Types and characteristics of copper and copper alloys
Copper is one of the representative non-ferrous metal materials necessary for industry and daily life, with many types. Its practical history has a long history, having been unearthed in Egyptian tombs as early as 400 BC, making it a familiar material that has long been used in countries around the world. The types and properties of many coppers and copper alloys that are now in practical use are incomparable to those at that time, but the basic properties of copper have not changed much. There are properties that iron does not possess that make copper such a useful material.
Properties of copper and copper alloys
Copper's best properties are its workability, electrical conductivity, and thermal conductivity. As can be seen from the example of copper wire, this material has the highest electrical and thermal conductivity after silver and is used in many electrical parts, motors, wiring and circuit boards.
It is said that one of the reasons why copper has been widely used since ancient times is that it is easy to process. It is a representative metal with excellent ductility and is easy to perform plastic processing such as rolling and extrusion. Copper also has a beautiful finished surface and comes in a variety of colors, which is part of the reason we see it everywhere.
In addition, it has excellent hot forging performance and is suitable for processing complex products. It also has excellent spring properties and uses copper alloys with high fatigue strength such as beryllium copper and phosphor bronze. Unlike steel materials, its structure will not be destroyed even at extremely low temperatures, making it a material with excellent low-temperature brittleness. It also has excellent corrosion resistance, and since it is a precious metal, it is said to resist corrosion from contact.
Generally speaking, their use temperature is below 200°C, and even with excellent heat resistance, the maximum use temperature is around 250°C to 300°C. There are some copper alloys, such as white copper, that can be used at temperatures above 400°C. On the other hand, it does not become brittle at very low temperatures and can therefore be used without any problems.
All kinds of copper materials
By type, copper includes pure copper, brass, bronze, cupronickel, nickel silver, cupronickel and beryllium copper. In addition to pure copper, it is a copper alloy composed of copper and zinc, lead, tin, aluminum, nickel, etc. alone or in combination.
Additionally, there are two types of copper depending on the manufacturing method: rolled copper products and cast products. In fact, nearly 90% of copper products are considered rolled copper products. Brass is also the most commonly used material among copper alloys, and pure copper and brass are said to account for the majority of copper demand.
copper symbol
The representation symbol for copper materials (copper elongation) also matches these classifications. Copper and copper alloys such as C1020 (oxygen-free copper) are represented by the letter C and a four-digit number in the JIS standard. The 1000 series of C1 is pure copper or an alloy containing a large amount of copper, and is a category that also includes C17 beryllium copper and C19 titanium copper. The 2000 series such as C2801, C2700, etc. are copper-zinc Cu-Zn copper alloys such as brass and red bronze, and the 3000 series such as C3604 are free-cutting brass, with Pb added to improve processability. The 4000 series is Cu-Zn-based navy brass with Sn (tin) added, the C5000 series is phosphor bronze (Cu-Sn-P alloy), of which C5191 is a typical example, and the 6000 series such as C6161 and C6191 are aluminum bronze, used for musical instrument valves Brass, high-strength brass, C7351 and other 7000 series are available in nickel silver and white copper (copper-nickel alloy). We will briefly describe the properties of each copper alloy on its page.
Typical physical properties of copper
Melting point: about 1084℃
Boiling point: about 2360℃
Specific heat (20℃) 385J/kg·℃
Density 8.96g/cm3 (20℃)
Longitudinal elastic modulus (Young's modulus) 117.7kN/mm2
Thermal expansion coefficient (20-100℃) 16.8x10-6/℃
Conductivity 100%IACS
Resistivity (20℃) 1.7241μΩ·cm
Temperature coefficient of resistance (20℃) 0.00397/℃
Magnetic susceptibility -0.080x10 ^-6 cgs unit/gram
