資源描述:
《銅石墨復(fù)合材料的半固態(tài)制備及其摩擦性能研究》由會員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫。
1、韭瘟鑾適太生亟±堂焦j盆塞蟲奎擅噩中文摘要摘要:銅~石墨復(fù)合材料是一種理想的自潤滑、導(dǎo)電材料,是制各電力機(jī)車受電弓滑板等電接觸元件的理想材料。本文利用改進(jìn)機(jī)械攪拌技術(shù)制備了銅.石墨復(fù)合材料,并對其微觀組織和摩擦性能迸行了研究,具體如下:1.開發(fā)了改進(jìn)機(jī)械攪拌技術(shù),利用改進(jìn)機(jī)械攪拌裝置制備了組織均勻的銅一石墨復(fù)合材料。明確了銅一石墨半固態(tài)漿料的固相率與石墨顆粒聚集區(qū)尺寸之間的關(guān)系,獲得了消除銅一石墨復(fù)合材料石墨顆粒宏觀偏析的條件:當(dāng)半固態(tài)漿料的固相率大于40%時,能基本消除銅一石墨復(fù)合材料中石墨不均勻分布。2.采用銷盤摩擦磨損試驗(yàn)機(jī),在干摩擦條件下,對半固態(tài)鑄造的銅一石墨復(fù)合材料與4
2、5鋼組成的摩擦副進(jìn)行了摩擦性能研究,探索了摩擦系數(shù)與試樣承受載荷的關(guān)系,確定了它們之間的線性關(guān)系式為:∥=0.22641+(4.64952E一4)N。同時,明確了摩擦系數(shù)與摩擦?xí)r間之間的關(guān)系,揭示了在不同摩擦?xí)r問下摩擦表面的特征,確定了摩擦機(jī)理。結(jié)果表明,摩擦?xí)r間在0-40rain階段,摩擦系數(shù)隨時間的延長,急劇下降;在40~120min階段,隨著時間的增加,摩擦系數(shù)的下降趨于緩慢,只有小量的降低;而在120min之后,摩擦系數(shù)不隨時間變化,穩(wěn)定在0.3009左右。關(guān)鍵詞:改進(jìn)機(jī)械攪拌;銅一石墨;半固態(tài);摩擦jE基鑾壅盔堂亟主堂僮論塞△旦S!叢£工ABSTRACTCopper.gr
3、aphitecompositeisaveryidealself-lubricatingandconductingmaterialforelectriclocomotivepantographslideplate.Inthispaper,copper-graphiteslurryispreparedusingelectromagnetic-mechanicalstirringtechnology,itsmicrostructureandfrictionperformanceisstudiedasfollows.1.The—mechanicalstirringtechnologyisd
4、evelopedandthetmiformcooper-graphiteslurryispreparedbythistechnology.Therelationshipbetweenthesolidfractionandthesizeofaggregategraphiteisdeterminedandtheconditionforeliminatingmacro—segregationofgraphiteincopper-graphitecompositeisobtainedasfollows:whenthesolidfractionofthecompositeslurryisab
5、ove40%,themacro·segregationofgraphitecanbeeliminated.2.Frictionbehaviorofsemi·solidcastingcopper-graphitecompositeagainst45steelunderdryslidingisevaluatedinthepin·on-disctribologicaltester.Therelationshipbetweenfrictioncoefficientandloadisinvestigated,linearformulaisconcludedasfollows:∥=O.2264
6、1+(4.64952E·4)NTherelationshipbetweenfrictioncoefficientandfrictiontimeisgot.ThemicrostructurecharacteroffrictionsurfaceunderdifferentfrictiontimeisanalysedandthemechanismoffrictioniSconfirmed.TheresnltsshowthatwhenfrictiontimeiScontrolledbetween0--40minutes,frictioncoefficienttobogganastimeex
7、tends;ontheotherhand,whiletimeiscontrolledbetween40~120minutes,descendoffrictioncoefficientgoestObeslower,andonlyaliRledecliningisdoneARerthe120minutes,frictioncoefficienthasasteadyvalueofabout0.3009.withoutchangebytime.Keywords:mechani