A detailed description of brass

Brass is a copper alloy with zinc as the main added element, with a beautiful yellow color, collectively called brass. Copper and zinc binary alloys are called ordinary brass or simple brass. Brass above three yuan is called special brass or complex brass. For α brass, the amount of brass is increasing as the δ increases. For brass α (β) brass, room temperature strength increases continuously before the zinc content increases to about 45%. If the zinc content is further increased, the strength is reduced sharply due to the emergence of a more brittle r phase (a solid solution based on the Cu5Zn8 compound) in the alloy tissue. The α plasticity β brass is always reduced with the increase of zinc content. Therefore, copper and zinc alloys with zinc content of more than 45% have no practical value. Brass alloys containing less than 36% zinc are composed of solid solutions and have good cold processing properties, such as brass containing 30% zinc are commonly used to make shell casings, commonly known as shell brass or 73 brass. Brass alloys containing zinc between 36% and 42% are made up of solid solutions, the most common of which is 64 brasses containing 40% zinc.
Common brass is used in a wide range of purposes such as water tank belts, water supply and drainage pipes, medals, bellows, serpents, condensation tubes, shell casings and a variety of complex shapes of punch products, small hardware and so on. With the increase in zinc content from H63 to H59, they are able to withstand thermal processing, mostly used in machinery and electrical parts, stamping parts and musical instruments. Brass castings are commonly used to make valves and pipe fittings.
Brass types and their corresponding types are only introduced: in order to improve the corrosion resistance, strength, hardness and cutting of brass, a small amount of copper-zinc alloys (generally 1% to 2%, a few up to 3% to 4%, very few up to 5% to 6%) tin, aluminum, manganese, iron, silicon, nickel, lead and other elements, forming three yuan, four yuan, or even five yuan alloy, that is, complex brass, also known as brass.
Aluminum brass: Aluminum can improve the strength, hardness and corrosion resistance of brass, but reduce plasticity, suitable for use in sea wheel condensing tubes and other corrosion-resistant parts. Tin brass: Tin can improve the strength of brass and corrosion resistance to seawater, so called naval brass, used as marine thermal equipment and propellers. It can be dissolved into the copper-based solid solution and strengthens. However, with the increase of tin content, the alloy will appear brittle r phase (CuZnSn compound), is not conducive to the plastic deformation of the alloy, so the tin content of tin brass is generally in the range of 0.5% to 1.5%. Commonly used tin brasses are HSn70-1, HSn62-1, HSn60-1, etc. The former α alloy, with high plasticity, can be processed for cold and hot pressure. The last alloy has two-phase tissue (α-β) and often has a small amount of r-phase, room temperature plasticity is not high, can only be deformed in the heat state. Lead brass: Lead improves the cutting performance of brass, which is commonly used as a watch part. Lead is actually insoluble in brass and is distributed over the crystal boundary in a free mass state. Lead brass has two types of α (α and β) according to its organization. α lead brass because of the harmful effects of lead, high temperature plasticity is very low, so can only be cold deformation or hot extrusion. Lead brass β α good plasticity at high temperatures and can be forged. Manganese brass: Manganese has a greater solubility in solid brass. The addition of 1% to 4% manganese to brass can significantly improve the strength and corrosion resistance of the alloy without reducing its plasticity. Manganese brass has (α plus β) tissue, commonly used in HMn58-2, cold and hot pressure processing performance is quite good. Iron brass: Iron improves the mechanical and process properties of alloys. Iron brass in the iron content is usually less than 1.5%, its tissue is (α plus β), with high strength and toughness, high temperature plasticity is very good, cold state can also be deformed. The commonly used number plate is Hfe59-1-1. Nickel brass: Nickel can significantly improve brass corrosion resistance in the atmosphere and seawater. Nickel also increases the recrystration temperature of brass, prompting the formation of finer grains. Nickel and copper can form a continuous solid solution, significantly expanding the α phase region. HNi65-5 nickel brass has a single-phase α tissue, has a good plasticity at room temperature, can also be deformed in the thermal state, but the content of impurity lead must be strictly controlled, no system will seriously worsen the thermal processing performance of the alloy.