What are the properties of brass?

Brass is an alloy of copper and zinc. If brass consists only of copper and zinc, it is called ordinary brass. Brass is often used in the manufacture of valves, water pipes, air conditioning inside and outside the machine connection pipe and radiator. A better understanding of brass characteristics is of great significance to the use of brass and the development of brass industry.

Mechanical properties of common brass properties: The mechanical properties of brass are different due to different zinc content. Figure 7 shows the curve of mechanical properties of brass with different zinc content. For alpha brass, both σb and δ increase with the increase of zinc content. For (α+β) brass, the strength at room temperature increases continuously until the zinc content increases to about 45%. If the zinc content is further increased, the strength of the alloy decreases sharply due to the appearance of more brittle r phase (Cu5Zn8 compound based solid solution) in the microstructure. The room temperature ductility of (α+β) brass decreases with the increase of zinc content.

Properties of special brasses: The α and β phases in special brasses are complex solid solutions of multiple elements, which have a greater strengthening effect, while the α and β phases in common brasses are simple Cu-Zn solid solutions, which have a lower strengthening effect. Although the zinc equivalents are equivalent, the properties of multicomponent solid solutions are not the same as those of simple binary solid solutions. Therefore, a small amount of multi hardening is a way to improve the properties of the alloy.

Lead brass characteristics: Lead is actually insoluble in brass, as a free particle distribution on the grain boundary. There are two kinds of leaded brass according to its structure: α and (α+β). Due to the harmful effect of lead, high temperature plasticity is very low, so it can only be cold deformation or hot extrusion. (α+β) lead brass has good plasticity at high temperature and can be forged. Tin brass: Adding tin to brass can significantly improve the heat resistance of the alloy, especially the ability to improve the corrosion resistance of seawater, so tin brass is known as "navy brass".

Manganese brass properties: Manganese has a greater solubility in solid brass. The strength and corrosion resistance of brass alloy can be significantly improved by adding 1% ~ 4% manganese without reducing its plasticity.

Fe-brass characteristics: In fe-brass, iron is precipitated by iron-rich particles, which is used as the crystal nucleus to refine the grain, and can prevent the recrystallization grain growth, so as to improve the mechanical and technological properties of the alloy. The iron content of iron brass is usually less than 1.5%, and its structure is (α+β). It has high strength and toughness, good plasticity at high temperature, and deformation at cold state. The common brand number is Hfe59-1-1.

Nickel brass properties: Nickel and copper can form continuous solid solution, significantly expanding the α phase region. The corrosion resistance of brass in atmosphere and seawater can be improved significantly by adding nickel to brass. Nickel can also increase the recrystallization temperature of brass and promote the formation of finer grains. HNi65-5 nickel-brass has a single-phase α structure, which has good plasticity at room temperature and can deform in hot state.

Brass has strong wear resistance. Special brass, also called special brass, has high strength, high hardness and strong chemical corrosion resistance. The mechanical properties of machining are also prominent. The seamless copper tube made of brass is soft and wear-resistant. Brass seamless pipe can be used in heat exchangers and condensers, cryogenic lines, submarine transport lines. Manufacturing sheet, bar, bar, pipe, casting parts, etc. Copper in 62% ~ 68%, plasticity, manufacturing pressure resistant equipment.

Brass is divided into ordinary brass and special brass according to the types of alloying elements contained in the brass. Brass for pressure working is called deformed brass.