本文選題：鎂合金　切入點(diǎn)：超疏水　出處：《蘭州交通大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

【摘要】：鎂及其合金具有比重輕,比剛度和比強(qiáng)度高,切削加工性能、導(dǎo)熱性能以及鑄造性能良好等一系列的優(yōu)點(diǎn),因此,鎂及鎂合金在交通運(yùn)輸、電子設(shè)備、汽車行業(yè)以及航空航天等領(lǐng)域均得到了廣泛的應(yīng)用。但是,因?yàn)殒V及其合金的耐腐蝕性能比較差,這就很大程度上影響了它的大規(guī)模使用。研究表明通過在材料表面構(gòu)建強(qiáng)疏水層,可以提高相關(guān)材料的耐腐蝕性能和表面自清潔性能�；诖�,本研究依據(jù)鎂的物理化學(xué)性質(zhì),采用了兩種過程簡單、成本低廉的制備方法構(gòu)建了超疏水鎂合金表面。與此同時(shí),研究了鎂合金表面的耐腐蝕性能及自清潔性能,主要研究內(nèi)容和結(jié)論如下:(1)通過鹽酸刻蝕、氨水浸泡和疏水長鏈接枝的方法,成功構(gòu)建得到接觸角達(dá)154.1°、滾動角為6°的超疏水鎂合金表面。利用接觸角測試、掃描電鏡觀察、紅外光譜分析、防黏附和電化學(xué)實(shí)驗(yàn)等分別對超疏水鎂合金表面的潤濕性能、表面微結(jié)構(gòu)和化學(xué)組成、防黏附行為和耐腐蝕性能進(jìn)行了考察。研究結(jié)果表明:鹽酸刻蝕和氨水浸泡使得鎂合金表面產(chǎn)生了微/納復(fù)合結(jié)構(gòu),而硬脂酸修飾使疏水烴基長鏈通過化學(xué)鍵接枝到具有微/納復(fù)合結(jié)構(gòu)的鎂合金表面。正是由于其特殊的表面微結(jié)構(gòu)和化學(xué)組成,使得超疏水鎂合金表現(xiàn)出了良好的防黏附行為和耐腐蝕性能。(2)通過水熱法在鎂合金表面成功構(gòu)建了一薄層超疏水膜,分別探討了反應(yīng)溫度、反應(yīng)時(shí)間、乙醇與水的體積比以及STA醇溶液濃度對鎂合金接觸角的影響。最后得出了最理想的反應(yīng)條件是:水熱法的反應(yīng)溫度為80 oC,在烘箱中的保溫時(shí)間為10 h,乙醇與水的體積比為1:1.4,硬脂酸乙醇溶液濃度為80 mmol/L。在最優(yōu)條件下制備得到的超疏水鎂合金的表面接觸角達(dá)到153.8°,滾動角為6°。利用電鏡照片觀察可知,通過水熱法處理之后,鎂合金表面構(gòu)建出了與基底牢固結(jié)合的原位生長的膜層,而且這些膜層由片狀的結(jié)構(gòu)錯落交替而成。(3)采用電化學(xué)測試和鹽水浸泡分別對兩種方法制備的超疏水鎂合金的耐腐蝕性能進(jìn)行研究。由電化學(xué)測試得到的Tafel曲線結(jié)果表明:超疏水促使鎂合金片的腐蝕電流密度數(shù)值變小而腐蝕電位數(shù)值增大。這表明鎂合金表面的超疏水膜層提高了材料的耐腐蝕性能。另外,我們將兩種方法所制備的超疏水狀態(tài)的鎂合金片和空白試樣放入鹽水溶液中浸泡,通過接觸角測試、EDS和XRD分析、SEM觀察對不同浸泡時(shí)間后試樣表面接觸角值、表面組成、相結(jié)構(gòu)和形貌變化進(jìn)行分析可知,相對于空白試樣,超疏水試樣有比較好的耐腐蝕性能。(4)超疏水鎂合金表面上的水珠在其表面滾動的時(shí)候,可以帶走鋪在表面的碳粉、煙灰、粉筆灰等污染物顆粒,這表明超疏水鎂合金表面也具有優(yōu)異的自清潔性能。
[Abstract]:Magnesium and its alloys have a series of advantages such as light specific gravity, high specific stiffness and specific strength, cutting and processing properties, thermal conductivity and good casting properties. Therefore, magnesium and magnesium alloys are used in transportation, electronic equipment, etc. The automotive industry, aerospace and other fields have been widely used. However, because of the poor corrosion resistance of magnesium and its alloys, The results show that the corrosion resistance and self-cleaning properties of the related materials can be improved by constructing a strong hydrophobic layer on the surface of the material. Based on this, this study is based on the physical and chemical properties of magnesium. The surface of superhydrophobic magnesium alloy was constructed by two simple and low cost preparation methods. At the same time, the corrosion resistance and self-cleaning property of magnesium alloy surface were studied. The main contents and conclusions are as follows: 1) etching by hydrochloric acid. The surface of superhydrophobic magnesium alloy with contact angle of 154.1 擄and rolling angle of 6 擄was successfully constructed by soaking in ammonia water and hydrophobic long linking branch. Contact angle test, scanning electron microscope observation and infrared spectroscopy were used to analyze the surface of superhydrophobic magnesium alloy. The wettability, microstructure and chemical composition of superhydrophobic magnesium alloy surface, such as adhesion resistance and electrochemical