The future development direction of copper alloy materials

In recent years, with the improvement of people's awareness of environmental protection, environmental protection has become the theme of the development of world civilization. More attention has been paid to the influence of harmful elements such as lead, beryllium and arsenic. The development of environmentally friendly copper alloy materials such as lead-free cutting brass, beryllium-free copper alloy with high elasticity and arsenic-free copper alloy has become one of the important development directions of copper alloy materials.

There are two kinds of copper alloy materials: one is to introduce alloying elements to strengthen copper matrix to form alloy; The second is to introduce the second strengthening phase to form the composite material. For example, the dispersion-strengthened oxygen free copper is a typical artificial composite material, the commonly used dispersion particles are Al2O3, ZrO2, Y2O3, ThO2 and so on. Artificial composite material method refers to the material made by artificially adding particles, whiskers or fibers of the second phase to the copper matrix to strengthen the copper matrix, and by introducing evenly distributed, fine oxide particles with good thermal stability into the copper base to strengthen the copper. The composition of the second phase is usually below 1% or even lower to 0.01%, but it has obvious strengthening effect on the material, especially greatly improving the high temperature strength of the material. Such as Cu-2.5%TiB2(volume fraction), conductivity of 76%LACS, tensile strength of 675MPa; Cu-0.5%Al2O3(mass fraction) series alloy, the greenhouse strength of the material can reach 500~800MPa, the conductivity can reach 85%LACS above, the strength of the material can still reach 200~400MPa after burning hydrogen at 900℃.

Another type of rapid development is in situ composites (self-generated consistent materials), in situ composites refers to a kind of composite materials in the copper matrix, through the exothermic reaction between elements or between elements and compounds to generate reinforcement. The reinforcement in this kind of composite material has no interface contamination, and has good interface compatibility with the matrix. Compared with the traditional artificial external reinforcement composite material, its strength has been greatly improved, while maintaining good toughness and good high temperature performance. For example, the Cu-20%Nb(volume fraction) composite has a very high tensile strength, close to 2000Pa; The conductivity of cu-18% (mass fraction) is 66.6%LACS, and the tensile strength is 1450MPa. Other composite materials such as Cu-Fe and Cu-TA also have high strength at room temperature and high temperature, and the strength of the material can generally reach 800~1500MPa.