Bubble growth, intermetallic compounds dissolution and their interactions during heating of an Al-5wt.%Mn alloy by in-situ synchrotron radiography

AbstractThe chemical disordering model for the electron irradiation induced crystalline to amorphous (C-A) transition was previously developed using in-situ experiments in the intermetallic compounds of the Cu-Ti binary alloy system. In the context of this model, a rule was developed which predicts the amorphisation tendency of these and other binary intertransition metal compounds with an accuracy of 92% in the 38 compounds studied to date. Two aspects of this rule, the composition of the compound and the crystal structure are examined through a first approximation computer comparison of ordered, partially ordered, and disordered crystal structures. It is found that in bcc based compounds and in complex crystal structure compounds, the ability of the chemical disordering to raise the energy of the crystal is severely inhibited at compound compositions away from 50:50. During the disordering process, the greatest increase of the crystal energy occurs during the early stages of chemical disordering. These results mesh well with the concept of an amorphous transition driven by the energy increase due to chemical disordering.

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In Situ Synchrotron Radiography and Spectrum Analysis of Transient Cavitation Bubbles in Molten Aluminium Alloy

Physics Procedia ◽

10.1016/j.phpro.2015.08.172 ◽

2015 ◽

Vol 70 ◽

pp. 841-845 ◽

Cited By ~ 24

Author(s):

I. Tzanakis ◽

W.W. Xu ◽

G.S.B. Lebon ◽

D.G. Eskin ◽

K. Pericleous ◽

...

Keyword(s):

Aluminium Alloy ◽

Spectrum Analysis ◽

Molten Aluminium ◽

Synchrotron Radiography ◽

Cavitation Bubbles

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Hydrogen Storage Properties, Metallographic Structures and Phase Transitions of Mg-based Alloys Prepared by Super Lamination Technique

MRS Proceedings ◽

10.1557/proc-1128-u01-04 ◽

2008 ◽

Vol 1128 ◽

Cited By ~ 2

Author(s):

Nobuhiko Takeichi ◽

Koji Tanaka ◽

Hideaki Tanaka ◽

Nobuhiro Kuriyama ◽

Tamotsu T Ueda ◽

...

Keyword(s):

Hydrogen Storage ◽

Intermetallic Compounds ◽

Activation Process ◽

Laminate Composites ◽

Hydrogen Storage Properties ◽

In Situ Xrd ◽

Recombination Processes ◽

Initial Activation ◽

Storage Properties

AbstractWe have prepared Mg/Pd laminate composites with (Mg/Pd)=6, 3 and 2.5 atom ratios, by a super lamination technique. The homogeneous Mg-Pd intermetallic compounds, Mg6Pd, Mg3Pd and Mg5Pd2, are formed during the initial activation process. We investigated the hydrogen storage properties of these materials. The compounds can reversibly absorb and desorb a large amount of hydrogen, up to 1.46˜0.9 H/M, at 573 K. Except for the Mg5Pd2-hydrogen system, the pressure composition-isotherms show two plateaux. The mechanism of the phase transition during hydrogenation/dehydrogenation was analyzed by in-situ XRD measurements. These intermetallic compounds absorb and desorb hydrogen through reversible multistage disproportionation and recombination processes.

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Metal hydride formation in palladium and palladium rich intermetallic compounds studied by in situ neutron diffraction

Powder Diffraction ◽

10.1017/s0885715613001000 ◽

2013 ◽

Vol 28 (S2) ◽

pp. S242-S255 ◽

Cited By ~ 6

Author(s):

H. Kohlmann ◽

N. Kurtzemann ◽

T. C. Hansen

Keyword(s):

Intermetallic Compounds ◽

Powder Diffraction ◽

Neutron Powder Diffraction ◽

Gas Pressure ◽

Type Structure ◽

Sapphire Crystal ◽

Direct Reaction ◽

Β Phase ◽

In Situ Neutron Diffraction

In order to investigate the hydrogenation of intermetallic compounds, a gas pressure cell for in situ neutron powder diffraction based on a sapphire crystal tube was constructed. By proper orientation of the single crystal Bragg peaks of the container material can be avoided, resulting in a very low diffraction background. Using a laser heating and gas pressure controller, the hydrogenation (deuteration) of palladium and palladium rich intermetallics was studied in real time up to 8 MPa gas pressure and 700 K. Crystal structure parameters of palladium deuterides could be obtained under various deuterium gas pressures, corresponding to compositional ranges of 0.04≤x≤0.11 for the α-phase and 0.52≤x≤0.72 for the β-phase at 446 K. In situ neutron powder diffraction of the deuteration of a thallium lead palladium intermetallic Tl1-xPbxPd3 shows two superstructures of the cubic closest packing (ccp) to transform independently into a AuCu3 type structure. This proves a direct reaction to the deuterium filled AuCu3 type structure instead of a reaction cascade involving different ccp superstructures and thus gives new insights into the reaction pathways of palladium rich intermetallic compounds.

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