本文選題：碳纖維布增強(qiáng)鋁基復(fù)合材料 + 真空熱壓擴(kuò)散法��； 參考：《南昌航空大學(xué)》2015年碩士論文

【摘要】：碳纖維增強(qiáng)鋁基復(fù)合材料具有比強(qiáng)度高、比模量高、導(dǎo)電導(dǎo)熱性能好和高溫強(qiáng)度穩(wěn)定等優(yōu)異特點(diǎn),在太空環(huán)境中,依然能穩(wěn)定的發(fā)揮其性能。本文選用純鋁箔和2024鋁合金為基體,表面無(wú)涂層的T300碳纖維布為增強(qiáng)體,采用真空熱壓擴(kuò)散法制備碳纖維布增強(qiáng)鋁基復(fù)合材料,系統(tǒng)研究了制備過(guò)程中模具內(nèi)溫度的溫度場(chǎng)分布,以及制備工藝參數(shù)對(duì)碳纖維布增強(qiáng)鋁基復(fù)合材料的微觀組織、界面結(jié)合、致密度、力學(xué)性能和斷口形貌等的影響規(guī)律。獲得主要結(jié)論如下。當(dāng)熱壓爐爐膛保溫在540℃-700℃范圍內(nèi),爐膛保溫在0-80min內(nèi),熱壓模具內(nèi)的溫度上升;爐膛保溫在80-120min內(nèi),模具的溫度場(chǎng)趨于穩(wěn)定,模具溫度上升緩慢,接近爐膛溫度;模具中心與距離模具中心50mm處的溫差低于3℃,熱壓模具中心的溫度比爐膛溫度低17℃。本文從爐膛保溫80min開(kāi)始計(jì)算熱壓時(shí)間,可以獲得穩(wěn)定熱壓溫度。模具中心溫度與爐膛保溫溫度及保溫時(shí)間關(guān)系的擬合方程為:4632T10388.500174.021.005.11149.250 tttt T-′-+-+-=模具中心爐膛距離模具中心50mm處的溫度與爐膛保溫溫度及保溫時(shí)間關(guān)系的擬合方程為:463250T1035.500167.0189.048.971.202 tttt Tmm-′-+-+-=距離模具中心爐膛熱壓溫度提高使鋁箔與鋁合金基體的流動(dòng)性增強(qiáng),熱壓溫度過(guò)高會(huì)使碳纖維束被灼燒受到損傷;熱壓時(shí)間的延長(zhǎng)使鋁箔與鋁合金基體向增強(qiáng)體碳纖維束之間擴(kuò)散時(shí)間延長(zhǎng),熱壓時(shí)間過(guò)長(zhǎng),導(dǎo)致制備周期變長(zhǎng),還會(huì)導(dǎo)致大量的Al4C3生成;熱壓壓力的增加克服鋁合金粉末之間的摩擦與相互楔住等外力,使復(fù)合材料中間的空氣外溢,熱壓壓力過(guò)大會(huì)使碳纖維束受到剪切力受到損傷。當(dāng)碳纖維布體積分?jǐn)?shù)為16.39%,在600℃,70min,15MPa工藝參數(shù)下制備出的復(fù)合材料結(jié)構(gòu)完整,致密度達(dá)到98.96%,鋁合金基體包裹著碳纖維束增強(qiáng)體,結(jié)合緊密,幾乎沒(méi)有孔隙。在600℃,70min,15MPa工藝參數(shù)下制備的復(fù)合材料,增強(qiáng)體碳纖維與鋁合金基體之間發(fā)生了微弱的化學(xué)反應(yīng),產(chǎn)生了極少量的Al4C3,在該工藝參數(shù)制備的復(fù)合材料的界面結(jié)合是混合結(jié)合界面,以溶解和潤(rùn)濕結(jié)合為主,機(jī)械結(jié)合和交換反應(yīng)為輔。隨著熱壓溫度的提高,熱壓時(shí)間的延長(zhǎng)和熱壓壓力的增加,碳纖維布增強(qiáng)鋁基復(fù)合材料的拉伸性能先升高,后降低。當(dāng)碳纖維布體積分?jǐn)?shù)為16.39%,在600℃,70min,15MPa工藝參數(shù)下,綜合性能最高,制備的復(fù)合材料試樣拉伸性能達(dá)123.92MPa。真空熱壓擴(kuò)散法制備的碳纖維布增強(qiáng)鋁基復(fù)合材料拉伸斷口分析表明,良好的結(jié)合界面在復(fù)合材料受力時(shí),通過(guò)界面脫黏與碳纖維束的拔出傳遞應(yīng)力,吸收斷裂能,提高復(fù)合材料的力學(xué)性能。
[Abstract]:Carbon fiber reinforced aluminum matrix composites have the advantages of high specific strength, high specific modulus, good thermal conductivity and high temperature strength stability. In this paper, pure aluminum foil and 2024 aluminum alloy were used as substrates, T300 carbon fiber sheet without coating was used as reinforcements, carbon fiber sheet reinforced aluminum matrix composites were prepared by vacuum hot pressing diffusion method. The temperature field distribution in the mould and the influence of preparation parameters on the microstructure, interfacial bonding, density, mechanical properties and fracture morphology of carbon fiber reinforced aluminum matrix composites were studied systematically. The main conclusions are as follows. When the furnace heat preservation of hot pressing furnace is in the range of 540 鈩，

本文編號(hào)：1779878