Surface Modification And Tribological Property Of Copper Alloy By Zirconium Ion Implantation

This study was aimed at non-reducing electrical conductivity and increasing surfacestrength, wear resistance of La₂O₃/Cu alloys, High-current Zr ion was implanted intocopper alloys, using a metal vapor vacuum arc (MEVVA) source at80keV ion energy andimplantation doses ranging from2×10¹⁷to1×10¹⁸Zr+/cm².The depth profile and chemical binding states of Cu2p,Zr3d and O1s in variousdepth of implanted layer were analyzed by X-ray photoelectron spectroscopy (XPS); Thedetail structure of the precipitated phases was observed by transmission electronmicroscope (TEM); the changes in microhardness of the modified surfaces were studiedby nano indentation measurements and the electrical conductivity was measured byphysical property measurement systems (PPMS); the wear resistance of the implanted andunimplanted material was studied with a ball-on-disc tribometer. The worn surfaces ofcopper alloys were analyzed by means of scanning electron microscope (SEM).The result revealed that there were Zr₂Cu, ZrO₂and Cu₂O precipitates formed in theimplanted layer after zirconium ion implantation. The Zr₂Cu phase dispersed in thesubstrate and its size is about10nm in diameter. With the increase of the implanting depth,the contents of ZrO₂, Cu₂O reduced gradually in the modified layer. And with the increaseof implantation dose, the content of Zr₂Cu increased, the depth in the maxium content ofZr2Cu was correspond to the maxium content of zirconium ion in the implantation layer.When the dose reached to1×10¹⁸Zr+/cm², the peak content of Zr2Cu was about12.23%(15nm in depth).Because of the formation of Zr2Cu, ZrO2and Cu2O phases, the hardness of thesubstrate enhanced markedly. And the hardness of the sample in ion dose of1×10¹⁸Zr+/cm²reached to4.51GPa which was4.3times greater than it in the substrate. With theincrease of implantation dose, conductivity became ruduced and maxium decrement wasless than8%.The mainly reason of the improvement of the wear resistance was the enhancementof the hardness in substrate after zirconium ion implantation.and with the increase of dose,the duration in lower friction coefficient condition prolonged. The wear mass increased with the increase of load and sliding speed, while decreased with the increase of ion dose.