本文選題：Cf/Al復合材料　切入點：顯微組織　出處：《哈爾濱工業(yè)大學》2015年碩士論文　論文類型：學位論文

【摘要】：本文通過擠壓鑄造法制備瀝青基Cf/Al復合材料,利用光學顯微鏡(OM)、掃描電鏡(SEM)、透射電鏡(TEM)、能譜儀(EDS)等儀器對復合材料和碳纖維的顯微組織進行觀察,對復合材料的熱物理性能和力學性能進行了測試。分析了不同種類的瀝青基碳纖維(K1100、P120和P100)以及不同的基體合金(1199、6063和5A06)對復合材料組織、熱物理性能和力學性能的影響。碳纖維表征結(jié)果說明:碳纖維石墨化度越高、微晶尺寸越大、片層越完整、片層取向性越高,其軸向熱導率越高。因此,瀝青基碳纖維P100、P120和K1100相較于PAN基纖維具有更高的軸向熱導率和彈性模量。復合材料界面結(jié)合良好,沒有碳化物Al4C3生成;當Mg元素含量較低時,Mg元素以置換固溶體的形式存在于鋁合金基體中;當Mg含量較低時,Mg元素以置換固溶體的形式存在于鋁合金基體中;當基體合金中加入的Mg含量達到6.5wt.%時,界面生成大量的Al3Mg2。瀝青基Cf/Al復合材料的縱向熱導率測試值在284.7 W/m K至417.7 W/m K之間,橫向熱導率在38.2 W/m K至98.3 W/m K之間。其中P100/6063復合材料的縱向熱導率高達390.7W/m K,與ROM模型吻合;而5A06為基體的復合材料在基體中固溶大量的Mg原子,使復合材料的熱導率降低。以1199和6063為基體的復合材料熱的縱向平均熱膨脹系數(shù)在-1×10-6/K至1×10-6/K范圍內(nèi),表現(xiàn)出低膨脹特性。而5A06基體的熱膨脹系數(shù)較高,使復合材料的縱向熱膨脹系數(shù)較高。溫度和碳纖維的種類對復合材料的橫向熱膨脹系數(shù)影響較小,20~100℃范圍內(nèi)平均熱膨脹系數(shù)在16×10-6/K至26×10-6/K之間,符合Kural-Min模型。復合材料的熱循環(huán)實驗結(jié)果表明:第一次循環(huán)過程出現(xiàn)開環(huán),這主要與復合材料中的殘余應力松弛有關(guān);且由于基體合金的塑性變形作用,在循環(huán)過程中出現(xiàn)了明顯的應變滯后環(huán)。以6063為基體的復合材料的彈性模量和抗彎強度較高,其中P120/6063復合材料的彈性模量和抗彎強度分別達到了496.4GPa和703MPa。斷口分析表明:復合材料主要以纖維拔出方式失效,通過適當合金化能有效減少碳纖維的拔出數(shù)量和拔出長度。
[Abstract]:In this paper, asphalt matrix Cf/Al composites were prepared by squeeze casting. The microstructure of the composites and carbon fibers were observed by means of optical microscope, scanning electron microscope, transmission electron microscope and energy spectrometer. The thermo-physical properties and mechanical properties of the composites were tested. The microstructure of the composites was analyzed by using different kinds of asphalt-based carbon fibers K1100P120 and P100) and different matrix alloys (11996063 and 5A06). The results of carbon fiber characterization show that the higher the graphitization degree of carbon fiber is, the larger the crystallite size is, the more complete the lamellar is, and the higher the orientation of the lamellar is, the higher the axial thermal conductivity is. Compared with PAN fiber, P100 / P120 and K1100 have higher axial thermal conductivity and modulus of elasticity. The interface of the composites is well bonded and no carbides are formed by Al4C3. When the mg content is low, the mg element exists in the aluminum alloy matrix in the form of replacement solid solution, when the mg content is low, the mg element exists in the aluminum alloy matrix in the form of the replacement solid solution, and when the mg content in the matrix alloy reaches 6.5 wt.%, A large amount of Al _ 3mg _ 2 was generated at the interface. The longitudinal thermal conductivity of the Cf/Al composites was between 284.7 W / m K and 417.7 W / m K, and the transverse thermal conductivity was between 38.2 W / m K and 98.3 W / m K. The longitudinal thermal conductivity of the P100 / 6063 composite was 390.7 W / m K, which was consistent with the ROM model. However, when 5A06 matrix composites dissolve a lot of mg atoms in the matrix, the thermal conductivity of the composites decreases. The longitudinal average thermal expansion coefficient of the composites with 1199 and 6063 matrix is from 1 脳 10 ~ (-6) / K to 1 脳 10 ~ (-6) / K, and the average thermal expansion coefficient of the composites is in the range of 1 脳 10 ~ (-6) / K to 1 脳 10 ~ (-6) / K. The thermal expansion coefficient of 5A06 matrix is higher than that of 5A06 matrix. The longitudinal thermal expansion coefficient of the composite is higher. The average thermal expansion coefficient of the composite is between 16 脳 10 ~ (-6) / K and 26 脳 10 ~ (-6) / K in the range of 20 鈩，

本文編號：1629239