to the different fracture mechanism.


C.M. Cepeda-Jimenez, P. Hidalgo, M. Pozuelo, O.A. Ruano, and F. Carreno, Metallurgical and Materials Transactions A, Volume 41A, January 2010--61

G0016 - Study of hot deformation of an Al-Cu-Mg alloy using processing maps and microstructural characterization

The forming behaviour of an Al-Cu-Mg alloy (Al 2024-T351) has been studied by processing maps and microstructural characterization. Torsion tests were conducted in the range 278-467 °C, between 2.1 and 25.6 s?1. Stress-strain curves obtained from the experiment data were fitted using the Garofalo equation to obtain the constitutive parameters, obtaining a stress exponent of 6.1 and an activation energy of 180 kJ/mol. Electron backscatter diffraction (EBSD) was employed to characterize the microtexture and microstructure, before and after torsion testing, to evaluate the microstructural changes and instability phenomena. A peak ductility of the Al 2024 alloy was found at about 400 °C at all strain rates considered. According to the processing maps and microstructure observation, the optimum hot deformation condition for the Al 2024 alloy is in the range 360-410 °C and 2.1-4.5 s?1. Under these favourable conditions a uniform and fine grain size is obtained by extended dynamic recovery (DRV), which leads to the formation of subgrain boundaries that progressively transform at large strains into new high angle grain boundaries


C.M. Cepeda-Jiménez, O.A. Ruano, M. Carsí, F. Carreno, Materials Science and Engineering A 552 (2012) 530- 539

G0015 - Binder phase structure in fine and coarse WC-Co hard metals with Cr and V carbide additions

The effects of the grain refining additions V, Cr and the level of dissolved W on the structure of the Co binder phase and the hcp/fcc were investigated in this work alongside WC grain size. V was found to be a more effective grain size suppressor in materials with a coarser starting carbide grain size while Cr was more effective for finer grain material when overall WC grain size distribution was taken into account. Grain refiners and W levels had a significant effect on WC grain morphology with V additions in high W samples having a rounded appearance. Cr additions at both high and low W concentrations had a more prismatic appearance. The large scale structure of the fcc Co phase as imaged by EBSD was affected by WC grain size and carbon balance with high W leading to larger regions of similar orientation than those with higher carbon balance. V additions increased the size of fcc areas of similar orientation while Cr additions reduced them. Both the effect of additions and increased W suppressed hcp formation with hcp suppression more marked in coarser WC materials than finer WC materials. It is intended that more information on the binder phase will aid future modelling and exploration of WC-Co hard materials


Jessica M. Marshall, Alexandra Kusoffsky, Int. Journal of Refractory Metals and Hard Materials 40 (2013) 27-35

G0014 - Technological plasticity studies of the FeAl intermetallic phase-based alloy

Results of hot torsion tests of the Fe-40Al-5Cr-0.2Mo-0.2Zr-0.02B alloy are presented in the paper. The alloy was obtained by melting in an induction furnace. The tests were carried out using a plastometer of the Sataram type in the temperature range of 1123-1273 K and strain rates of 0.06, 0.24, 0.48 and 2.42 s-1 that were close to those used in plastic working processes. In the alloy studied the super-plasticity phenomenon was observed. The shape of the flow curves indicated that dynamic recrystallisation occurred during the super-plastic deformation. This was confirmed by studies of the alloy structure. Also traces of dynamic recovery were observed. The value of the activation energy Q=343 kJ/mol for dynamical recrystallisation is close to the activation energy of aluminium diffusion in the FeAl phase. The results have revealed that cast FeAl-based alloy can be process by superplasic forming in the range 1123-1223 K at strain rates about 1 s-1.


