Silver phase diagrams

As shown in the zinc-silver phase diagram in Figure 12.9, there are five identified solid phases. The extremes a and r are solids solutions and there are three intermetallic compounds p, y and e. In practice the addition of molten zinc to lead bullion followed by cooling will result in the formation of these intermetaUics as solid precipitates, which are mainly of the e form but also contain r] towards the... 

Fig. 2. Liquidus of isotherms of gold-copper-silver alloys and phase diagrams of the binary constituents (83).

Silicon is soluble in aluminum in the solid state to a maximum of 1.62 wt % at 577°C (2). It is soluble in silver, gold, and 2inc at temperatures above their melting points. Phase diagrams of systems containing silicides are available (2,3). 

Figure A1.27 shows the unusual silver-strontium phase diagram. It has four inter-metallic compounds. Note that it is just five simple phase diagrams, like the Pb-Sn diagram, stuck together. The first is the Ag-SrAgj diagram, the second is the SrAgj-Sr.Agj diagram, and so on. Each has a eutectic. You can always dissect complicated diagrams in this way.

Fig. 20.41 (a) Silver-copper phase. diagram and (b) magnesium-tin phase diagram... 

No phase diagram is available for the potassium-copper or potassium-silver systems. A diagram for the potassium-gold system shows the existence of four intermediate phases but later work shows that the phase identified as KAU4 1 diagram is in fact KAuj. 

Numerous compounds are observed in the Li-Ag phase diagram. The alloys are heated under Ar and cast in mild steel crucibles for metallographic examination, with homogeneity achieved by remelting under vacuum. Similar procedures were employed in an earlier study, except that H2 was used in place of Ar. An Ar cover gas was also employed to prepare the brasslike yj phase in the Li-Ag system for structural study. The silver and lithium were melted together in an iron crucible for 15-30 s before cooling without quenching to minimize the loss of lithium-. ... 

Phase diagrams for the systems silver/copper (limited solubility in the solid) and aluminum/silicon (formation of an eutectic mixture)... 

P. R. Subramanian and J. H. Perepezko, Ag-Cu (silver-copper) system, in Phase Diagrams of Binary Copper Alloys (P. R. Subramanian, D. J. Chakrabarti and D. E. Laughlin, eds.). Materials Park, OH ASM International, 1994. 

Other two-component systems may exhibit either limited solubility or complete insolubility in the solid state. An example with limited solubUity is the silver-copper system, of which the reduced-phase diagram is shown in Figure 13.5. Region L represents a liquid phase, with F = 2, and S and 5s represent solid-solution phases rich in Ag and Cu, respectively, so they are properly called one-phase areas. S2 is a two-phase region, with F= 1, and the curves AB and DF represent the compositions of the two solid-solution phases that are in equilibrium at any... 

Figure 7.5 An ab initio phase diagram for O2 interacting with Ag(l 11). [Reprinted with per mission from W. X. Li, C. Stampfl, and M. Scheffler, Insights into the Function of Silver as an Oxidation Catalyst by ab initio Thermodynamics, Phys. Rev. B 68 (2003), 165412 (Copyright 2003 by the American Physical Society).]...

Partial Miscibility in the Solid State So far, we have described (solid + liquid) phase equilibrium systems in which the solid phase that crystallizes is a pure compound, either as one of the original components or as a molecular addition compound. Sometimes solid solutions crystallize from solution instead of pure substances, and, depending on the system, the solubility can vary from small to complete miscibility over the entire range of concentration. Figure 14.26 shows the phase diagram for the (silver + copper) system.22 It is one in which limited solubility occurs in the solid state. Line AE is the (solid -I- liquid) equilibrium line for Ag, but the solid that crystallizes from solution is not pure Ag. Instead it is a solid solution with composition given by line AC. If a liquid with composition and temperature given by point a is... 

Consider a binary alloy of copper and silver. At a temperature near 850 °C and an alloy composition near 80% Cu-20% Ag, the phase diagram says that there should be a copper-rich solid and a liquid. Considering the pressure to be fixed at one atmosphere but allowing temperature variations,... 

The silver-copper phase diagram. Reprinted with permission of ASM International from L. A. Willey, Metals Handbook, vol. 8, 8th ed. (Materials Park, OH ASM, 1973), p. 259. All rights reserved, www.asminternational.org. 

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