(南京工程學(xué)院 材料工程學(xué)院 江蘇省先進(jìn)結(jié)構(gòu)材料與應(yīng)用技術(shù)重點(diǎn)實(shí)驗(yàn)室,南京 211167)
摘 要: 采用電化學(xué)加超聲剝離制取微納石墨烯片,通過(guò)粉末冶金制備石墨烯增強(qiáng)鋁合金。使用納米壓痕和摩擦磨損試驗(yàn)機(jī)對(duì)樣品的納米硬度、彈性模量、室溫蠕變以及摩擦性能進(jìn)行研究。結(jié)果表明:鋁合金的納米硬度和彈性模量隨著微納石墨烯片含量的增加呈線性提高;當(dāng)微納石墨烯片含量為0.20%(質(zhì)量分?jǐn)?shù))時(shí),石墨烯增強(qiáng)鋁合金的納米硬度和彈性模量比純鋁合金的分別提高66%和52%,室溫平均蠕變度在保載階段為純鋁合金的54.56%,在穩(wěn)定階段平均蠕變速率僅為純鋁合金的1/10,摩擦因數(shù)隨微納石墨烯片含量的增加而逐漸降低。微納石墨烯片的加入使得晶粒細(xì)化、產(chǎn)生高位錯(cuò)密度和晶格畸變,提高了石墨烯鋁合金復(fù)合材料的納米硬度以及彈性模量,微納石墨烯片對(duì)部分可動(dòng)位錯(cuò)釘扎提高了鋁合金抗蠕變性能,微納石墨烯片存在自潤(rùn)滑性提高了鋁合金摩擦性能。
關(guān)鍵字: 鋁合金;微納石墨烯片;電化學(xué);納米壓痕;室溫蠕變
(Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology, School of Material Science and Engineering, Nanjing Institute of Technology, Nanjing 211167, China)
Abstract:Graphene nanosheets (EG) were produced by electrochemical and ultrasonic method. Graphene aluminum alloy composites were prepared via powder metallurgy method. Nano-hardness, elasticity modulus, room temperature creep and tribological properties of the samples were investigated by using nano-indentation and friction wear testing machine, respectively. The nano-hardness and elasticity modulus increase linearly with the increase of EG content. When EG content is 0.20%, nano-hardness and elastic modulus of graphene aluminum alloy composite are 66% and 52% higher than those of aluminum alloy, respectively. The average creep degree of the aluminum alloy composites with 0.2% EG in holding stage is 54.56% of aluminum alloy, and the average creep rate of the aluminum alloy composites with 0.2% EG in steady-stage is only 1/10 of that of aluminum alloy. The friction coefficients of graphene aluminum alloy composites decrease with the increase of EG content. The nano-hardness and elasticity modulus of graphene aluminum alloy composites are enhanced through grain refinement, high dislocation density and lattice distortion. The creep resistance properties of graphene aluminum alloy composites are improved via EG pinning the movable dislocation. And the friction properties are improved because of the self-lubricating properties of the EG.
Key words: aluminum alloy; graphene nanosheets; electrochemical method; nano-indentation; room temperature creep


