摘要
Abstract
CuCr alloys have become the preferred contact materials in the field of environmentally friendly vacuum switches,and the research and development of efficient and high-performance homogeneous CuCr alloy preparation technology are at present a hotspot and a difficult problem in the research.In this paper the concepts of liquid phase sintering and copper infiltration are combined to prepare homogeneous CuCr alloys,and the solid solution and aging are used for secondary treatment so to observe the evolution of the microstructure and properties of CuCr alloys.It is found by the research that the homogeneous CuCr50 alloy can be stably prepared by the process of liquid-phase sin-tering coupled with infiltration of complementary copper,and the average particle sizes of the Cr-rich phase at the edge,middle and core of CuCr50 alloy are 48.35 μm,45.60 μm and 47.96 μm,respectively,the standard devia-tions of the Cr-rich phase particle sizes are in the range of 42.04-44.78 μm,and the homogeneity of microstructure after heat treatment(solid solution+aging)is verified further.The conductivity of the CuCr alloy is increased from 18.72-19.09 MS·m-1 to 22.62-22.93 MS·m-1,with an increase rate of 20.1%to 20.8%,and the tensile strength is in-creased from 308.76 MPa to 385.91 MPa,with an increase rate of 25.0%,which is attributed to the reduction of the solid-solution Cr content in the Cu-rich phase after heat treatment.These precipitated phases can exist in the alloy in the form of nanorods with function of diffusion strengthening which,on the one hand,improves the electrical con-ductivity of the alloy and,on the other hand,the precipitated phases impedes the dislocation slip,thus significantly improving the mechanical properties of the material.关键词
CuCr触头材料/液相烧结/熔渗补铜/热处理Key words
CuCr contact materials/liquid phase sintering/copper infiltration/heat treatment
