發(fā)布時(shí)間：2018-02-03 16:02

  本文關(guān)鍵詞： 碳納米管 混雜增強(qiáng) 鎂基復(fù)合材料 預(yù)分散 界面調(diào)控　出處：《哈爾濱工業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：本文研究了碳納米管(CNTs)機(jī)械球磨的預(yù)分散工藝,并對(duì)CNTs/Mg-6Zn復(fù)合材料的機(jī)械攪拌復(fù)合高能超聲波制備工藝進(jìn)行了探索。成功制備出增強(qiáng)體體積分?jǐn)?shù)不同的CNTs/Mg-6Zn和CNTs+Si C/Mg-6Zn復(fù)合材料,并對(duì)制備的鑄態(tài)復(fù)合材料進(jìn)行熱擠壓變形制備出擠壓態(tài)的復(fù)合材料。采用多種分析手段對(duì)復(fù)合材料的顯微組織進(jìn)行了研究,并對(duì)鑄態(tài)和擠壓態(tài)復(fù)合材料室溫拉伸性能進(jìn)行了測(cè)試,分析了顯微組織和力學(xué)性能的關(guān)系。通過加入Al元素調(diào)控碳納米管與鎂基體的界面結(jié)合。預(yù)分散工藝研究表明,將鋅粉和碳納米管混合機(jī)械球磨能夠打散原始碳納米管的團(tuán)聚,改善碳納米管的分散情況。球磨轉(zhuǎn)速及時(shí)間對(duì)碳納米管的分散都有一定的影響。當(dāng)球磨轉(zhuǎn)速為400rpm,球磨時(shí)間為4h時(shí),取得了最佳的碳納米管分散效果。將鋅粉、碳納米管和納米碳化硅顆�；旌锨蚰ツ芡瑫r(shí)分散納米碳化硅顆粒和碳納米管,有利于增強(qiáng)體進(jìn)一步在復(fù)合材料中的分布。探索出一種新型的制備碳納米管增強(qiáng)鎂基復(fù)合材料的液態(tài)制備法。首先將碳納米管和鋅粉進(jìn)行混合球磨對(duì)碳納米管進(jìn)行預(yù)分散。然后在半固態(tài)對(duì)基體合金進(jìn)行機(jī)械攪拌并加入增強(qiáng)體。之后在液態(tài)對(duì)復(fù)合材料進(jìn)行高能超聲處理。通過這三步逐漸的分散碳納米管制備出碳納米管在基體中分布彌散的鑄態(tài)鎂基復(fù)合材料。通過這種方法制備了質(zhì)量分?jǐn)?shù)分別為0.5%和1.0%的CNT/Mg-6Zn復(fù)合材料。碳納米管在基體中分布均勻,未見明顯的團(tuán)聚產(chǎn)生。碳納米管依然保持著其結(jié)構(gòu)完整性,經(jīng)過球磨、機(jī)械攪拌和高能處理后,通過透射觀察發(fā)現(xiàn)其管壁結(jié)構(gòu)依然非常完整。利用這種三步分散的液態(tài)制備法我們制備了新型的納米碳化硅顆�；祀s碳納米管增強(qiáng)Mg-6Zn復(fù)合材料。在球磨過程中,碳納米管與碳化硅顆�；ハ嗥鸬椒稚�(duì)方的作用。碳化硅顆粒的加入改變了基體合金中第二相的固溶度,析出了大量與鎂基體有特殊位相關(guān)系的棒狀第二相。當(dāng)碳化硅體積分?jǐn)?shù)為1.0%,碳納米管體積分?jǐn)?shù)為0.5%時(shí)復(fù)合材料的屈服強(qiáng)度和拉伸強(qiáng)度達(dá)到最高,分別為242MPa和318MPa。熱擠壓變形顯著細(xì)化了基體合金的晶粒,但是晶粒尺寸分布非常不均勻。熱擠壓改善了碳納米管的分布,使得碳納管沿?cái)D壓帶定向分布。在碳納米管的條帶中,晶粒尺寸非常細(xì)小表明碳納米管能夠組在再結(jié)晶晶粒的長(zhǎng)大。熱擠壓顯著提高合金和復(fù)合材料的力學(xué)性能。碳納米管的加入顯著細(xì)化了基體合金的晶粒,提高了擠壓態(tài)復(fù)合材料的強(qiáng)度,碳納米管的拔出和橋連增強(qiáng)作用提高了復(fù)合材料的額韌性。Al元素的加入旨在與復(fù)合材料中的碳納米管表面的無定向碳發(fā)生化學(xué)反應(yīng)在其界面處生成界面產(chǎn)物來改善復(fù)合材料與增強(qiáng)體之間的界面結(jié)合。通過透射觀察發(fā)現(xiàn)其界面處確實(shí)產(chǎn)生了一些細(xì)小的第二相。與此同時(shí),Al元素的加入改變了復(fù)合材料中第二相的固溶度,減少了其中第二相的析出。由于基體合金成分改變,碳納米管與基體潤(rùn)濕性得到改善,間接地提高了碳納米管與基體合金的界面結(jié)合,使復(fù)合材料的力學(xué)性能得到了顯著地的提高。
[Abstract]:This paper studies the carbon nanotube (CNTs) dispersion process of mechanical milling of CNTs/Mg-6Zn composites and pre mixing composite ultrasonic preparation technology was explored. Successfully prepared the volume fraction of different CNTs/Mg-6Zn and CNTs+Si C/Mg-6Zn composites, and the cast composites were prepared by composite the material extruded hot extrusion. By using kinds of analysis methods on the microstructure of the composite were studied, and the tensile properties of the cast and extruded state of composite material were tested, analyzed the relationship between the microstructure and mechanical properties. By combining the elements of Al regulation of carbon nanotubes with magnesium matrix pre dispersed interface. Experiments show that the new technology of zinc and carbon nanotube hybrid mechanical milling can break up original carbon nanotube agglomeration, improve dispersion of carbon nanotubes and the milling speed. Dispersion of carbon nanotubes have a certain impact. When the milling speed is 400rpm, ball milling time is 4h, the best dispersion of carbon nanotubes. The zinc powder, carbon nanotubes and nano SiC particles can be dispersed and mixed milling nano SiC particles and carbon nanotubes, is conducive to further enhance