Study On The Tribological Properties Of Copper-Nickel And Copper-Lead Bearing Materials

With the rapid development of the automotive industry and people’s increased awareness of environmental protection, copper-based bearing materials are required to have better performance. Hope them not only realise lead-free, but alao has high load capacity, anti-fatigue properties, fine corrosion-resistant and heat-resistant abiliities. Lead-free copper-nickel based alloys have advantages used as elastic materials instead of beryllium bronze, also they have some potential on the aspect of heat resistance and corrosion resistance when used as anti-friction and wear-resistant materials. Lead-free copper-nickel, copper-lead bimetal bearing materials were prepared by the powder metallurgy method. The heat resistance, corrosion resistance and tribological properties were studied by means of many microscopic analysis, the mechanisms were alao analyzed.The lead-free copper-nickel bearing material has obvious age hardening phenomenon, the hardness reaches the highest after 400 ℃ heat treatment and always larger than the two copper-lead materials and also has good heat resistance. The friction and wear performances of lead-free copper-nickel bearing material was tested by using the HDM-20 tribometer,and was compared with the typical copper-lead bearing materials.The results showed that the tribological properties of lead-free copper-nickel bearing material was close to the typical copper-lead bearing materials under the condition of low load and abundant lubrication,but the running-in property was a bit poor, and obviously influenced by load and speed. Its friction pair firstly occurred damage, and the anti-friction and anti-adhesion capacities were not as good as copper-lead materials which soft lead phase can gradually formed a protective film in the surface and worked together with the lubricating oil under the condition of gradual loading oil lubrication. There had many pores on the surface of lead-free copper-nickel bearing material, but the surface pores of two kinds of copper-lead materials were filled with lead element.So under the presoaked oil condition,its tribological performances were better than that of the copper-lead materials. In the process of deteriorated oil corrosion,the surface of lead-free copper-nickel bearing material formed a layer of protective oxide film which can prevent matrix further destruction,so it had better corrosion resistance.The matrix structure of copper-lead materials were severely damaged and the friction and wear properties were obviously reduced due to the lead element was selectively corroded and dissolved.