Research On The Preparation And Performance Of Cu-Cr-Zr Composite Materials

Copper-matrix composites have not only high electrical conductivity but also high strength and temperature properties, so they are being applied to more industrial departments as electric, manufacturing, etc.In this paper, Cu-Cr-Zr composite powder was prepared by mechanical alloying(MA) firstly. The process characteristics, structural evolution and thermal stability of the MA Cu-Cr-Zr composite powders were investigated in detail by analyzing diffraction peak, crystalline size, lattice strain, lattice parameter and morphology changes of the composite powder during MA and subsequent annealing. Then hot-press sintering was used to prepare Cu-Cr-Zr composite materials, physical properties and mechanical properties were investigated. The effects of technological parameters of hot-press sintering on the microstructure and properties of Cu-Cr-Zr composite materials were studied. The conclusions are as follow:The results showed that stable supersaturated Cu(Cr) and Cu(Zr) solid solution formed after 70h milling of Cu-10%(Cr-Zr) and Cu-50%(Cr-Zr) composite powders. With the increasing of milling time, the diffraction peak intensity and grain size of composite powders were reduced, particles were gradually changed from flaky to sphere. After milling for 70h, particle size of Cu was about 15.861nm.When milling time was less than 30h, lattice parameter of Cu lattice strain were increased; when milling time was more than 50h, lattice parameter had been reduced, while the lattice strain would be recovered partially.Cu-10%(Cr-Zr) power reduced the lattice stain and internal strain, and increased the lattice ordering degree. Meanwhile, Cr and Zr precipitated from the supersaturated Cu(Cr), Cu(Zr) solid solution at the temperature of 500℃.Hot-press sintering was used to prepare Cu-10%(Cr-Zr) and Cu-50%(Cr-Zr) composite materials. Microstructure was formed by matrix phase, Cr phase and Cu-Zr composite phase. The results showed that intermetallic compound was Cu5Zr by analyzing TEM. With increasing sintering temperature, the density, hardness, conductivity and wear resistance were improved, while the bending strength was decreased. With the improvement of contents of Cr and Zr, just the hardness was increased, the other properties were reduced. Therefore, Cu-10%(Cr-Zr) composite materials has more better properties. In this paper, Cu-Cr-Zr composite powder was prepared by mechanical alloying and hot-press sintering. The best process parameters were found, the effects of Cu-Cr-Zr composite materials high content of Cr and Zr were studied. It is of great significances in theory and practice to develop the new type of copper matrix composites.