M. Kupka, Intermetallics 12 (2004) 295-302

G0013 - Application des mesures magnétiques à la métallurgie


E. Alff and Cl. Bronner, Conférence au Cercle d'Etudes des Métaux (1973) 1-34

G0012 - Recyling cemented carbides without pollution sorting chargeing material for zinc process


K. Hirose, I. Aoki, Int. Conf. Process. Mater. Prop., 1st (1993) 845-848

G0011 - High-temperature thermogravimetric analysis. Influence of gas pressure on kinetics of reactions in the solid state

A magnetic balance apparatus has been set up to follow reactions in the solid state under controlled conditions of pressure and temperature (25-1000°) Magnetic properties are characteristic of solid structures, and thermomagnetic analysis (T. M. A.) can give the variations of the sample susceptibility during the course of a reaction (susceptibilities of the new phases and of initial compounds not yet transformed). By continuous measurement of this susceptibility with the Faraday method, the conversion degree of the synthesis can be obtained. T. M. A. has been used to study the influence of a gas on a solid-solid reaction in which no gas can be evolved or consumed. An example is given for iron tungstate synthesis: Fe203(s) + WO3(s) --> Fe2WO6(s). At 800° the reaction kinetics depends on the nature and the pressure of the gas.


G. Thomas and F. Ropital, Journal of Thermal Analysis 30 (1985) 121-128

E0387 - Experimental Approaches to the Thermodynamics of Ceramics above 1500°C

Traditionally, the nuclear and aerospace industries have been the main drivers behind the development of high-temperature materials. These applications demand a high degree of reliability and extensive characterization of every new material. There is a lack of experimental thermodynamic data above 1500°C even for HfO2, ZrO2, La2O3, Y2O3, and other constituents of widely used ceramic systems. Such data, as are available, were often obtained half a century ago using custom-built instruments. We review classic experimental approaches for the measurement of formation enthalpies, high-temperature enthalpy increments by the drop method, and also discuss more recent developments which include mass spectrometric measurements of vapor pressures, pulsed laser relaxation methods for heat capacity, and melting temperature determination and high-temperature oxide melt solution calorimetry in application to refractory compounds. Approaches to the experimental determination of phase diagrams at high temperature are introduced using studies of liquid immiscibility in the Zr(O)-UO2 system as an example. Thermal analysis above 2000°C is now possible with commercially available instruments, as shown by the first experimental measurements of the phase transition and fusion enthalpies of La2O3. New results on a premelting phase transition in Y2O3 in oxygen are reported from in situ synchrotron X-ray diffraction study on levitated samples.


Sergey V. Ushakov, Alexandra Navrotsky, J. Am. Ceram. Soc., 1-20 (2012)

E0386 - Thermodynamic assessment and experiments in the system MgO-Al2O3

Samples with alumina rich compositions in the system MgO-Al2O3 were investigated with DTA up to 2473 K. The peritectic reaction L+Al2O3?L+Al2O3? Spinel predicted from calculations was confirmed in this study. A critical literature review was done focusing on the degree of inversion of stoichiometric spinel MgAl2O4. Experimental results and the most reliable literature data were used for re-optimisation of thermodynamic parameters of the quasi binary system


Tilo Zienert, Olga Fabrichnaya, CALPHAD: Computer Coupling of Phase Diagrams and Thermochemistry 40 (2013) 1-9

E0385 - Crystallization characteristics and physico-chemical properties of indium-containing lithium iron aluminosilicate glasses

The crystallization characteristics, microhardness and chemical durability of glasses based on the Li2O-Al2O3-Fe2O3 (In2O3)-SiO2 system were investigated. The present work aims to study the effect of In2O3/Fe2O3 replacements on the crystallization and the resulting microstructure of the glass-ceramics. Very fine grained microstructure was mostly developed by In2O3/Fe2O3 replacements in the glass-ceramics. The crystalline phases formed after controlled heat-treatment of the glasses were ?-eucryptite ss, lithium meta- and di-silicate as well as two forms of pyroxene phases (LiFeSi2O6 and LiInSi2O6). The microhardness values of the resulting glass-ceramics were decreased with In2O3/Fe2O3 replacements while the chemical durability was improved. The obtained data were correlated to the type of the crystalline phases formed and the resulting microstructure. Promising glass-ceramic materials of fine microstructure and good chemical durability could be obtained.


