1 BERYLLIUM COPPER.
a. this metal is a alloy of copper and beryllium and has the highest strength of any coper alloy. its can be heat-treated to give good wear resistance and other properties required for flat and wire springs. welding ordinarily decreases the strength of the metal in the heat-affected zone. this can be restored, however, by means of heat treatment. when beryllium copper is heated with the oxyacetylene flame, a hard, insoluble oxide is formed on the surface this oxide is difficult to remove. the most satisfactory method for joining beryllium copper is by means of silver soldering, for which the procedure is the some as that recommended any of the ferrous and nonferrous metal that can be joined by that process.
BRASS.
a. brass is an alloy of copper and zinc, although certain other metallic elements may be added to improve its physical properties.
b. naval brass is one of these alloys, consisting of 62percent copper, 0.50 to 1.50 percent tin ,up to 0.10 percent iron, and 0.20 percent lead, the remainder is zinc.it used for many purposes, especially where high strength, toughness, and resistance to corrosion are important.
c. ordinary machine brass contains 60 to 68 % copper and 32 to 40 % zinc whereas the high copper brass known as red brass contains 75 to 85 % copper and 15 to 25 % zinc these alloys have a low melting point and low heat conductivity.
BRONZE.
a. a bronze is an alloy consisting mainly of copper and tin and it may or not contain lead and zinc. nickel may also be added to these bronzes to give them white color. some of the various bronzes available are.
(1) aluminum bronze. aluminum bronze (84 to 93 % copper, 7 to 10 % aluminum and 4% iron, with the addition of small amount of other metals, including nickel, tin , and manganese ) is used for bearings and other part where high strength and corrosion resistance is required.
(2) manganese bronze, manganese bronze (57 to 60 % copper, 0.50 to 1.50% tin, 0.80 to 2 % iron, 0.50% manganese, and 0.25% aluminum, the remainder zinc ) is used where high strength and corrosion resistance, such as would be required in marine construction, is necessary.
(3) practically all brasses and bronzes may be welded by the oxyacetylene flame, and some can be welded with the carbon arc.in general, the filler rod used for gas welding operations should be of the some composition, approximately, as the alloy being welded.
COPPER.
a. copper is a red metal available in either the electrolytic or deoxidized forms. it is a very ductile and malleable metal, having high electrical and heat conductivity. it is used as a major element in the manufacture of several hundred commercial alloys. each one of these alloy has somewhat different welding characteristics. there are certain welding procedures, however, that apply to all.
b. pure cast copper is soft, tough and very malleable, while pure copper wire or sheet is much stronger than the cast from, due to the hardening and strengthening produced by the rolling, forging, or drawing operations. copper is softer than steel and can be hammered out to a thin edge.
c. commercially pure (electrolytic) copper contains a small amount of oxide and is not suitable for welding because a weak zone develops in the base metal adjacent to the weld. deoxidized or oxygen-free copper is entirely satisfactory for fusion welding, it is made by adding a small amount of silicon or manganese, phosphorus or boron , which removes the last trace of oxygen from the copper. the weldability of copper can be tested by heating piece of it to a bright red, just below the melting point and then hammering it vigorously on an anvil. it is breaks, it contains oxygen and is unsuitable for fusion welding.