Bronze representative alloys

FIGURE 16.8 These three artifacts represent the progress that has been made in the extraction of d-metals. (a) An ancient bronze chariot axle cap from China made from an alloy of metals that are easy to extract, (b) An early iron steam engine made from a metal that was moderately easy to extract once high temperatures could be achieved, (c) A twentieth-century airplane engine with titanium components that had to await high temperatures and advanced technology before the element became widely available. 

Compensation trends found for decomposition of formic acid on metal (and other) catalysts are represented diagrammatically in Fig. 7. Line I (Table III, Q) refers to reactions over nickel and copper (3, 190, 194, 236), gold (5,189,237), cobalt (137,194), and iron (194) the observations included in this group were obtained by selection, since other metals, which showed large deviations, were omitted [see also (5), p. 422], Line I is close to that calculated for the reaction catalyzed by nickel metal (Table III, R) (3, 137, 189-194, 238). Lines II (19,233) and III (3, 234, 235) (Table III, O and P) refer to decomposition on silver. The other lines were found for the same rate process on IV, copper-nickel alloys (190) V, oxides (47, 137), VI, tungsten bronzes (239) and VII, Cu3Au (Table III, S) (240a). 

Lead curse tablets from Roman Carthage contain variable amounts of very small metallic inclusions. Electron microprobe analysis confirmed these metallic inclusions were bronze, brass, and a Sn-Sb alloy. This was interpreted as possible evidence of lead metal recycling. Six samples were chosen to represent a range of tablets containing the minimum to the maximum number of inclusions. Thermal ionization mass spectrometry of the Pb isotopes in the curse tablets appear to define a mixing line, with the tablets containing the least number of inclusions plotting closest to the Tunisian lead ore isotope ratios. 

Cryogenic service is usually defined as temperatures below -100°C (-150°F). Properties of some cryogenic fluids are listed in Table 2.73. Valve materials for operation at temperatures down to -268°C (-450°F) include copper, brass, bronze, aluminum, 300-series stainless steel alloys, nickel, Monel, Durimet, and Hastelloy. The limitation on the various steels falls between 0° and -150°F (-17 and -101°C), with cast carbon steel representing 0°F (-17°C) and 3.5% nickel steel being applicable to -150°F (-101°C). Iron should not be used below 0°F (-17°C). 

A bronze alloy more representative of statuary bronzes (5% Sn and P) was also exposed at the four standard sites. The rural and Western marine sites again show corrosion rates less than half those of the eastern marine and the industrial site. The corrosion rates at the industrial and the marine site increase with exposure time for this alloy, in marked contrast to the usual pattern of declining corrosion rate with time. It is also curious that the measured loss of strength at the rural PA site is disproportionately large for its corrosion rate (1.4% vs 2.0% at the industrial site). 

All of these compounds are bactericidal and the ancients knew that they helped to prevent wounds from festering. Accordingly, Achilles has been represented in ancient pictures as scraping the rust or oxidation products from his bronze sword or spear into the wound of Telephusf. These oxidation products are frequently but incorrectly called verdigris, which latter is really a basic acetate of copper, and is not produced by ordinary atmospheric corrosion of the metal or its alloys. 

Let us begin our survey of other nonferrous metals with show me the money V The coinage metals consisting of copper, silver, and gold represent the first metals known to man. The first reports for copper purification date back to 3,500 B.C. in the Middle East bronze alloys were first introduced in ca. 3,000 B.C. in India and Greece. However, it is likely that earliest use for copper may have been much earlier for weaponry applications. As a testament to the durability of the coinage metals, 5,000 years after an Egyptian Pharaoh had copper pipes installed in his bath, those same pipes were discovered, dug up, and were still in sufficient shape to carry water ... 

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