S.M. Salman, S.N. Salama, Ebrahim A. Mahdy, Ceramics International 39 (2013) 395-402

E0384 - The crystallization process and chemical durability of glass-ceramics based on the Li2O-B2O3 (Fe2O3)-SiO2 (GeO2) system

The effect of partial replacements of GeO2 for SiO2 and Fe2O3 for B2O3 on the crystallization process of a Li2O-B2O3-SiO2 glass-ceramic was followed by means of differential thermal analysis (DTA), X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The chemical resistance of the glass-ceramics toward the attack of acid media was also determined. Results showed a decrease in both transition (Tg) and softing (Ts) temperatures by the replacement processes. Varieties of crystalline phases including Ge-lithium disilicate ss, lithium diborate, lithium metasilicate as well as lithium iron silicate ss containing germanium were formed in the crystallized glasses. The crystallization of meta- and/or disilicate and their proportions depend on both temperature and duration of the process. The chemical durability of the crystallized glasses was improved by the replacement processes. The obtained durability data depend on the nature, concentration of the crystalline phases formed, the nature of glassy matrix, and the microstructure of the glass-ceramics. The role played by the glass oxide constituents in determining crystal phases, their solid solutions, microstructure, and the chemical durability of the glass-ceramics was discussed


S.M. Salman, S.N. Salama, Ebrahim A. Mahdy, Ceramics International 39 (2013) 7185-7192

E0383 - Lithium and rubidium extraction from zinnwaldite by alkali digestion process: Sintering mechanism and leaching kinetics

Lithium and rubidium were extracted from zinnwaldite [KLiFe2 +Al(AlSi3)O10(F,OH)2] by (1) its sintering with and CaCO3 powders and (2) water leaching the obtained sinters--the alkali digestion process. The experimental results showed that sintering proceeded in three partly overlapping stages: (1) decomposition of zinnwaldite at temperature up to 800 °C, (2) formation of new phases in the temperature range between 750 and 835 °C, and (3) formation of amorphous glassy phase at temperature above 835 °C. Densification of the reaction mixture occurred via a liquid phase sintering at temperatures above 750 °C and diffusion of calcium, potassium, silicon and rubidium resulted in the formation of the new phases. The decomposition of zinnwaldite and the formation of the new phases increased extraction of lithium and rubidium. The formation of glassy phase probably hindered extraction of lithium but did not affect that of rubidium because of its outward diffusion to sinter's surface. The optimal extraction efficiencies of 84% of lithium and 91% of rubidium were achieved at sintering temperature of 825 °C and leaching temperature of 95 °C. The good fit of the hyperbolic and uniform reaction models to the leaching data indicated that dissolution of lithium and rubidium proceeded through two stages. Application of the shrinking core model showed that dissolution of lithium was controlled by diffusion. The formation of a layer of Ca(OH)2 on surface of sinters apparently slowed and then terminated dissolution of lithium and rubidium in the later stage of leaching.


H. Vu, J. Bernardi, J. Jandová, L. Vaculíková, V. Goliá, International Journal of Mineral Processing 123 (2013) 9-17

E0382 - Hydroxyapatite, fluor-hydroxyapatite and fluorapatite produced via the sol-gel method. Optimisation, characterisation and rheology

Currently, most titanium implant coatings are made using hydroxyapatite and a plasma spraying technique. There are however limitations associated with plasma spraying processes including poor adherence, high porosity and cost. An alternative method utilising the sol-gel technique offers many potential advantages but is currently lacking research data for this application. It was the objective of this study to characterise and optimise the production of Hydroxyapatite (HA), fluorhydroxyapatite (FHA) and fluorapatite (FA) using a sol-gel technique and assess the rheological properties of these materials. HA, FHA and FA were synthesised by a sol-gel method. Calcium nitrate and triethylphosphite were used as precursors under an ethanol-water based solution. Different amounts of ammonium fluoride (NH4F) were incorporated for the preparation of the sol-gel derived FHA and FA. Optimisation of the chemistry and subsequent characterisation of the sol-gel derived materials was carried out using X-ray Diffraction (XRD) and Differential Thermal Analysis (DTA). Rheology of the sol-gels was investigated using a viscometer and contact angle measurement


