Intermetallic alloy

Interlevel wiring Intermediate Intermediate 300 Intermediate 325 Intermediates Intermetallic alloys... 

ELECTRON ENERGY LOSS SPECTROSCOPY AS A TOOL TO PROBE THE ELECTRONIC STRUCTURE IN INTERMETALLIC ALLOYS... 

Our work demonstrates that EELS and in particular the combination of this technique with first principles electronic structure calculations are very powerful methods to study the bonding character in intermetallic alloys and study the alloying effects of ternary elements on the electronic structure. Our success in modelling spectra indicates the validity of our methodology of calculating spectra using the local density approximation and the single particle approach. 

M. Yamaguchi, H. Inui, K. Kishida, M. Matsumuro and Y. Shirai, High-Temperature Ordered Intermetallic Alloys VI, edited by J. Horton, I. Baker, S. Hanada, R.D. Noebe and D. Schwartz (MRS Proc. 364, Pittsburgh, Pa, 1995), p. 3... 

The intermetallic alloy NiAl is discussed as a potential base alloy for high temperature structural materials. Its use is currently limited by low room temperature ductility and fracture toughness. Consequently, substantial research efforts have been directed towards understanding its mechanical behaviour [1, 2] so that detailed experimental [3, 4, 5] and theoretical [6, 7, 8] analyses of the deformation of NiAl are available today. 

Horton, J., Hanada, S., Baker, 1., Noebe, R. D. and Schwartz, D., editors, " High-Temperature Ordered Intermetallic Alloys VT, Materials Research Society, Pittsburgh, Vol. 364. 

D.R. Pank, M.V. Nathal, D.A. Koss. Deformation behaviour of NiAl-based alloys containing iron, cobalt and hafnium, in High Temperature Ordered Intermetallic Alloys V, 1. Baker, R.Darolia, J.D.Whittenberger, Man H. Yoo, ed., MRS, (1993), Vol. 288... 

Hot Dipped Coatings Major attempts have been made to improve the quality of aluminised steel strip. Requirements on coating thickness and uniformity have been imposed. It is the speed of sheet movement, length of path in the molten bath, temperature and composition of the bath that control the thickness of the intermetallic layer which lies below the aluminium outer surface. The process of intermetallic alloy formation is diffusion controlled, and it is usual that some dissolution of iron into the molten aluminium does occur at a rate, Ac/At, which is given by... 

The pulsed molecular beam cluster source has produced clusters of virtually every material—we have made clusters of even the most refractory transition metals, of group IIIB and IVB elements, and numerous oxides, carbides, and intermetallic alloys of these elements. 

Mat. Res. Soc. Symp. Proc., 133, High Temperature Ordered Intermetallic Alloys III, p. 243 (1988). 

Oranges, citric acid in, 6 632t ORBIT PRINT SELECT software, 18 243 Orbitrap, 15 662-663 Orb web, structure of, 22 630 Ordered intermetallic alloys, 13 530 Order, in amorphous semiconductor structure, 22 128-129 Ordering, in ternary semiconductor alloy preparation, 22 158-159 Order of addition, in large-scale... 

Another characteristic point is the special attention that in intermetallic science, as in several fields of chemistry, needs to be dedicated to the structural aspects and to the description of the phases. The structure of intermetallic alloys in their different states, liquid, amorphous (glassy), quasi-crystalline and fully, three-dimensionally (3D) periodic crystalline are closely related to the different properties shown by these substances. Two chapters are therefore dedicated to selected aspects of intermetallic structural chemistry. Particular attention is dedicated to the solid state, in which a very large variety of properties and structures can be found. Solid intermetallic phases, generally non-molecular by nature, are characterized by their 3D crystal (or quasicrystal) structure. A great many crystal structures (often complex or very complex) have been elucidated, and intermetallic crystallochemistry is a fundamental topic of reference. A great number of papers have been published containing results obtained by powder and single crystal X-ray diffractometry and by neutron and electron diffraction methods. A characteristic nomenclature and several symbols and representations have been developed for the description, classification and identification of these phases. 

Cahn, R.W. (1987) Antiphase domains, disordered films and the ductility of ordered alloys based on Ni3AT. In High-Temperature Ordered Intermetallic Alloys II, eds. Stoloff, N.S., Koch, C.C., Liu, C.T. and Izumi, O. (MRS, Pittsburgh), Vol. 81, p. 27. 

Problems in the relations between complex intermetallic alloys and clusters. After the previous short survey of cluster structures and some comments... 

Thermochemistry of cluster compounds. In this short summary of cluster structures and their bonding, a few remarks on their thermochemical behaviour are given, in view of a possible relationship with the intermetallic alloy properties. To this end we remember that for molecular compounds, as for several organic compounds, concepts such as bond energies and their relation to atomization energies and thermodynamic formation functions play an important role in the description of these compounds and their properties. A classical example is given by some binary hydrocarbon compounds. 

Miscellaneous, special processing techniques and heat treatments In the preparation of intermetallic alloys, both in massive quantities for commercial purposes, or as small specimens for laboratory investigations, very often the alloys must be subjected to selected and well-defined heat treatments, in some cases in addition to mechanical treatments, in order to have their full characterization and/or optimal performance. 

Introductory remarks. Phases related to the 1 3 stoichiometry and their derivative structures, either as point compounds or as solid solution ranges, are frequently found in binary and ternary intermetallic alloy systems. 

Researchers have tried to fabricate plates using many different metals— mainly, stainless steel, aluminum alloys, titanium alloys, nickel alloys, copper alloys, intermetallic alloys, and metal-based composites such as carbon fiber-reinforced aluminum alloys, carbon fiber reinforced copper alloys, etc. [26]. Although Ta, Hf, Nb, Zr, and Ti metals show good corrosion resistance and chemical stability [6], the cost of fhese metals is too high for them to be used as materials in metal plates. That is why relatively cheaper iron-based alloys, particularly stainless steel, have been popularly studied as plate material. In the following secfions, we will infroduce sfainless sfeel (SS) and SS plates, which have been extensively investigated and show promise for the final applications [6,11]. 

The Aoki group [218] has been developing intermetallic alloys based on a CaSi compound that is alloyed with Si, Al, Ge, Mg, and Sr. However, the alloys cannot compete with the LaNi -type or even TiFe because they absorb only slightly more than 2 wt.%H at 100°C and desorb at 200°C. 

Additional surface modifications on vapor deposited SiC fibers, including WC. TaC, TiN, B4C, Al, Ni and Fe, have been applied with varying degree of success (Wawner and Nutt, 1980 DeBolt, 1982 Wawner, 1988). After exhaustive trial and error, TiB is selected as an additional coating material to further prevent the diffusion-induced reactions between the SCS-6 fibers and matrix materials, including Ti alloys and Ti Al intermetallic alloys (e.g. Ti Al, TiAl and TiAl ) (Donncllan and Frazier, 1991 James et al., 1991). When the coated fiber is subjected to tensile... 

Chapter 10 provides an exhaustive description of how these techniques can be applied to a large number of industrial alloys and other materials. This includes a discussion of solution and substance databases and step-by-step examples of multi-component calculations. Validation of calculated equilibria in multi-component alloys is given by a detailed comparison with experimental results for a variety of steels, titanium- and nickel-base alloys. Further selected examples include the formation of deleterious phases, complex precipitation sequences, sensitivity factor analysis, intermetallic alloys, alloy design, slag, slag-metal and other complex chemical equilibria and nuclear applications. 

---