Copper-silver alloy

Eig. 1. Gradation of color of gold—copper—silver alloys (81). 

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

In the presence of metallic copper, metallic silver, or a copper-silver alloy used in the form of gauze or as metal deposited on a low surface area inert support, methanol can be dehydrogenated to formaldehyde at 400—500°C. 

A synthetic mixture containing 0.1541 g of CaC20A H20 and 0.0453 g of MgC204 2H20 gave = 0-0427 g, compared with a theoretical value of 0.0422 g. A similar determination was carried out for the determination of a copper-silver alloy from a mixture of the metal nitrates. 

The classical method for the preparation of Mo, Fe, Co and Ni carbonyls consists of a direct reaction of CO with the respective metal at high pressures (150-200 atm.) and temperatures (100-200 C). Under these conditions steel is generally attacked by CO with formation of Fe(CO)s, so that pressure vessels fully lined with a CO-resistant material (e.g., copper-silver alloy) must be used. Since such special autoclaves are not normally found in general-purpose chemical laboratories, this compilation of carbonyl syntheses will be restricted to preparative methods which are compatible with the usual laboratory apparatus, i.e., atmospheric-pressure syntheses or those requiring simple steel autoclaves. 

Is it possible to have a copper-silver alloy that, at equilibrium, consists of a 8 phase of composition 92 wt% Ag-8 wt% Cu and also a liquid phase of composition 76 wt% Ag-24 wt% Cu If so, what will be the approximate temperature of the alloy If this is not possible, explain why. 

Consider 2.5 kg of a 80 wt% Cu-20 wt% Ag copper-silver alloy at 800T. How much copper must be added to this alloy to cause it to completely solidify SOOT ... 

A copper-silver alloy is heated to 900°C and is fonnd to consist of a and liquid phases. If the mass fraction of the liquid phase is 0.68, determine... 

The microstructure of a copper-silver alloy at O 775°C (1425°F) consists of primary a and eutectic structures. If the mass fractions of these two microconstituents are 0.73 and 0.27, respectively, determine the composition of the alloy. 

But there are further levels of intrigue to unfold here. The male/female pair on the lid of the tomb were wearing diadems in copper-silver alloy, an unusual amalgamation, while the male inhumation inside the tomb was equipped with a belt (or perhaps another diadem) in this metal and both were decorated in the same manner. The male/female pair wore veils, traces of which still remained. 

---