Christopher J. Tredwin, Anne M. Young, George Georgiou, Song-Hee Shin, Hae-Won Kim, Jonathan C. Knowles, dental Materials 29 (2013) 166-173

E0381 - Strong bonding between sputtered bioglass-ceramic films and Ti-substrate implants induced by atomic inter-diffusion post-deposition heat-treatments

Bioglasses (BG) are the inorganic materials exhibiting the highest indices of bioactivity. Their appliance as films for bio-functionalization of metallic implant surfaces has been regarded as an optimal solution for surpassing their limited bulk mechanical properties. This study reports on magnetron sputtering of alkali-free BG thin films by varying the target-to-substrate working distance, which proved to play an important role in determining the films' properties. Post deposition heat-treatments at temperatures slightly above the glass transformation temperature were then applied to induce inter-diffusion processes at the BG/titanium substrate interface and strengthening the bonding as determined by pull-out adherence measurements. The morphological and structural features assessed by SEM-EDS, XRD, and FTIR revealed a good correlation between the formations of inter-metallic titanium silicide phases and the films' bonding strength. The highest mean value of pull-out adherence (60.3 ± 4.6 MPa), which is adequate even for load-bearing biomedical applications, was recorded for films deposited at a working distance of 35 mm followed by a heat-treatment at 750 °C for 2 h in air. The experimental findings are explained on the basis of structural, compositional and thermodynamic considerations.


G.E. Stan, A.C. Popa, A.C. Galca, G. Aldica, J.M.F. Ferreira, Applied Surface Science 280 (2013) 530- 538

E0380 - Melting behaviour and homogeneity range of B2 CoAl and updated thermodynamic description of the AleCo system

The central part of the Al-Co phase diagram is dominated by the high-melting B2 CoAl phase. Although this phase is well-known since long and has been intensively investigated in the literature, neither its melting behaviour nor its homogeneity range is well established. Therefore, a series of Al-Co alloys in the composition range 30-60 at.% Co were produced and analysed by differential thermal analysis, scanning electron microscopy, and electron-probe microanalysis. The composition dependence of the melting temperatures was determined and from the analysis of heat-treated, two-phase CoAl + Al5Co2 samples, the Al-rich phase boundary of the CoAl phase and the Co-rich boundary of the Al5Co2 phase were established. The melting temperatures of CoAl were found to be significantly higher than previously reported in the literature; for the stoichiometric compound a value of 1673 °C was obtained. On the basis of these new results and further relevant literature data, the complete Al-Co phase diagram was finally thermodynamically re-assessed applying the CALPHAD technique. The optimized thermodynamic parameters not only give a good description of the new experimental data, but also fit very well to most of the literature data.


F. Stein, C. Heb, N. Dupin, Intermetallics 39 (2013) 58-68

E0379 - Transformation of rutile to TiO2-II in a high pressure hydrothermal environment

The high pressure transformation of rutile to TiO2-II with the ?-PbO2 structure is known to be kinetically hindered. In this study we show that a hydrothermal environment at 6 GPa and 650 °C provides appreciable rates for producing single phase bulk samples of TiO2-II. So obtained TiO2-II was characterized by scanning electron microscopy, powder X-ray diffraction, Raman and Far-IR spectroscopy. The structural properties are identical to TiO2-II from dry transitions. Transmission electron microscopy studies strongly indicate that Ostwald ripening processes play an important role in the hydrothermally assisted transformation and subsequent growth of TiO2-II crystals. TiO2-II is thermally stable to about 550 °C. At 600 °C the onset of the transformation to rutile is observed. The thermal expansion in the temperature range from room temperature to 500 °C is highly anisotropic, virtually affecting only the c unit cell parameter (?c=7.1(2)×10?6 °C?1). The pressure-temperature conditions for the hydrothermally assisted transformation of rutile are viable for industrial production settings, and in light of the large technological significance of TiO2, TiO2-II may present an interesting target for large-scale synthesis.


Kristina Spektor, Dung Trung Tran, Kurt Leinenweber, Ulrich Häussermann, Journal of Solid State Chemistry 206 (2013) 209-216


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