Study On Properties Of High-Strength And Wear-resistence Lead Bronze Alloy

In recent years,the study on the copper based alloys with high property have received much attention.It mainly because that the alloys possesses some supper properties,such as high strength,low friction coefficient and wear resistance.Along with deeper progress in research,nowadays,many sorts of wear resistance copper based alloys with different composition have been fabricated,which also with high strength,it includes tin bronze,aluminium,lead bronze,and so on.They have widely used in wear resistance parts such as bearing,bush,and so on.With tin bronze ZQSn6-6-3 and lead bronze ZQPb10-10 taken as a contrast,a new high-strength and wear-resistance lead bronze has been studied in this dissertation in order to prepare copper alloy with more excellent properties.New lead bronze was fabricated by melting methods which use pure copper,pure tin,nickel,brass,lead,and rare earth as materials.The alloy's mechanical property and wear properties were studied.The tensile strength of alloy had been tested by using the universal material testing machine,and the ring-block tribometer have been used to study the friction and wear behavior of the copper alloy in different load and sliding speed.The experimental results suggest that compared with ZQSn6-6-3 and ZQPb10-10,the new lead bronze shows higher strength.The addition of alloy elements such as tin,nickel,rare earth that is beneficial to the microstructure of the copper alloy,strengthening the copper matrix,and increasing the alloy's mechanical properties further.When under the same wear condition,the new lead bronze alloy shows the lowest friction coefficient than other two copper alloys,and the wear volume-loss of new lead bronze alloy is the lowest in the same wear time.Value of friction coefficient for new lead bronze decreases with the increase of lead content,it possesses minimum friction coefficient when the content of lead is 17%.The wear volume-loss of copper alloy is relevant to its hardness and the load,speed.The microstructure,composition, morphology of suface of copper based alloy have been extensively investigated by optical microscope(OM),scanning electron microscope(SEM),energy dispersive microanalysis(EDX) and other modern equipments.The results suggest that the distribution of lead which is soft particle in the copper matrix of lead bronze.Friction-reducing phase and the fined structure that is very helpful to the wear resistence of the copper alloy.Under oil-lubricared condition,when load is low,the dominant wear form is adhensive wear,with increase of load,the new lead bronze was dominated by serious adhesive wear,abrsive wear,and fatigue wear against steel.