發(fā)布時間：2018-06-20 09:41

  本文選題：Ti_2AlN + TiN_x　； 參考：《北京交通大學(xué)》2017年碩士論文

【摘要】：針對目前Cu基復(fù)合材料應(yīng)用中高屈服強度高延展性的性能需求,本論文以Ti_2AlN陶瓷作為先驅(qū)體材料原位制備TiN_x顆粒增強Cu基復(fù)合材料,并研究了制備該體系材料存在的相關(guān)技術(shù)和科學(xué)問題。本文利用高溫下Ti_2AlN陶瓷與Cu的反應(yīng)行為,采用熱壓燒結(jié)法原位制備了TiN_x顆粒增強Cu基復(fù)合材料,通過X射線衍射(XRD)、掃描電鏡(SEM)、能譜分析(EDS)等手段研究了不同工藝下制備的復(fù)合材料的相組成及微觀結(jié)構(gòu)變化,測試了其力學(xué)性能,并初步探討了復(fù)合材料顯微結(jié)構(gòu)與性能之間的關(guān)系。研究結(jié)果表明:(1)在以Ti粉、A1粉和TiN粉為原料粉制備Ti_2AlN粉體時,原料粉三者的比例會對Ti_2AlN燒結(jié)純度產(chǎn)生一定的影響。在氬氣條件下,三者以1:1:0.95的比例在15℃/min的升溫速率下升溫至1450℃后保溫0.5h燒結(jié)出的Ti_2AlN粉體純度最高。(2)研究Ti_2AlN與Cu的反應(yīng)行為發(fā)現(xiàn),在1150℃,Ti_2AlN顆粒分解生成了TiN_x顆粒,而Al則進入基體Cu中形成Cu(Al)固溶體,TiN_x與Cu(Al)基體形成強結(jié)合界面。(3)以Ti_2AlN和Cu為原料在1150℃反應(yīng)燒結(jié)制備的TiN_x/Cu復(fù)合材料,微米尺度的Ti_2AlN顆粒分解為亞微米和納米級TiN_x顆粒,較均勻地分布于基體中。當(dāng)Ti_2AlN的體積含量為10%～40%時,復(fù)合材料中幾乎不存在Ti_2AlN,完全分解為TiN_x。(4)保溫時間和初始體積含量對TiN_x/Cu復(fù)合材料的顯微結(jié)構(gòu)有一定的影響。當(dāng)Ti_2AlN體積含量為30%時,TiN_x增強相顆粒的分布會隨保溫時間的增加而更加均勻地分布在基體內(nèi)。相同保溫時間下,TiN_x增強相顆粒隨著初始Ti_2AlN含量的增加而逐漸增多。(5)熱壓燒結(jié)制備的TiN_x/Cu復(fù)合材料具有良好的力學(xué)性能。對于初始Ti_2AlN體積含量為30%的TiN_x/Cu復(fù)合材料,保溫時間從0.5h增加至2h后,其抗壓強度和壓縮變形率分別從1060MPa和24.93%增加到1332MPa和38.68%;而抗彎強度從 630MPa 增加到了 785MPa。(6)隨著初始Ti_2AlN體積含量的增加,復(fù)合材料的密度降低,電阻率、維氏硬度、壓縮屈服強度和斷裂韌性增加。當(dāng)初始Ti_2AlN體積含量從10%增加到40%時,TiN_x/Cu復(fù)合材料的密度從8.25g/cm~3減小到7.31g/cm~3,維氏硬度從1.03GPa增加到3.03GPa,壓縮屈服強度從150MPa增加到625MPa,斷裂韌性由8.08MPa·m~(1/2)增加到 15.80MPa·m~(1/2)。
[Abstract]:In order to meet the requirement of high yield strength and ductility of Cu matrix composites, Ti2AlN ceramics were used as precursor materials to prepare TiNx particle reinforced Cu matrix composites in situ. The related technical and scientific problems in the preparation of the system were also studied. Based on the reaction behavior of Ti2AlN ceramics with Cu at high temperature, TiNx particle reinforced Cu matrix composites were prepared by hot pressing sintering in situ. The phase composition and microstructure of the composites prepared by different processes were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS), and the mechanical properties of the composites were tested. The relationship between microstructure and properties of composites was also discussed. The results show that when Ti powder Al powder and tin powder are used as raw materials to prepare Ti2AlN powder, the ratio of raw material powder to Ti2AlN powder will influence the sintering purity of Ti2AlN to some extent. In argon condition, Ti2AlN powders sintered at 15 鈩，

本文編號：2043827