Brass alloy

Naval brass (alloy 465) Naval stores Navane... 

Minor additions of arsenic (0.02—0.5%) to copper (qv) and copper alloys (qv) raise the recrystaUization temperature and improve corrosion resistance. In some brass alloys, small amounts of arsenic inhibit de2incification (22), and minimise season cracking. 

Phosphorized deoxidized arsenical copper (alloy 142 (23)) is used for heat exchangers and condenser tubes. Copper-arsenical leaded Muntz metal (alloy 366), Admiralty brass (alloy 443), naval brass (alloy 465), and aluminum brass (alloy 687), all find use in condensers, evaporators, ferrules, and heat exchanger and distillation tubes. The composition of these alloys is Hsted in Table 5. 

Brass alloys fall within the designation C205 to C280 and cover the entire soHd solution range of up to 35 wt % zinc in the Cu—Zn alloy system. 

Red Brass Alloys. In forming red brass alloys, which iaclude leaded red and leaded semired brasses, caution should be exercised to prevent gas absorption by flame impingement or the melting of oily scrap, or metal loss through excessive oxidation of the melt surface. To prevent excessive 2iac volatilization, the melt must be poured as soon as it reaches the proper temperature. The melt should be finally deoxidized and cast at ca 1065—1230°C as measured with a pyrometer. Fluxing is usually not needed if clean material has been melted. 

Properties of red brass alloys are given in Table 9. The members of this group are cast using the centrifugal, continuous, investment, and sand molding methods. General tensile strengths vary from 170 to 210 MPa (25,000—30,000 psi) minimum as cast in sand molds. 

Table 13. Properties of Silicon Bronze and Silicon Brass Alloys...

Dezincification Dezincification is corrosion of a brass alloy containing zinc in which the principal product of corrosion is metallic copper. This may occur as plugs rilling pits (plug type) or as continuous layers surrounding an unattacked core of brass (general type). The mechanism may involve overall corrosion of the alloy followed by redeposition of the copper from the corrosion products or selective corrosion of zinc or a high-zinc phase to leave copper residue. This form of corrosion is commonly encountered in brasses that contain more than 15 percent zinc and can be either eliminated or reduced by the addition ox small amounts of arsenic, antimony, or ph osphorus to the alloy. 

Brass (alloy of eopper and zine) used for ship s propellers, serews, wind instruments. 

Here are brief descriptions of these percussion primers. The Boxer primer consists of a metallic cup and anvil (both made from brass alloy ... 

The main alloys of copper are the brasses, alloyed with zinc, and the bronzes, alloyed with tin. Other, so-called bronzes are the aluminium bronzes and the silicon bronzes. 

Dezincification Some brass alloys are susceptible to pitting corrosion or loss of zinc from the metal matrix. This type of corrosion usually occurs when metal is in contact with high percentages of oxygen and carbon dioxide. 

The silver color is due to the plating of zinc on the penny. The final heating process causes the copper and zinc to fuse, producing a brass alloy. Brass is an alloy of zinc and copper. Typical brass alloys contain between 3% and 30% zinc. 

Figure 5.15 Influence of grain size on yield strength for a 70-30 Cu-Zn brass alloy. Reprinted, by permission, from W. Callister, Materials Science and Engineering An Introduction, 5th ed., p. 167. Copyright 2000 by John Wiley Sons, Inc.

Naval brass (alloy 465) - [ARSENIC AND ARSENIC ALLOYS] (Vol 3)... 

Copper is also highly reactive, forming oxides or halides (salts) when exposed to air and moisture. The green or blue products of corrosion found on copper and copper alloys are mixtures of copper salts and sulfates. Copper has been used in its native state, but more often in alloys such as brass or bronze. Most copper mined today is used in electrical wire and switches, and in brass alloys. 

The system Cu—Zn, the brass alloys, shows a great similarity to the system Cu—Sn, the bronze alloys, with the understanding that the corresponding compounds occur at equal ratios of atoms to electrons and not at equal atomic compositions (Table 27). 

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