body distribution in composite materials. To explore a new preparation method of carbon nanotube reinforced liquid preparation of magnesium matrix composites. Firstly, carbon nanotubes and zinc powder mixing ball milling pretreatment on the dispersion of carbon nanotubes. Then in the semi solid state of matrix alloy mechanical stirring and adding reinforcement. After the high-energy ultrasonic treatment on the composite material in liquid through this three step gradually dispersed carbon nanotubes prepared by as cast magnesium matrix composite dispersed carbon nanotubes in the matrix prepared by this method. The mass fraction Don't CNT/Mg-6Zn composites with 0.5% and 1%. Carbon nanotubes uniformly distributed in the matrix, and there is no obvious agglomeration. Carbon nanotubes still maintains its structural integrity, after ball milling, mechanical agitation and high-energy treatment, observed by transmission structure of the tube wall is still very complete. By using the three step dispersion liquid the preparation method for our new nano SiC particles reinforced Mg-6Zn composite hybrid carbon nanotubes were synthesized. In the process of ball milling, carbon nanotubes and silicon carbide particles to disperse each other each other. The effect of SiC particles could change the solubility of the second phase of the matrix alloy, precipitated a lot with the magnesium matrix with special phase relationship between the rod of the second phase. When the SiC volume fraction is 1%, the volume fraction of the carbon nanotubes is 0.5% composite material yield strength and tensile strength reached the maximum, respectively 242MPa and 318M Pa. hot extrusion significantly refined grains of the matrix alloy, but the grain size distribution is very uneven. The hot extrusion can improve the distribution of carbon nanotubes, the carbon nano tube along the extrusion zone. Directional distribution in strip of carbon nanotubes, the grain size is very small that can grow up in the group of recrystallized grains of carbon nanotubes. Hot extrusion significantly improve the alloy and the mechanical properties of composite materials. The addition of carbon nanotubes significantly refines the grains of the matrix alloy, improve the strength of extruded composites, carbon nanotube pull-out and bridging enhancement effect to improve the toughness of.Al composite material, the elements added to the surface of carbon nanotubes in composite materials the non directional carbon chemical reaction on the interface generation interface products to improve the composite material and the interfacial bonding between the reinforcement. The interface was observed by transmission did produce The second phase of some small. At the same time, the addition of Al changed the solid solubility of the second phase in the composite, which reduces the second phase precipitation. The matrix alloy due to changes in composition, carbon nanotube and matrix wettability improved, indirectly increasing carbon nanotube and matrix alloy interface, the mechanical properties of composite the material has been significantly improved.

【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TB33;TQ127.11

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本文編號(hào)：1487788