Study On Friction And Wear Properties Of Copper-Molybdenum Disulfide Composite

Copper-based composite materials prepared by powder metallurgy have excellent physical and chemical properties,such as high specific strength,excellent heat resistance and wear resistance,small thermal expansion coefficient,and good dimensional stability.Therefore,copper-based composite materials can be used as brake friction materials in the aerospace,military and automotive industries.Molybdenum disulfide?MoS₂?is the most widely used solid lubricant due to its unique hexagonal layered structure.Adding MoS₂ to copper-based composite materials can reduce the amount of wear and improve friction and wear performance.So this article uses powder metallurgy method to prepare Cu-MoS₂ composite material.In recent years,how to improve the friction and wear properties and friction stability of materials by improving the preparation process and raw material system has been the focus of research.In this paper,the influence of the sintering process and MoS₂ content on the microstructure,hardness and friction and wear properties of the material was studied in contrast,and the friction and wear mechanism was discussed.The study found that when the sintering temperature reaches above 820?,Cu reacts with MoS₂ to form new compounds.Under the N₂+H₂ sintering atmosphere,copper sulfide and copper-molybdenum-sulfur compounds are mainly produced,while under Ar sintering atmosphere,only copper-molybdenum-sulfur compound.When the sintering atmosphere is constant,as the sintering temperature rises,due to the interfacial bonding of the sample and the influence of the generated compound,the friction coefficient gradually increases and the amount of wear gradually decreases.At 720?,the wear mechanism is mainly adhesive wear and abrasive wear.At 820?and 920?,the wear mechanism is mainly abrasive wear.When the sintering temperature is fixed,the microhardness of the samples sintered in the two atmospheres is not much different.However,due to the unique layered structure of cuprous sulfide,the friction coefficient and wear of samples sintered in Ar are larger than those sintered in N₂+H₂.The surface of the sample sintered in N₂+H₂ is smoother and the area of scars and flow marks is less.Next,the effect of MoS₂ content on the friction and wear properties of Cu-MoS₂composites was further explored.The results show that with the increase of MoS₂content,the continuity of matrix components decreases,and it is gradually distributed.The hardness of the composite increases first and then decreases,and the compressive strength gradually decreases.Has the best mechanical properties.After conducting friction and wear experiments,it was found that as the MoS₂ content increases,the friction coefficient of the composite material first decreases and then fluctuates within a certain range,while the wear rate of the composite material decreases first and then increases.Grain wear.When the MoS₂ content is 3%,the composite wear rate is the lowest and the wear morphology is also the smoothest.Therefore,the copper matrix composite with 3%MoS₂ added has the best tribological properties.