Nickel-copper alloys phase diagram

Gup] Gupta, K.P., Rajendraprasad, S.B., Jena, A. K., The Copper-Iron-Nickel System , J. Alloy Phase Diagrams, 3(2), 116-127 (1987) (Crys. Stracture, Phase Diagram, Phase Relations, Review, 40)... 

Phase diagrams have been measured for almost any alloy system you are likely to meet copper-nickel, copper-zinc, gold-platinum, or even water-antifreeze. Some... 

Alloys are prepared commercially and in the laboratory by melting the active metal and aluminum in a crucible and quenching the resultant melt which is then crushed and screened to the particle size range required for a particular application. The alloy composition is very important as different phases leach quite differently leading to markedly different porosities and crystallite sizes of the active metal. Mondolfo [14] provides an excellent compilation of the binary and ternary phase diagrams for aluminum alloys including those used for the preparation of skeletal metal catalysts. Alloys of a number of compositions are available commercially for activation in the laboratory or plant. They include alloys of aluminum with nickel, copper, cobalt, chromium-nickel, molybdenum-nickel, cobalt-nickel, and iron-nickel. 

An equilibrium sample of a copper-nickel (Cu-Ni) alloy with a composition of 65 wt% nickel is prepared. With reference to the Cu-Ni phase diagram shown in Figures 4.6 and 4.8 ... 

One of the most important phase transitions occurs when a liquid transforms into a solid. A great deal of information concerning the microstmcture of the solid can be obtained from a consideration of the phase diagram of the material, even though phase diagrams refer to equilibrium conditions and solidification is rarely carried out so slowly as to be an equilibrium process. For example, consider the solidification of a simple nickel-copper alloy, from the point of view of the phase diagram, reproduced in Figure 8.2. 

Mos] Moser, Z., Zakulski, W., Spencer, R, Hack, K., Thermodynamic Investigations of Solid Copper-Nickel and Iron-Nickel Alloys and Calculation of the Solid State Miscibility Gap in the Copper-Iron-Nickel System , Calphad, 9(3), 257-269 (1985) (Phase Diagram, Phase Relations, Experimental, Thermodyn., Calculation, 44)... 

Gup] Gupta, K.P., The Cu-Fe-Ni (Copper-Iron-Nickel) System in Phase Diagram of Ternary Nickel Alloys , Indian Inst. Metals, Calcutta, (1), 290-315 (1990) (Review, Crys. Stractue, Phase Diagrams, Phase Relations, 38)... 

One of the most important attributes of nickel with respect to the formation of corrosion-resistant alloys is its metallurgical compatibility with a number of other metals, such as copper, chromium, molybdenum, and iron. A survey of the binary phase diagrams for nickel and these other elements shows considerable solid solubility, and thus one can make alloys with a wide variety of composition. Nickel alloys are, in general, all austenitic alloys however, they can be subject to precipitation of intermetallic and carbide phases when aged. In some alloys designed for high-temperature service, intermetallic and carbide precipitation reactions are encouraged to improve properties. However, for corrosion applications, the precipitation of second phases usually promotes corrosion attack. The problem is rarely encountered because the alloys are supplied in the annealed condition and the service temperatures rarely approach the level required for sensitization. 

Figpre 9.3 (a) The copper-nickel phase diagram, (b) A portion of the copper-nickel phase diagram for which compositions and phase amounts are determined at points. (Adapted from Phase Diagrams of Binary Nickel Alloys, P. Nash, Editor, 1991. Reprinted by permission of ASM International, Materials Park, OH.)... 

Consider the phase diagram for copper and nickel (Figure 9.3b) and alloy of composition Co at 1250°C, and let C , C, W , and Wi represent the same parameters as given earlier. This derivation is accomplished through two conservation-of-mass expressions. With the first, because only two phases are present, the sum of their mass fractions must be equal to unity that is,... 

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