【摘要】：顆粒增強銅基復合材料在保持良好導電、導熱性的前提下,能夠提高復合材料的強度、硬度等性能。顆粒增強相的種類有很多,而AlN具有高熔點、高硬度、熱膨脹系數(shù)小等特點,使得AlN增強銅基復合材料受到越來越多的人關(guān)注。本研究將Cu、Zr、AlN粉末按一定的比例稱取,通過行星式球磨機將粉末進行混合,對所制備的復合粉末進行XRD物相分析、SEM表面組織觀察以及粒度分析,研究不同球磨時間的Cu-Zr-AIN復合粉末性能。采用放電等離子燒結(jié)技術(shù)得到Cu-Zr-AIN復合材料,采用金相光學顯微鏡、掃描電子顯微鏡(SEM)和能譜儀(EDS)等對復合材料的微觀組織進行觀察分析,并探究了燒結(jié)溫度、AlN含量對Cu-Zr-AIN復合材料的致密度、抗壓強度、硬度、導電性以及摩擦磨損性能的影響。隨著球磨時間的延長,復合粉末的Cu、Zr的衍射峰強度降低,衍射峰不斷寬化,晶粒得到不斷細化。Cu-Zr-AIN復合粉末在球磨過程中,一部分Zr固溶到Cu中,形成銅鋯過飽和固溶體；球磨到20h后,出現(xiàn)新相Cu8Zr3,延長球磨時間,金屬間化合物衍射峰增強,新產(chǎn)生的金屬間化合物增多。AlN的衍射峰一直存在并且其衍射峰的強度變化不大,說明隨著球磨的進行,AlN與Cu粉末混合的更加均勻,但并未發(fā)生分解。在球磨過程中,球磨30h后,平均體積粒徑可達4.956um,繼續(xù)延長球磨時間復合粉末的粒度開始有所增加,粉末團聚加重。通過實驗分析,得出該復合粉末的最佳球磨時間為30小時。經(jīng)過放電等離子燒結(jié)得到的Cu-Zr-AIN復合材料,隨著燒結(jié)溫度的增加,Cu-Zr-AIN復合材料的致密度逐漸增加。燒結(jié)溫度在800℃時,復合材料的微觀組織均勻,燒結(jié)溫度高于800℃后,復合材料晶粒粗化,致密度增加緩慢。其顯微硬度和抗壓強度,在燒結(jié)溫度700℃到800℃范圍內(nèi),隨著燒結(jié)溫度的升高逐漸提高,燒結(jié)溫度升高到800℃以后,復合材料的顯微硬度和抗壓強度呈現(xiàn)下降趨勢。選取800℃為最佳燒結(jié)溫度。經(jīng)過放電等離子燒結(jié)所得到的復合材料,隨著AlN含量的增加,所得復合材料的密度、致密度和導電性能都不斷降低。而顯微硬度和抗壓強度都呈現(xiàn)出先增大后變小的變化趨勢。隨著AlN含量的增加,復合材料的摩擦系數(shù)先變小,然后增大。當AlN含量為5%時,摩擦系數(shù)出現(xiàn)明顯降低。當AlN含量超過5%后,復合材料摩擦系數(shù)逐漸增大。隨著AlN含量的增加,犁溝由深變淺,剝落的片狀組織減少,復合材料的磨損面變得平整,能夠延緩嚴重磨損的出現(xiàn)。本研究的意義在于探索放電等離子法制備Cu-Zr-AIN復合材料的工藝,以達到制備高強高導銅基復合材料的目的。
[Abstract]:Particle reinforced copper matrix composites can improve the strength and hardness of the composites under the premise of good conductivity and thermal conductivity. There are many kinds of particle reinforced phases, while AlN has the characteristics of high melting point, high hardness and low coefficient of thermal expansion, which makes AlN reinforced copper matrix composites attract more and more attention. In this study, the Cu,Zr,AlN powder was weighed according to a certain proportion, and the powder was mixed by a planetary ball mill. The surface microstructure and particle size of the prepared composite powder were analyzed by XRD. The properties of Cu-Zr-AIN composite powder with different milling time were studied. Cu-Zr-AIN composites were obtained by spark plasma sintering (SPS). The microstructure of the composites was observed and analyzed by optical microscope, scanning electron microscope (SEM) and energy spectrometer (EDS). The effects of sintering temperature and AlN content on the density, compressive strength, hardness, electrical conductivity and friction and wear properties of Cu-Zr-AIN composites were investigated. With the prolongation of milling time, the diffraction peak intensity of Cu,Zr decreases, the diffraction peak broadens, and the grain size of Cu-Zr-AIN composite powder is continuously refined. During ball milling, part of Zr is dissolved in Cu, forming copper-zirconium supersaturated solid solution. After ball milling for 20 h, the new phase Cu8Zr3, prolonged the milling time, the diffraction peak of intermetallic compound increased, and the diffraction peak of the newly produced intermetallic compound increased, and the intensity of the diffraction peak changed little. The results show that the mixture of AlN and Cu powder is more uniform with ball milling, but it does not decompose. During the milling process, after 30 hours of ball milling, the average volume particle size can reach 4.956 um.And the particle size of the composite powder increased and the agglomeration of the powder increased with the further prolongation of the milling time. Through experimental analysis, the optimum milling time of the composite powder is 30 hours. The density of Cu-Zr-AIN composites increased with the increase of sintering temperature. When the sintering temperature is 800 鈩，

本文編號：2218641