Generally, bronze is melted with copper and then put tin, called tin bronze, the main components are tin and copper; brass is melted with copper and then put zinc, called zinc brass, the main components are zinc and copper. Adding certain alloying elements (such as zinc, tin, aluminum, beryllium, manganese, silicon, nickel, phosphorus, etc.) to pure copper forms a copper alloy. Copper alloy has good electrical conductivity, thermal conductivity and corrosion resistance, as well as high strength and wear resistance. According to different compositions, copper alloys are divided into brass and bronze:
1. Brass is a copper alloy with zinc as the main alloying element. According to its chemical composition, brass is divided into two types: ordinary copper and special brass.
(1) Ordinary brass: Ordinary brass is a binary alloy of copper and zinc. Due to its good plasticity, it is suitable for manufacturing plates, bars, wires, pipes and deep-drawn parts, such as condenser tubes, radiator tubes, and mechanical and electrical parts. Brass with an average copper content of 62% and 59% can also be cast and is called cast brass.
(2) Special brass: In order to obtain higher strength, corrosion resistance and good casting performance, aluminum, silicon, manganese, lead, tin and other elements are added to the copper-zinc alloy to form a special brass. Such as lead brass, tin brass, aluminum brass, silicon brass, manganese brass, etc. ① Lead brass has excellent cutting performance and good wear resistance. It is widely used in the manufacture of clock and watch parts, and the production of bearing bushes and bushes by casting. ② Tin brass has good corrosion resistance and is widely used in the manufacture of sea-going ship parts. ③Aluminum in aluminum brass can increase the strength and hardness of brass and improve its corrosion resistance in the atmosphere. Aluminum brass is used to manufacture corrosion-resistant parts. ④The silicon in silicon brass can improve the mechanical properties, wear resistance and corrosion resistance of copper. Silicon brass is mainly used to manufacture sea-going ship parts and chemical machinery parts.
2. bronze
Bronze originally refers to copper-tin alloys, but it is customary in the industry to call copper alloys containing aluminum, silicon, lead, beryllium, manganese, etc., also bronze, so bronze actually includes tin bronze, aluminum bronze, aluminum bronze, beryllium bronze, and silicon bronze , Lead bronze, etc. Bronze is also divided into two types: pressure-processed bronze and cast bronze.
(1) Tin bronze: The copper-based alloy with tin as the main alloying element is called tin bronze. The tin bronze used in the tin bronze industry in Hebei has a tin content between 3% and 14%. Tin bronze with a tin content of less than 5% is suitable for cold working; tin bronze with a tin content of 5% to 7% is suitable for hot working; tin bronze with a tin content of more than 10% is suitable for casting. Tin bronze is widely used in shipbuilding, chemical industry, machinery, instrumentation and other industries. It is mainly used to manufacture bearings, bushings and other wear-resistant parts, springs and other elastic elements, as well as anti-corrosion and anti-magnetic parts.
(2) Aluminum bronze: A copper-based alloy with aluminum as the main alloying element is called aluminum bronze. The mechanical properties of aluminum bronze are higher than brass and tin bronze. The aluminum content of practical aluminum bronze is between 5% and 12%, and aluminum bronze containing 5% to 7% of aluminum has the best plasticity and is suitable for cold working. After the aluminum content is greater than 7% to 8%, the strength increases, but the plasticity drops sharply, so it is mostly used in the as-cast state or after hot working. Aluminum bronze has higher abrasion resistance and corrosion resistance in the atmosphere, sea water, seawater carbonic acid and most organic acids than brass and tin bronze. Aluminum bronze can be used to manufacture high-strength anti-wear parts such as gears, bushings, worm gears, and high-corrosion-resistant elastic components.
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