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1、摘要鋁一石墨復(fù)合材料是一種理想的自潤(rùn)滑材料,非常適用于制造軸瓦、缸套等耐磨減摩零件。本文利用半固態(tài)鑄造技術(shù)制備了鋁一石墨復(fù)合材料,并對(duì)其微觀組織和摩擦性能進(jìn)行了研究,具體如下:1.利用半固態(tài)鑄造技術(shù)制各了組織均勻的鋁一石墨復(fù)合材料。借助于自行開(kāi)發(fā)的電磁一機(jī)械復(fù)合攪拌裝置制備了鋁一石墨半固態(tài)漿料并對(duì)其進(jìn)行了研究,得出了漿料固相率與攪拌溫度之間的線性關(guān)系:明確了鋁一石墨半固態(tài)鑄錠的漿料固相率與石墨顆粒聚集區(qū)尺寸之間的關(guān)系;獲得了消除鋁一石墨復(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30
2、%時(shí),能基本消除鋁一石墨復(fù)合材料中石墨的不均勻分布。2.采用銷(xiāo)盤(pán)摩擦磨損試驗(yàn)機(jī),在干摩擦條件下,對(duì)半固態(tài)鑄造的鋁一石墨復(fù)合材料與45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Ⅳ的關(guān)系,確定了它們之間的關(guān)系式為:∥=0.256+(1.157x10-4)Ⅳ+(8.749x10—7)Ⅳ2同時(shí),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間下摩擦表面的特征,確定了摩擦機(jī)理。結(jié)果表明,摩擦?xí)r問(wèn)在0-一40min階段,摩擦系數(shù)隨時(shí)間的延長(zhǎng),急劇下降;在40,-,120min階
3、段,隨著時(shí)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(shí)間變化,穩(wěn)定在0.2763左右。3.分析了在摩擦過(guò)程中石墨自潤(rùn)滑膜的形成機(jī)理,得出了摩擦系數(shù)的變化受摩擦表面石墨成膜過(guò)程的影響規(guī)律。關(guān)鍵詞:電磁一機(jī)械攪拌技術(shù);鋁.石墨復(fù)合材料;半固態(tài);摩擦分類號(hào):TB331;Tilll7.1ABSTRACTAluminum—graphitecompositeisaveryidealself-lubricatingandconductingwearablemateri
4、alforbearingandcylinderliner.Inthispaper,Aluminum—graphitecompositeispreparedbythesemi—solidcastingtechnology,itsmicrostructureandfrictionperformanceisstudied鷦follows:1.Theuniformaluminum-graphitecompositeispreparedbythesemi-solidcastingtechnology.Th
5、ealuminum-graphiteslurrywhichispreparedbytheelectromagnetic-mechanicalstirringtechnologyisresearched.ThelinearformulabetweenthesolidfractionandthestirringtemperatureWasattained;Therelationshipbetweenthesolidfractionandthesizeofaggregategraphiteisdete
6、rminedandtheconditionforeliminatingmacro-·segregationofgraphiteinthesolidAluminum··graphitecompositeisobtainedasfollows:whenthesolidfractionofthecompositeslurryisabove30%,themacro-segregationofgraphitecallbeeliminated.2.Frictionbehaviorofsemi·solidca
7、stingAluminum—graphitecompositeagainst45steelunderdryslidingisevaluatedinthepin-on—disctribologicaltester.TherelationshipbetweenfrictioncoefficientgandloadNisinvestigated,quadraticformulaisconcludedasfollows:∥=0.256+(1.157x10-4)Ⅳ+(8.749x10_7)Ⅳ2Therel
8、ationshipbetweenfrictioncoe伍cientandfrictiontimehavegot.Themicrostructurecharacteroffrictionsurfaceunderdifferentfrictiontimeisanalysedandthemechanismoffrictionisconfirmed.Theresultsshowthatwhenfrictiontimeiscontrolledbetweenm40minutes.frictioncoe伍ci