本文選題：碳納米管 + 鑄造��； 參考：《南昌大學(xué)》2015年博士論文

【摘要】：碳納米管以優(yōu)異的物理化學(xué)性能在增強(qiáng)金屬基復(fù)合材料方面具有優(yōu)勢(shì),但如何將輕質(zhì)碳納米管添加進(jìn)鋼基體中一直是碳納米管復(fù)合材料領(lǐng)域的難點(diǎn)。本文探索了三種把碳納米管添加到鋼基體中的方法,最終確定使用鑄造沖入法將碳納米管植入鋼基體中,制備了鋼基碳納米管復(fù)合材料,研究了碳納米管對(duì)鋼的影響。對(duì)制備過程中涉及到的碳納米管分散,碳納米管與基體的結(jié)合,進(jìn)行了研究與分析,運(yùn)用掃描電鏡,透射電鏡以及拉伸試驗(yàn),金相分析等分析測(cè)試手段觀察分析了復(fù)合材料的組織結(jié)構(gòu),測(cè)試了復(fù)合材料的力學(xué)性能,對(duì)微觀組織結(jié)構(gòu)影響宏觀力學(xué)性能進(jìn)行了初步探討。首次發(fā)現(xiàn)碳納米管在澆注過程中形成了快速石墨化現(xiàn)象,對(duì)所發(fā)現(xiàn)筆直的石墨化碳納米管進(jìn)行了觀察和研究。先將碳納米管與鋁粉混合球磨,得到混合物后將其置于壓力機(jī)下制成餅狀預(yù)制塊,然后將這樣的預(yù)制塊粉碎并過篩得到粒度為2 mm的均勻顆粒,將此預(yù)制塊顆粒撒放在澆包底部,倒入1550℃鋼液,混合5s后澆入鑄型內(nèi)得到復(fù)合材料。對(duì)復(fù)合材料的力學(xué)性能進(jìn)行測(cè)試,發(fā)現(xiàn)碳納米管有助于提高復(fù)合材料的拉伸性能、硬度、摩擦磨損性能,其最優(yōu)加入量為：對(duì)于拉伸性能,加入量以0.04%最優(yōu)；對(duì)于硬度,加入量以0.01%最優(yōu)；對(duì)于摩擦系數(shù),加入量以0.04%最優(yōu)；對(duì)于磨損量,加入量以0.1%最優(yōu)。對(duì)復(fù)合材料的金相分析結(jié)果表明：碳納米管的添加對(duì)基體有著較為明顯的晶粒細(xì)化作用：隨著碳納米管加入量的增加,晶粒度水平有提高,在碳納米管加入量為0.1%時(shí)候效果最好,其后隨著碳納米管加入量增加,晶粒度水平降低；碳納米管的添加對(duì)晶粒度的影響是有方向性的。隨著碳納米管加入量的增加,基體在其中一個(gè)方向的晶粒度越來越高,在另一個(gè)方向上的影響不明顯。使用場(chǎng)發(fā)射掃描電鏡和高分辨透射電鏡對(duì)樣品進(jìn)行形貌分析。發(fā)現(xiàn)碳納米管與鋼形成“鋼筋混凝土式”加強(qiáng)結(jié)構(gòu),照片顯示鋼液能夠包裹碳納米管,從而形成加強(qiáng)結(jié)構(gòu),承擔(dān)外來載荷,使得復(fù)合材料的力學(xué)性能得以提高。發(fā)現(xiàn)筆直碳納米管。高分辨透射電鏡結(jié)果顯示筆直碳納米管管壁高度平行排列,這顯示碳納米管在澆注時(shí)在鋼液的催化作用下形成了快速而完全的石墨化。而這樣的筆直碳納米管使碳納米管分散問題得到完全解決成為可能。首次發(fā)現(xiàn)能在1550℃以下數(shù)十秒內(nèi)使碳納米管達(dá)到幾乎完全石墨化的程度。管壁高度平行排列顯示原始碳納米管內(nèi)部的缺陷被大量消除。以往的認(rèn)識(shí)認(rèn)為超過2200℃時(shí)石墨化較完全,且在2.5大氣壓下需要15mins,而在1800℃以下不能發(fā)生石墨化。相比以往的科學(xué)發(fā)現(xiàn),本實(shí)驗(yàn)的發(fā)現(xiàn)無論是在石墨化溫度以及石墨化速度都是一個(gè)科學(xué)突破。
[Abstract]:Carbon nanotubes (CNTs) have advantages in strengthening metal matrix composites with excellent physical and chemical properties, but how to add light carbon nanotubes into steel matrix has always been a difficult point in the field of carbon nanotubes composites. In this paper, three methods of adding carbon nanotubes (CNTs) to steel substrates were explored, and the effect of carbon nanotubes (CNTs) on steel was studied. The dispersion of carbon nanotubes and the bonding of carbon nanotubes with matrix were studied and analyzed. Scanning electron microscope, transmission electron microscope and tensile test were used. The microstructure and mechanical properties of the composites were observed and analyzed by means of metallographic analysis. The influence of microstructure on the macroscopic mechanical properties was preliminarily discussed. The rapid graphitization of carbon nanotubes (CNTs) was first found during the pouring process. The straight graphitized CNTs were observed and studied. The carbon nanotubes were milled with aluminum powder, and then the mixture was placed under the press to make the cake shape preform, and then the prefabricated blocks were crushed and sifted to obtain the uniform particle size of 2 mm. The prefabricated particles were sprayed at the bottom of the ladle and poured into the molten steel at 1550 鈩，

本文編號(hào)：1908123