Role of shear stiffening in reducing hydrogenation in intermetallic compounds

2006 ◽  
Vol 89 (20) ◽  
pp. 201909 ◽  
Author(s):  
I. Jacob ◽  
M. Bereznitsky ◽  
O. Yeheskel ◽  
R. G. Leisure
2007 ◽  
Vol 560 ◽  
pp. 97-102 ◽  
Author(s):  
Felipe García ◽  
Armando Salinas-Rodríguez ◽  
Enrique Nava-Vázquez

The reaction between solid steel and liquid Al-Zn-Si alloy leads to the formation of a solid intermetallic interfacial layer. In the case of industrial Al-43.5Zn-1.5Si coated steel strips, the thickness of the intermetallic layer is on average 1.35 μm and the kinetics of the reaction is controlled by the effect of Si on Al and Fe diffusivities through the solid intermetallic layer. In this paper it is shown that the thickness of the intermetallic interfacial layer decreases as the Si content in the liquid alloy increases. EDXS microanalysis at the interface of industrial coated steel strips shows that the interfacial intermetallic compounds are chemically similar to those formed in the bulk of Al-43.5Zn-1.5Si liquid baths in continuous coating lines. Differential acid dissolution of the coatings reveals that the intermetallic layer is not planar at the interface with the coating overlay and is formed by grains of different size and chemical composition. Addition of minute quantities of Ti to the Al-Zn-Si liquid alloy causes changes in the morphology of the intermetallic layer and an overall refining of the microstructure.


1988 ◽  
Vol 3 (3) ◽  
pp. 426-440 ◽  
Author(s):  
Osamu Izumi ◽  
Takayuki Takasugi

The present article first describes some characteristics of structure, chemistry, and electronic (bond) nature for grain boundaries in the A3B Li2-type intermetallic compounds. Next, the phenomenological aspects for the grain boundary brittleness of the Li2-type intermetallic compounds are reviewed with respect to the combination of the constituent atoms, the alloying effect, the stoichiometry effect, and a role of impurity or gaseous atoms. It is emphasized that the brittleness of grain boundaries in the intermetallic compounds is directly controlled by the atomistic and electronic structures at grain boundary regions. Based on these systematic investigations, it is suggested that the brittleness of the Li2-type intermetallic compounds can be manipulated by appropriate control of composition and the corresponding electrochemical bond environment at grain boundary planes and by control of test environment. Furthermore, some examples of the materials development are described.


MRS Bulletin ◽  
1993 ◽  
Vol 18 (2) ◽  
pp. 44-49 ◽  
Author(s):  
J.H. Westbrook

History is replete with examples of the enormous impact of data compilations in all fields of science and technology. The advantages and opportunities such aggregations confer include:• convenience of access,• condensation and homogenization of raw data,• formats tailored for the application,• perception of patterns,• detection of errors,• definition of gaps and inconsistencies, and• basis for formulating and testing theories.The opportunities in materials science, and specifically in the subfield of alloy design, are no fewer than in other fields of science. Indeed, as I have remarked in a review of the history of the development of understanding and application of intermetallic compounds, breakthroughs in this field have usually come about not from “a new technique, a unique experimental observation, or an abstruse theory… Rather it was the amassing of a critical volume of experimental data in the literature which permitted an individual with great insight to perceive an underlying pattern not previously apparent.”


2013 ◽  
Vol 752 ◽  
pp. 42-47
Author(s):  
Gréta Gergely ◽  
Alíz Molnár ◽  
Zoltán Gácsi

The European Union and Japan initiated the issue of RoHS, the directive about the restriction of hazardous substances, which prohibits certain hazardous substances in electronic equipment - including lead - application. Due to the directive the use of lead free solder alloys is spreaded, however the Pb in the form of contamination may be appear under technological process. The lead impurity has significant effect on microstrucutre and lifetime so it is necessary to carry out detailed examinations. In this paper the study of intermetallic compounds in six-element, Pb impured, thermal cycles test-subjected, Sn-Ag-Cu (SAC) solder alloy is demonstrated


2010 ◽  
Vol 654-656 ◽  
pp. 2863-2866 ◽  
Author(s):  
Young Hee Cho ◽  
Arne K. Dahle

Magnesium based hydrogen storage materials were prepared by a conventional melting and casting technique. Characterisation of microstructure and hydrogen sorption properties of the alloys was carried out. Additions of Al, Cu and Ni lead to the formation of eutectic mixtures, Mg-Mg17Al12, Mg-Mg2Cu and Mg-Mg2Ni, respectively, with an inter-lamellar spacing of a few hundred nanometers. 3d and 4d transition metals were also added to Mg based alloys and were found to form intermetallic compounds that were homogeneously dispersed in the alloys. The dehydrogenation rate of the Mg alloys was quantitatively analysed in order to determine the rate-limiting step for the hydrogen desorption kinetics. The catalysing role of each intermetallic compound for the hydrogen desorption kinetics is further discussed.


2016 ◽  
Vol 879 ◽  
pp. 631-636
Author(s):  
Antoine Gueydan ◽  
Eric Hug

X-Ray analysis was performed on copper-clad aluminum wires at 423 K and 673 K to follow their microstructural evolution and understand their strain behavior under creep deformation, potential operating load in automotive industry. The lifetime of the wires is found to be strongly dependent on the existence of an initial heat treatment and on the applied stress. Annealed drawn wires verify a traditional Norton law in the overall range of the stress level. Raw drawn wires exhibit a distinct two stage behavior with a breakdown around an applied stress of 0.7 times the yield stress. It is shown in this work that the intermetallic compounds between copper and aluminum play only the role of a mechanical bounding without affecting the strain rate of the wires.


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