. Transactions. Fig. 7.—Very unsound spot in bronze casting with 12 per cent, tin and 6 per CENT, zinc, etched LIKE FiG. 6. X Fig. 8.—Zinc-oxide inclusions in oxidized copper treated with 30 per cent, ZINC, unetched. X 200. 392 ^ NON-METALLIC INCLUSIONS IN BRONZE AND BRASS in three cases, as shown in Figs. 8, 9, and 10. Some of these appearidiomorphic, but they are distinguished from tin-oxide crystals by theirlighter color, smoother surface, without very dark outUnes, and morerounded form. Fig. 10 shows metal cast in a chill, hence the inclusionsare much smaller in it than in the others
. Transactions. Fig. 7.—Very unsound spot in bronze casting with 12 per cent, tin and 6 per CENT, zinc, etched LIKE FiG. 6. X Fig. 8.—Zinc-oxide inclusions in oxidized copper treated with 30 per cent, ZINC, unetched. X 200. 392 ^ NON-METALLIC INCLUSIONS IN BRONZE AND BRASS in three cases, as shown in Figs. 8, 9, and 10. Some of these appearidiomorphic, but they are distinguished from tin-oxide crystals by theirlighter color, smoother surface, without very dark outUnes, and morerounded form. Fig. 10 shows metal cast in a chill, hence the inclusionsare much smaller in it than in the others, which were cast in sand. IVlanganese and phosphorus, when added to oxidized copper, gaveresults like those first obtained with zinc; that is, no typical inclusionswere found although the castings were not sound. Fig. 11 shows theintercrystalline films produced when per cent, of phosphorus wasused to deoxidize some normal copper. These cavities seem to followalong the lines where the copper-oxide eutectic would be expected, hadthe metal not been deoxidized. Films that have been described as tinoxide are exactly similar
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Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
