本文選題：單晶金剛石 + 摩擦化學(xué)　； 參考：《大連理工大學(xué)》2015年碩士論文

【摘要】：金剛石在力學(xué)、熱學(xué)、光學(xué)、電學(xué)、聲學(xué)和化學(xué)穩(wěn)定性等方面有著無與倫比的優(yōu)異性質(zhì),使金剛石成為制作切削工具、半導(dǎo)體電子器件、高功率激光窗口、聲波濾波器和耐磨損涂層等元部件的理想材料。隨著金剛石合成技術(shù)的日臻完善,人造金剛石年產(chǎn)量早已超過46億克拉,各種性能得到開發(fā)利用。目前,人造金剛石在形狀和表面質(zhì)量無法直接滿足應(yīng)用要求,必須通過研磨或拋光,達(dá)到一定的表面粗糙度和面型精度后才能被使用,但單晶金剛石優(yōu)異的理化性質(zhì)使單晶金剛石加工制造工藝的難度很大。摩擦化學(xué)拋光技術(shù)既保證金剛石加工的效率與精度,又具有設(shè)備簡單價(jià)格低廉等方面優(yōu)勢,本文選擇該技術(shù)加工單晶金剛石,利用WMoCr拋光盤研究單晶金剛石的拋光工藝和相關(guān)理論,主要研究內(nèi)容和結(jié)論如下：(1)以機(jī)械合金化法制備的微細(xì)WMoCr合金粉末為原料,研究熱壓燒結(jié)參數(shù)對材料致密度和硬度的影響,并利用掃描電鏡(SEM)對材料的顯微組織進(jìn)行觀察。結(jié)果表明：機(jī)械合金化和熱壓固相燒結(jié)相結(jié)合的方法可以制備出的高致密度、高硬度的合金材料,在燒結(jié)溫度為1400℃、壓力為30 MPa、保溫時(shí)間為30 min的工藝條件下,所制備的WMoCr合金材料相對密度為96.49%,硬度為777.78 HV。(2)利用機(jī)械合金化和熱壓固相燒結(jié)制備的高性能的WMoCr合金盤,對單晶金剛石的摩擦化學(xué)拋光工藝進(jìn)行研究。在不同拋光壓力和速度下拋光20 min,考察金剛石的去除率和表面質(zhì)量、拋光盤的磨損量和氧化程度,制定出合理的拋光參數(shù)。結(jié)果表明：WMoCr拋光盤性能優(yōu)異,較低的拋光參數(shù)5.67 MPa和8.38 m/s下,獲得較高的金剛石去除率2.3 μm/min,同時(shí)較好的控制了金剛石表面質(zhì)量、拋光盤的磨損量和氧化等問題。(3)基于單晶金剛石表面形貌的分析,建立了金剛石表面微凸體的四棱臺(tái)結(jié)構(gòu)幾何模型,考慮拋光過程中材料特性和摩擦接觸情況,計(jì)算熱流密度、熱流分配系數(shù)和空氣對流系數(shù)等熱載荷。在拋光參數(shù)80N和8000 r/min下,利用ANSYS熱分析軟件對單晶金剛石摩擦化學(xué)拋光過程中的溫度場進(jìn)行仿真,仿真結(jié)果與實(shí)驗(yàn)測量結(jié)果基本相符。(4)通過對金剛石拋光背面測量溫度與其去除率關(guān)系的分析,得出金剛石拋光表面達(dá)到石墨化的臨界拋光參數(shù)6000 r/min和65 N,通過熱分析軟件ANSYS6對該拋光參數(shù)下金剛石溫度場進(jìn)行求解,計(jì)算出此時(shí)整個(gè)金剛石溫度分布范圍。結(jié)果表明：金剛石石墨化溫度的最低臨界值在624.5～658.1℃之間。
[Abstract]:Diamond has unparalleled excellent properties in mechanics, heat, optics, electricity, acoustics and chemical stability, making it a cutting tool, semiconductor electronic device, high power laser window, etc. Sound filter and wear-resistant coating and other components of the ideal material. With the improvement of diamond synthesis technology, the annual production of synthetic diamond has already exceeded 4.6 billion carats, and various properties have been developed and utilized. At present, artificial diamond can not meet the requirements of application directly in shape and surface quality. It must be ground or polished to achieve a certain surface roughness and surface precision before it can be used. However, the excellent physical and chemical properties of single crystal diamond make it very difficult to process and manufacture single crystal diamond. The tribochemical polishing technology not only guarantees the efficiency and precision of diamond machining, but also has the advantages of simple equipment and low price. In this paper, we choose this technology to process single crystal diamond. The polishing technology and related theory of single crystal diamond were studied by WMoCr polishing disc. The main research contents and conclusions are as follows: (1) the fine WMoCr alloy powder prepared by mechanical alloying method is used as raw material. The effect of hot pressing sintering parameters on the density and hardness of the materials was studied, and the microstructure of the materials was observed by scanning electron microscope (SEM). The results show that the high density and high hardness alloy materials can be prepared by the combination of mechanical alloying and hot pressing solid sintering under the conditions of sintering temperature of 1400 鈩，

本文編號(hào)：1898989