本文關(guān)鍵詞： 碳納米管 鋁基復(fù)合材料 粉末熱軋 粉末冶金 力學(xué)性能 熱膨脹系數(shù) 預(yù)球磨　出處：《合肥工業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：碳納米管作為一維碳族材料,其具有的優(yōu)異的力學(xué)、電學(xué)、熱學(xué)等性能而被廣泛關(guān)注,同時(shí)它還具備高強(qiáng)度、高模量等特性作為優(yōu)良的復(fù)合材料增強(qiáng)相。利用碳納米管來增強(qiáng)鋁基體復(fù)合材料,探究復(fù)合材料的制備方法并對其相關(guān)性能進(jìn)行研究,對深入展開碳納米管對鋁基復(fù)合材料性能的改善,具有重要的價(jià)值和意義。本文通過粉末熱軋的工藝方法制備了碳納米管增強(qiáng)鋁基復(fù)合材料,利用連續(xù)熱軋的工藝,避免傳統(tǒng)粉末冶金工藝過程中間歇操作的不足,可以實(shí)現(xiàn)復(fù)合材料連續(xù)成型。研究了碳納米管的含量、結(jié)構(gòu)和復(fù)合粉體的球磨時(shí)間、轉(zhuǎn)速以及燒結(jié)溫度對碳納米管增強(qiáng)鋁基復(fù)合材料的影響。研究結(jié)果表明,軋制變形能減少復(fù)合材料內(nèi)部的組織間隙,改變鋁基體的晶粒取向,實(shí)現(xiàn)碳納米管在鋁基體中均勻分散。隨著碳納米管含量的增加,復(fù)合材料的密度和相對密度都不斷減小,復(fù)合材料的拉伸強(qiáng)度和硬度均是呈先上升后下降的變化趨勢,當(dāng)碳納米管質(zhì)量分?jǐn)?shù)含量為1.5%時(shí),其拉伸強(qiáng)度和硬度達(dá)到最大值,分別為298.23 MPa和93.33 HB,與相同工藝下制備的純鋁基體相比分別提高了約33.4%和15.4%。隨著溫度的升高,復(fù)合材料的熱膨脹系數(shù)逐漸增大,熱擴(kuò)散系數(shù)逐漸降低；隨著碳納米管含量的增加,復(fù)合材料的熱膨脹系數(shù)和熱擴(kuò)散系數(shù)均是逐漸降低。當(dāng)溫度為200℃,碳納米管的質(zhì)量分?jǐn)?shù)為2%的情況下,復(fù)合材料的熱膨脹系數(shù)為17.84×10-6K,與純鋁基體相比,下降了17.14%；復(fù)合材料的熱擴(kuò)散系數(shù)為37.036 mm2/s,相比與純鋁,降低了14.39%。利用預(yù)先球磨分散碳納米管與粉末冶金相結(jié)合的工藝,制備了碳納米管增強(qiáng)鋁基復(fù)合材料,研究了不同球磨轉(zhuǎn)速、球磨時(shí)間下的碳納米管的長徑比對復(fù)合材料的影響。研究結(jié)果表明,對碳納米管進(jìn)行預(yù)球磨處理能起到有效分散作用,隨著預(yù)球磨處理碳納米管的時(shí)間不斷增加,復(fù)合材料的拉伸強(qiáng)度和硬度均呈先增加后降低的變化趨勢,當(dāng)預(yù)球磨時(shí)間為150 min時(shí),復(fù)合材料的拉伸強(qiáng)度能達(dá)到243.35 MPa,硬度達(dá)到82.70 HB。當(dāng)預(yù)球磨碳納米管的轉(zhuǎn)速為400 r/min時(shí),用于增強(qiáng)復(fù)合材料的拉伸強(qiáng)度最佳,能達(dá)到279.73 MPa,復(fù)合材料的硬度能有78.64HB。
[Abstract]:Carbon nanotubes (CNTs), as one-dimensional carbon group materials, have attracted much attention due to their excellent mechanical, electrical, thermal and other properties. At the same time, they also have high strength. Carbon nanotubes (CNTs) were used to reinforce aluminum matrix composites. The preparation methods of composites were investigated and the related properties were studied. It is of great value and significance for further developing carbon nanotubes to improve the properties of aluminum matrix composites. In this paper, carbon nanotubes reinforced aluminum matrix composites were prepared by hot powder rolling. Continuous hot rolling was used to avoid the shortage of batch operation in the traditional powder metallurgy process, and the continuous forming of composite materials could be realized. The content, structure and milling time of composite powder were studied. The effect of rotating speed and sintering temperature on carbon nanotube reinforced aluminum matrix composites. The results show that rolling deformation can reduce the microstructure gap and change the grain orientation of aluminum matrix. Carbon nanotubes were dispersed uniformly in aluminum matrix. With the increase of carbon nanotube content, the density and relative density of composites decreased. The tensile strength and hardness of the composites increased first and then decreased. When the content of carbon nanotubes was 1.5, the tensile strength and hardness reached the maximum. It was 298.23 MPa and 93.33 HB. compared with the pure aluminum matrix prepared by the same technology, it increased about 33.4% and 15.44, respectively, with the increase of temperature. The thermal expansion coefficient of the composites increases and the thermal diffusion coefficient decreases gradually. With the increase of carbon nanotube content, the thermal expansion coefficient and thermal diffusion coefficient of the composites decrease gradually. When the temperature is 200 鈩，

本文編號(hào)：1478359