Study On The Effect Of Performances Of Cu-Ag Alloy By ECAP

ECAP(Equal Channel Angular Pressing)is a severe plastic deformation technology , which can effectively process bulk ultra-fine grains. Therefore, ECAP has recently attracted much attention from many researchers. Cu-Ag alloy is used as the contact wire of electrization railway, its strength and friction-wear properties have a important influence on its application. At the same time, ECAP can prove strength and friction-wear properties of Cu-Ag alloy.Cu-Ag alloy is carried out successfully to a total equivalent true strain of~3 by ECAP in C mean at room temperature. In the process of analysis and design, the upper bound theorem is used, the macroscopically mechanical model which is located in the corner of die is established in instance of having friction. The microstructure evolution and mechanical properties are investigated by means of optical microscopy (OM), scanning electron microscope (SEM), electronic tensile equipment and friction and wear machine. The main results are followed:In this paper, The method of calculation is chosen by the macroscopically mechanical model, and the extrusion force is calculated. Metallurgical structure is analyzed, the microstructure is fined, the evolution disciplines of microstructure in the X, Y and Z face is summarized. The results correspond with the theoretical analysis of the C mean. The properties are improved greatly after ECAP. The hardness is improved from 73.06 Hv to 131.63 Hv. The tensile strength is improved from 252.33MPa to 412.05MPa. The elongation is decreased much after ECAP, which decreases from 44.42% to 9.18% . The wear-resisting property is increased. The wear rate is decreased from 0.0923g/h to 0.0748g/h. By observing the Cu-Ag alloy friction surface and analyzing the abrasive dust by EDX, the mechanism of Cu-Ag alloy is adhesive wear, abrasive wear and oxidative wear. The wear-resisting property of Cu-Ag alloy is discussed. The influence of strength and hardness to wear-resisting property is analyzed. The improvement of strength and hardness is the reason for the improvement of wear-resisting property.