Characteristics of copper

Pure red copper should be called red copper with the following properties.

- High thermal and electrical conductivity. In terms of electrical conductivity, it is second only to Ag, with a purity of 99.9% Cu in the annealing state, at 20oC resistivity suất = 1,7241Ω.cm and thermal conductivity of 385W / m. oK. Most pure copper is used as a wire. It should be remembered that the impurities dissolved in Cu, especially P, Fe in very small amounts also significantly reduce the electrical conductivity (0.1% P decreases 46%, 0.1% Fe decreases 23%).

- Resistant to corrosion quite well in common environments: atmospheric, water, seawater or alkaline, organic acids.

- Highly flexible due to the A1 network, so it is easy to deform hot and cold, easy to make into semi-finished products, convenient for use.

- In the annealing state, although the durability is not high (with 99.97% Cu with σb = 220MPa, σdh = 70MPa), after plastic deformation, the strength increases very strongly (with ε = 60%, σb = 425MPa, σdh = 375MPa). For copper and alloys, cold deformation is a very important durable chemical measure.

- The welding properties of copper are quite good, but when the content of impurities, especially oxygen, increases, this advantage decreases significantly.

Can see the disadvantages of copper as follows.

+ Bulk density (γ = 8.94g / cm3).

+ Poor shearing due to flexible, not broken chips, to improve the Pb often.

+ Poor casting properties, although the melting point is 1083oC, but the dilution is small.