experiments, The adhesion behavior and corrosion resistance of magnesium alloy were investigated. The results showed that the microstructures / nanocomposites were formed on the surface of magnesium alloy by hydrochloric acid etching and ammonia immersion. The modification of stearic acid makes the hydrophobic alkyl long chain grafted to the surface of magnesium alloy with micro / nano composite structure by chemical bonding. It is precisely because of its special surface microstructure and chemical composition, The superhydrophobic magnesium alloy exhibits good adhesion behavior and corrosion resistance. (2) A thin layer of superhydrophobic film was successfully constructed on the surface of superhydrophobic magnesium alloy by hydrothermal method. The reaction temperature and reaction time were discussed respectively. The effect of the volume ratio of ethanol to water and the concentration of STA alcohol solution on the contact angle of magnesium alloy was obtained. The optimal reaction conditions were obtained as follows: the reaction temperature of hydrothermal method was 80 OC, the holding time in oven was 10 h, and the temperature of ethanol and water was 10 h. The volume ratio is 1: 1.4 and the concentration of stearic acid ethanol solution is 80 mmol / L. the surface contact angle and rolling angle of the superhydrophobic magnesium alloy prepared under the optimum conditions are 153.8 擄and 6 擄respectively. After hydrothermal treatment, the surface of magnesium alloy was formed by in situ growth, which was firmly bonded to the substrate. The corrosion resistance of superhydrophobic magnesium alloy prepared by electrochemical test and brine immersion was studied by electrochemical test and brine immersion respectively. The Tafel curve obtained from electrochemical test was obtained from the electrochemical test. The results show that superhydrophobicity can decrease the corrosion current density of magnesium alloy sheet and increase the corrosion potential value, which indicates that the superhydrophobic coating on magnesium alloy surface improves the corrosion resistance of magnesium alloy. The superhydrophobic magnesium alloy sheets and blank samples prepared by the two methods were immersed in brine solution. The surface contact angle and composition of the samples were observed by EDS and XRD analysis. The analysis of phase structure and morphology shows that the superhydrophobic sample has better corrosion resistance than the blank sample) when the water droplets on the surface of superhydrophobic magnesium alloy roll on its surface, it can take away the carbon powder and soot spread on the surface. The superhydrophobic magnesium alloy surface also has excellent self-cleaning properties, such as chalk ash and other contaminant particles.
【學(xué)位授予單位】：蘭州交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TG178

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 趙立強(qiáng);南泉;全貞蘭;吳杰;金花子;;溶膠-凝膠法制備超疏水表面的研究進(jìn)展[J];低溫與特氣;2015年05期

2 李軼;李慧中;姜俊;歐陽杰;;熱處理對AZ80鎂合金疲勞性能的影響[J];航空材料學(xué)報(bào);2014年06期

3 汪懷遠(yuǎn);孟e，

本文編號：1589378