本文選題：石墨烯　切入點：鎂基復合材料　出處：《沈陽理工大學》2017年碩士論文

【摘要】：石墨烯具有優(yōu)越的物理性能和機械性能,近年來被廣泛以增強體形式應用到聚合物基、陶瓷基和金屬基復合材料中。然而,少有文獻記載人們對石墨烯增強鎂基復合材料的研究,因此設計進行了石墨烯增強鎂基復合材料的相關實驗研究。首先,通過改進的Hummers法制備了單層或少層石墨烯,采用化學鍍銅法制備了鍍銅石墨烯。然后,采用球磨混料+冷壓+熱壓燒結工藝制備了石墨烯增強鎂基復合材料,利用金相顯微鏡、X射線衍射儀和掃描電鏡等檢測手段對材料的組織和成分進行表征和分析,并用維氏硬度計對它的硬度進行測試。最后,通過CASTEP第一性原理計算軟件對石墨烯-金屬復合界面進行計算,研究了不同界面的性能和結合強度。燒結溫度達到595℃時,制得的復合材料表面能夠保持清潔無裂紋,復合材料內部結合緊密,不容易發(fā)生潰散。1wt.%石墨烯能夠對鎂晶粒形成很好的包覆,在制得的復合材料內部晶界處石墨烯呈連續(xù)網(wǎng)狀分布,而石墨烯的添加量超過1wt.%時,過量的石墨烯容易在復合材料內部產(chǎn)生團聚,從而對復合材料的組織等因素產(chǎn)生不利影響。該石墨烯含量下的復合材料硬度能夠達到50HV,比鑄態(tài)和冷加工狀態(tài)下的純鎂分別提高了66.7%和38.9%。當混料時間達到12h時,復合材料的組織均勻性即可達到最大,持續(xù)增加混料時間,對組織均勻性改善的意義不明顯。通過軋制及熱處理,復合材料的組織能夠得到細化,而且隨著熱處理時間延長至3h,復合材料的組織均勻性得到改善。界面處石墨烯與銅基體存在強烈的相互作用,界面結合能達到4.79J·m-2,屬于化學結合,而石墨烯與鋁和鎂基體之間的相互作用較弱,界面結合能分別為1.415J·m-2和0.52J·m-2,屬于物理結合。通過對石墨烯表面鍍銅能夠改善石墨烯與鎂基體之間的潤濕性,使復合材料內部的界面結合得到增強。
[Abstract]:Graphene has been widely used in polymer, ceramic and metal matrix composites in recent years because of its excellent physical and mechanical properties.However, there are few studies on graphene reinforced magnesium matrix composites, so some experimental studies on graphene reinforced magnesium matrix composites have been carried out.Firstly, monolayer or less layer graphene was prepared by modified Hummers method, and copper-coated graphene was prepared by electroless copper plating.Then, graphene reinforced magnesium matrix composites were prepared by cold pressing and hot pressing sintering process. The microstructure and composition of the composites were characterized and analyzed by means of metallographic microscope X-ray diffraction and scanning electron microscopy.Its hardness was tested by Vickers hardness meter.Finally, the graphene / metal composite interface was calculated by CASTEP first-principle calculation software, and the properties and bonding strength of different interfaces were studied.When the sintering temperature reaches 595 鈩，

本文編號：1720703