Copper Bar

Product Introduction

Performance of purple copper rod:

1、 Ordinary performance
Purple copper rod is a relatively pure type of copper, which can generally be approximated as pure copper. It has good conductivity and plasticity, but its strength and hardness are relatively poor. Copper has excellent thermal conductivity, ductility, and corrosion resistance. The trace impurities in copper have a serious impact on its conductivity and thermal conductivity. Among them, titanium, phosphorus, iron, silicon, etc. significantly reduce conductivity, while cadmium, zinc, etc. have little effect. The solid solubility of sulfur, selenium, tellurium, etc. in copper is very low, and they can form brittle compounds with copper, which has little effect on conductivity but can reduce processing plasticity.
Copper has good corrosion resistance in the atmosphere, seawater, certain non oxidizing acids (hydrochloric acid, dilute sulfuric acid), alkalis, salt solutions, and various organic acids (acetic acid, citric acid), and is used in the chemical industry. In addition, copper has good weldability and can be processed into various semi-finished and finished products through cold and hot plastic processing. In the 1970s, the production of purple copper exceeded the total production of other types of copper alloys.
2、 Physical performance
The trace impurities in the copper rod have a serious impact on the conductivity and thermal conductivity of copper. Among them, titanium, phosphorus, iron, silicon, etc. significantly reduce conductivity, while cadmium, zinc, etc. have little effect. The solid solubility of oxygen, sulfur, selenium, tellurium, etc. in copper is very low, and they can form brittle compounds with copper, which has little effect on conductivity but can reduce processing plasticity. When ordinary copper is heated in a reducing atmosphere containing hydrogen or carbon monoxide, hydrogen or carbon monoxide easily reacts with cuprous oxide (Cu2O) at grain boundaries, producing high-pressure water vapor or carbon dioxide gas, which can cause copper to fracture. This phenomenon is often referred to as the "hydrogen disease" of copper. Oxygen is harmful to the weldability of copper. Bismuth or lead forms low melting point eutectic with copper, causing copper to become thermally brittle; When brittle bismuth is distributed in a thin film at grain boundaries, it causes copper to become cold brittle. Phosphorus can significantly reduce the conductivity of copper, but it can improve the fluidity of copper liquid and enhance weldability. Moderate amounts of lead, tellurium, sulfur, etc. can improve machinability. The room temperature tensile strength of annealed copper sheet is 22-25 kgf/mm2, elongation is 45-50%, and Brinell hardness (HB) is 35-45. The thermal conductivity of pure copper is 386.4w/(m.k)

The use of purple copper bars is much more extensive than that of pure iron, with 50% of copper being electrolyzed and purified into pure copper every year for use in the electrical industry. The purple copper mentioned here does need to be very pure, with a copper content of over 99.95%. A very small amount of impurities, especially phosphorus, arsenic, aluminum, etc., will greatly reduce the conductivity of copper. The presence of oxygen in copper (which is easily mixed with small amounts during copper smelting) has a significant impact on conductivity, and copper used in the electrical industry generally must be oxygen free copper. In addition, impurities such as lead, antimony, bismuth, etc. can prevent copper crystals from combining together, causing thermal brittleness and affecting the processing of pure copper. This high-purity copper is usually refined by electrolysis: impure copper (i.e. crude copper) is used as the anode, pure copper is used as the cathode, and copper sulfate solution is used as the electrolyte. After the current passes through, the impure copper on the anode gradually melts, and pure copper gradually precipitates on the cathode. Copper refined in this way; The purity can reach 99.99%.