Brass rods need to follow some technological requirements when they are manufactured.

(1) All elements without exception reduce the conductivity and thermal conductivity of copper rods. When elements are dissolved in copper rods, the lattice distortion of copper rods is caused, wave scattering occurs during directional flow of free electrons and resistivity increases. On the contrary, there are no solid solubility or few solid solubility elements in copper rods, which have little effect on the conductivity and thermal conductivity of copper rods. It should be noted that some elements are in copper rods. Medium solid solubility decreases sharply with the decrease of temperature. The precipitation of elemental and metal compounds not only solidifies and disperses strengthened copper bar alloys, but also reduces electrical conductivity little. This is an important alloying principle for the study of high-strength and high-conductivity alloys. It should be pointed out here that the alloys composed of iron, silicon, error, chromium and copper bar are very important high-strength and high-conductivity alloys. The influence of alloying elements on the properties of copper bars is superimposed, and the CoCr-Zr alloy is a famous high strength and high conductivity alloy.

(2) The structure of copper-based corrosion-resistant alloys should be single-phase, so as to avoid the electrochemical corrosion caused by the second phase in the alloys. For this reason, the alloying elements added should have great solid solubility in copper bars, even infinite mutual solubility. The single-phase brass bars, bronze bars and white copper bars used in engineering have excellent corrosion resistance and are important heat exchange materials.

(3) There are both soft and hard phases in the structure of copper-based wear-resistant alloys, so it is necessary to ensure that the added elements are not only solid soluble in copper bars, but also precipitated hard phases. The typical hard phases in copper-based wear-resistant alloys are Ni3Si and FeALSi compounds. In the automotive synchronizer gear alloys developed in recent years, phase A is soft and phase A is hard, and phase A should not be more than 10%.

(4) Copper rod alloys with polycrystalline transformation in solid state have damping properties, such as Cu-Mn alloys, and alloys with thermoelastic martensitic transformation in solid state have memory properties, such as Cu-Zn-Al and Cu-Al-Mn alloys. (5) The color of copper bars can be changed by adding alloying elements, such as zinc, aluminum, tin, nickel, etc. With the change of content, the color of copper bars also changes from red to blue to yellow and white. Reasonable control of the content will lead to gold-like materials and silver-like alloys.

(6) The elements selected for alloying copper rods and alloys should be common, cheap and pollution-free. The elements added should be in line with the principle of multiple elements and small amounts. Alloy raw materials can be used comprehensively. Alloys should have excellent technological properties and be suitable for processing into various finished and semi-finished products.