Multicomponent alloys

The Tj-carbides are not specifically synthesized, but are of technical importance, occurring in alloy steels, stelUtes, or as embrittling phases in cemented carbides. Other complex carbides in the form of precipitates may form in multicomponent alloys or in high temperature reactor fuels by reaction between the fission products and the moderator graphite, ie, pyrographite-coated fuel kernels. 

Multiphase gold or palladium-based alloys never show dissolution of Au or Pd but often exhibit progressive surface ennoblement due to selective dissolution of copper or silver from the outer 2-3 atomic layers Heat treatment often decomposes multicomponent alloys into a Pd-Cu rich compound and an Ag-rich matrix with corrosion of the latter phase in deaerated artificial saliva and S -containing media . Au-Cu-rich lamellae have similarly been observed, again with preferential attack on Ag-rich phases or matrix. These effects presumably arise from the ability of the noble alloy phases to catalyse the cathodic reduction of oxygen . 

Formation of Alloys Between Group-IA Elements 7.2.4.2. Multicomponent Alloys... 

Verbrugge MW, Tobias CW (1985) A mathematical model for the periodic electrodeposition of multicomponent alloys. J Electrochem Soc 132 1298-1307... 

Nowadays, such hydride electrodes are used widely to make alkaline storage batteries which in their design are similar to Ni-Cd batteries but exhibit a considerably higher capacity than these. These two types of storage battery are interchangeable, since the potential of the hydride electrode is similar to that of the cadmium electrode. The metal alloys used to prepare the hydride electrodes are multicomponent alloys, usually with a high content of rare-earth elements. These cadmium-free batteries are regarded as environmentally preferable. 

Petzow, G. and Effenberg, G. (eds.) (1988 et seq.) Ternary Alloys. A Comprehensive Compendium of Evaluated Constitutional Data and Phase Diagrams (VCH, Weinheim). Prince, A. (1978) Multicomponent Alloy Constitution Bibliography 1955-1973 (The Metals Society, London). 

Methanation of C02 over Pd on zirconia and Ni on zirconia catalysts derived form amorphous Pd-Zr-, Ni-Zr-, and Ni-containing multicomponent alloys prepared by controlled oxidation-reduction treatment or generated under reaction conditions have been studied in detail. 

The best known heterogeneous catalysts are oxide-supported Ru, Rh, and Ni, and Ru exhibits the highest selectivity. Marked support effects are observed and Ti02 is usually found to be the best support material. Pd on zirconia and Ni on zirconia are particularly effective catalysts when prepared using amorphous Pd-Zr, Ni-Zr, and Ni-containing multicomponent alloys by controlled oxidation-reduction treatment240-242 or generated under reaction conditions.243-245 Stabilized metal nanoparticles of uniform dispersion embedded into the oxide matrix are the... 

To compose a kinetic scheme of process how to change the concentration profile of atoms in multicomponent alloys in vicinity of the flat surface in comparison with the similar alloy profile in vacuum at the process of an interaction of this alloy with gaseous molecules. Explain the cause of such concentration profile reorganization. 

If a binary or multicomponent alloy is undergoing the liquid-metal attack, then its dissolution can be either selective or non-selective. In the former case, the more soluble component dissolves at a higher rate. Hence, the solid phase becomes depleted, while the liquid enriched in this... 

Bimetallic alloy surfaces are also of great importance. Most metallic materials used commercially, and in particular metal-based, heterogenous catalysts, have multicomponent alloy phases. Despite their obvious importance, alloy single-crystal surfaces have not been studied so extensively in the past. A first step in understanding the chemistry of these surfaces is a thorough characterization of the structure of such surfaces. These attempts are part of efforts to overcome the material gap between commercial catalysts and surface-science studies. 

In accordance to the common rule of an increased glass ability in multicomponent alloys [4], the amorphous structure in Al-Ni-Ce-Sc ribbons appeared to be more stable than in Al-Ce-Sc ribbons an XRDP with a small a-Al peak of the type of Fig. 4c was registered only for the ribbon Al85Nii0Sc5 of 50 pm in thickness, and for the same ribbon of 35 pm in thickness no such peak was observed. The influence of Sc on the thermal stability in this group of alloys had a non-monotonous character introducing... 

Abstract Multicomponent alloys based on the Ti-Si system are attractive structural... 

Iron-, nickel-, and cobalt-based multicomponent alloys, some of which... 

Lead/thallium alloys which show good resistance against acids multicomponent alloys such as Pb/Sb/Sn/Tl may be used as carrier materials. 

Multicomponent alloys of nickel and aluminum activated by Ti, Mo are most widespread and wide by used materials for hydrogen electrodes of low temperature alkaline fuel cells. To make hydrogen electrodes skeletal nickel prepared by alkali-soluble of alloy with composition 50 %Ni -i- 47 % A1 -i-3 % Ti is used. Raney catalyst is processed by 20 % suspense of Fluoroplast F-4 D with following drying in vacuum at 50 °C that permits pyrophoric catalyst to protect against self combustion and serves hydrophobic binder to form electrodes [5]. 

Currently, more attention is being paid to properties of (Cr,Mo) steels and other commercial multicomponent alloys containing Cr and Mo, however, these works do not contain new information about the phase diagram of the Cr-Fe-Mo system. Some studies concerning intermetallic phases existing in the ternary system will be discussed briefly in the Miscellaneous section. 

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