Copper Alloys – Brass, Bronze and Cupronickels

Copper alloys have great材料特性对许多应用程序很有用。然而,纯铜, has been one of the most important metals for the last 6000 years. Comparing it to other metals, its biggest advantages are:

• 良好的电导率
• High thermal conductivity
• 强度和可塑性的显着混合物
• 在许多环境中耐腐蚀性

Those properties,including diamagnetism, of copper are also present in its alloys. A wide range of alloying elements add further desirable properties. While many copper alloys have suitable characteristics for different applications, they have largely been replaced by aluminium alloys and plastic materials.

The reason for that is copper’s comparatively high price. From all thedifferent types of metals，铜在价格表上非常高。

Still, brass, bronze and cupronickels have cemented their places as useful materials in different sectors, including engineering.

Brass

由于锌的溶解能力，添加锌为铜增强了合金。同时，铜合金的可塑性增加了，这是一个不寻常的特征。

10…20% Zn alloys are known as镀金金属在珠宝行业和热交换器的生产中使用。30％的Zn合金称为墨盒黄铜for a pretty self-explanatory reason. The upper threshold of zinc in formable brass is around 35%.

添加其他合金元素可以进一步改善黄铜的特性。例如，SN和AL增加了其在海水中的耐腐蚀性。

单相黄

申请：珠宝，艺术，深度绘制的零件（餐具，乐器等）和弹药弹药。

单相黄金含有高达37％的Zn。这些被称为α铜管。单相黄铜具有均匀的晶体结构。

Such brasses are softer and have higher ductility. Those qualities make alpha brasses suitable for cold working, drawing, bending, etc.

The aforementioned cartridge brass (70/30 Cu/Zn) falls into this category. Because of the suitability for cold drawing, it’s the ideal candidate for producing ammunition shells in large quantities without high energy requirements.

与具有较高锌含量的黄铜相比，它对腐蚀的耐药性使单相黄铜适合生产不同类型的紧固件。

Double Phase Brass

申请: Heat exchangers, capacitors, parts made by automatic cutting benches, etc.

Double phase brasses, also known as双工黄铜，同时包含α和β相。因此，存在α晶所结构和β晶粒结构。

双相黄铜比单相黄金更实惠，因为其中使用了大量的锌。同时，它更容易腐蚀。尽管如此，化学成分仍导致更大的强度和硬度。因此，双相黄铜适合热形成和铸造。金属挤出, stamping and die-casting are usable methods with that type of metal.

The most used alpha-beta brasses have a Cu/Zn relationship of 60/40. Such brasses are known asMuntz metals。我n order to improve material properties, double phase brasses have more alloying elements. Small amounts of Pb increase the material’s cutting properties. Mn, Sn, Al, Fe and Ni all have a significant impact on material strength.

含Mn的α-β黄铜被称为高强度黄铜。他们具有出色的铸造品质，但也用于热门工作。

Alpha-Beta黄铜的锌含量高达45％。上面的任何内容都是β黄铜，但发现使用量要少得多。

青铜

尽管人们通常以统一的含义了解青铜，但仍有几种分类。根据所使用的合金元素，青铜合金都具有不同的品质。

Tin Bronze

申请：弹簧，垫圈，硬币，艺术青铜板，泵的一部分，抗压铸件，轴承等。

The applications depend on the % of Sn used in the alloy. The maximum amount of Sn in alloys suitable for cold working is around 7%. Those copper alloys have good plasticity but are also easily work-hardened.

The maximum content of Sn is ca 20%. Starting from 5% of Sn, the structure of the alloy changes and they need some extraheat treatment。反过来，这会导致多孔结构。这也是为什么除了铸造之外，它们不适合其他形成方法的原因。

Adding phosphorus is necessary before the casting process. This helps with deoxidation. After the process, around 1% of phosphorus is left in the alloy, providing greater strength. Such alloys are calledphosphor bronzes。

双相锡青铜器的主要应用是制造different types of bearings。这样的结构达到了良好的平衡αphase assures resistance to blows and knocks, while the hard and brittle chemical compounds bear the load and provide some wear resistance.

Zn and Pb are also sometimes present in tin bronzes. Zn improves the quality of castings, while also making the alloy cheaper. This kind of bronze is also known asgun-metal, as large guns were made of this material in the past.

Small amounts of lead help to improve a bronze’s mechanical properties for cutting. Large amounts (up to 25%) are present inlead bronzesthat find use as bearing materials.

Aluminium Bronze

申请: Coins, ship parts, marine hardware, sleeve bearings, pumps, valves, etc.

Aluminium bronzes have similar characteristics to tin bronzes. These alloys, mostly, have a single phase and are suitable for cold forming. This makes aluminium bronze a popular choice as a coin material. The content of aluminium is usually somewhere between 6…12%.

双相铝制青铜发现用作铸造合金或进行热工作。Al含量约10％的铝制青铜用于制造螺旋螺旋桨，阀门，泵等。该金属适合在咸条件下或附近的海中使用。

杯子

申请: Coins, marine equipment, electrical devices, heat exchangers, cooling systems, ship building, etc.

铜 - 尼克合金强壮且塑料。将镍（通常为2…30％）添加到铜中，使金属高度耐腐蚀，并具有出色的电导率。

Cu-Ni合金在40…50％Ni时具有几乎不存在的热膨胀系数。同时，电阻最大。存在这种小型热膨胀系数，直到高达500°C的温度为止。

这就是为什么康斯坦坦（含45％镍的Cu-ni合金）用于发生巨大温度变化的电气设备的原因。例如，典型的君士坦坦使用正在形成一部分thermocouple。

耐腐蚀的Cu-Ni合金含有大约30％Ni以及一点点的FE和MN，这使得它们在盐水中特别稳定。