Effect of iron powder type on friction and wear properties of copper based friction powder metallurgy material

Abstract:The sintered copper based friction materials for high-speed train brake pads have a complex composition, which should possess good physical, mechanical and tribological properties in practical applications. In this paper, four kinds of friction materials were prepared by powder metallurgy technology and the effects of iron powders on the microstructural and tribological properties of copper based friction materials were characterized by scanning electron microscope (SEM) and X-Ray diffraction (XRD). The results showed that the iron powder as the enhanced component could effectively change the friction and wear properties of the experimental materials. The copper based friction materials containing hydroxy iron (1-5μm) have a relatively higher coefficient of friction, the friction coefficient was significantly improved by 16.8% compared with reduced iron under a rotation speed is 4000 r/min. The friction coefficient of friction material containing water atomized iron powder is relatively reliable with 3000-7000 r/min speed range. In the high speed environment, the friction surface of material containing reduced iron or hydroxy iron（1-5μm）mainly are cracks and brittle fractures, and the material containing hydroxy iron（10μm）or water atomized iron has obvious layered structure.Keywords: copper based friction materialsfriction and wearpowder metallurgyDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. Competing Interests:The authors have no relevant financial or non-financial interests to disclose.Additional informationFundingThis work was supported by Key Scientific and Technological Project of Henan Province (Grants No: 232102230055), the National Natural Science Foundation of China (Grants No: U1904175) and Postgraduate Education Reform and Quality Improvement Project of Henan Province (Grants No: YJS2022JD50).