How to distinguish between T1, T2 and T3 copper
T1, T2 and T3 are three grades of copper. The differences between these three grades of copper mainly include the following aspects:
1. Different copper contents
T1 pure copper has the highest content and is also the purest. T1 chemical composition: copper + silver CuAg: ≥99.95.
T2 copper refers to a copper-silver alloy, in which the copper + silver content of copper is >99.9%, that is, silver + copper + silver CuAq: 2999, and there is no requirement for phosphorus.
The copper content of T3 is, copper + silver CuAg; ≥99.70.
2. Different strengths
T1 pure copper mechanical properties tensile strength: ob (MPa) ≥ 295 elongation after break: 45% ~ 50% HBS: 35 ~ 40.
T2 copper tensile strength ab (Mpa)>195, back elongation: 45%~50% HBS: 35~40.
T3 copper tensile strength ab(MPal:>210. Elongation after break: 45%~50%HBS: 35~40. The tensile strength of T4 copper is lower
3. Different conductive properties
T1 pure copper has good conductivity, thermal conductivity, corrosion resistance and processing properties, and can be brazed and fiber welded. It contains less impurities that reduce electrical conductivity and thermal conductivity, and trace amounts of oxygen have little impact on electrical conductivity, thermal conductivity and processing properties.
T2 copper has good electrical and thermal conductivity, corrosion resistance and processing properties, and can be welded and brazed. It contains less impurities that reduce electrical conductivity and thermal conductivity. Trace amounts of oxygen have little effect on electrical conductivity, thermal conductivity and processing properties, but can easily cause "hydrogen disease".
T3 copper contains more impurities that reduce electrical conductivity and thermal conductivity, and has a higher gas content than T2. It is more likely to cause "gas disease" and cannot be processed (annealed, welded, etc.) and used in high-temperature reducing atmospheres.
4. Different resistances
T2 has low resistivity, high copper content, is relatively pure, and has high conductivity, while T3 has high resistivity.
T3 ordinary pure copper, ordinary pure copper for high conductivity, is an oxygen-containing copper with a mass fraction of not less than 99.7% copper and very little impurities. It is commonly used in industry. The appearance is purple-red, so it is also called red copper. Its recrystallization temperature is 200-280 degrees Celsius.
T3 oxygen-free copper has no hydrogen embrittlement, high conductivity, good processing performance, welding performance, corrosion resistance and low temperature performance. Countries have different standards for oxygen content, and there are some differences. OFC (oxygen-free copper): metallic copper with a purity of 99.995%. Generally used in electrical and electronic applications such as audio equipment, vacuum electronic devices, cables, etc.
Among them, oxygen-free copper includes LC-OFC (linear crystalline oxygen-free copper or crystalline oxygen-free copper): with a purity of more than 99.995% and OCC (single crystal oxygen-free copper): with a purity of more than 99.996%, and is divided into PC-OCC and UP-OCC et al. Single crystal oxygen-free copper manufactured using UP-OCC technology (Ultra Pure Copper by Ohno Continuous Casting Process) has no directionality, high purity, corrosion resistance, and extremely low electrical impedance, making the wire suitable for high-speed and excellent signal transmission.
T3 chemical composition:
Copper+Silver CuAg: ≥99.70
Lead Pb: ≤0.01
Bismuth Bi: ≤0.002
Note: ≤0.3 (impurity)
T3 is prone to hydrogen embrittlement in reducing media containing hydrogen, commonly known as hydrogen disease, so it is not suitable to be processed and used in reducing media with temperatures above 370 degrees Celsius: its strength will increase below -250 degrees Celsius.
T3 is fire-refined copper, containing more copper and impurities. It has good electrical conductivity, thermal conductivity, corrosion resistance and processing performance, and can be welded and brazed. T3 is mainly used for structural materials, such as making electrical openings, gaskets, rivets, nozzles, and various conduits, etc. It is also used for less important conductive originals.
Red copper is not necessarily pure copper. Sometimes a small amount of degassing elements or other elements are added to improve the material and performance, so it is also classified as a copper alloy. China's red copper processing materials can be divided into: ordinary red copper (T1, T2, T3), oxygen-free copper (TU1, TU2 and high-purity, vacuum oxygen-free copper), deoxidized copper (TUP, TUMn) and special ones with a small amount of alloying elements added. There are four types of copper (arsenic copper, tellurium copper, and silver copper).
