In our life, copper products can be seen everywhere. There are many kinds of brass, white copper, red copper, bronze and so on. So, what's the difference between so many copper types? How should they be distinguished?

Pure copper

Pure copper is called red copper, also known as red copper. It has good plasticity, excellent conductivity and thermal conductivity. It can be used for hot pressing and cold pressing at the same time. It is widely used in products such as cable, wire and special copper etching for electric spark.

Red copper with high purity has fine structure, low oxygen content, no trachoma, pores and excellent conductivity. It is very suitable for electric etching molds. After heat treatment, the electrode has no directionality, so it is very suitable for fine beating and fine beating

brass

An alloy of copper and zinc is called brass. If the constituent elements are only copper and zinc, then this is only the most common brass. This kind of brass is usually used to make water pipes, valves, internal and external connecting pipes of air conditioners and radiators.

If there are more than two constituent elements of brass, including lead, tin, manganese, nickel, iron, silicon and other elements, it is called special brass. This special brass has high hardness, high strength and strong chemical corrosion resistance.

Brass has strong wear resistance. The seamless copper pipe made of it is soft and has strong wear resistance. This special brass is widely used in condenser, low temperature pipeline, submarine transportation pipe, heat exchanger and other parts. Its copper content is only 62 ~ 68%.

White copper

If nickel is the main additive element of copper alloy, we call it white copper. White copper is divided into ordinary white copper of copper nickel binary alloy and complex white copper with iron, zinc, aluminum and manganese elements.

In industry, white copper can be divided into electrical white copper and structural white copper. Among them, the structural white copper is characterized by excellent mechanical properties, good corrosion resistance and beautiful color.

This kind of white copper is widely used, such as precision machinery, chemical machinery and glasses accessories. Electrical white copper has good thermoelectric properties. Among them, constantan and manganese copper are common materials for manufacturing varistors, precision resistors and precision electrical instruments.

bronze

Bronze has been used in China for more than 3000 years. It can be said that it is the earliest alloy used in China. Bronze originally meant copper tin alloy. Later, in order to facilitate management, all copper alloys except white copper and brass were uniformly called bronze.

In addition, the names of the main added elements are added in front to distinguish different kinds of bronze. Tin bronze with tin as the main additive has excellent casting performance, good mechanical performance and excellent friction reduction performance. It is very suitable for manufacturing turbines, gears and bearings. Lead bronze is now used as a bearing material in engines and grinders.

Aluminum bronze has excellent wear resistance, corrosion resistance and high strength. It is widely used in the manufacture of high load shaft sleeves, gears, marine propellers and so on. Phosphor bronze has good conductivity and high elastic limit. It is very suitable for manufacturing precision springs and electrical contact components.

So what was the ancient copper coin?

In ancient times, the materials of copper coins in different dynasties were also different. Bronze, brass, white copper and red copper were all used to cast copper coins.

Copper coins in ancient China were cast with copper alloy, because different alloys have different components, so copper coins will appear in different colors.

Generally speaking, the yellow copper coins were cast with copper zinc alloy, while the cyan copper coins were cast with copper tin alloy. In the first half of the Ming Dynasty, the material used for casting copper coins was generally bronze, while in the second half of the Ming Dynasty, brass was used.