本文選題：h-BN + c-BN��； 參考：《哈爾濱工業(yè)大學(xué)》2015年碩士論文

【摘要】：本文將行星球磨后h-BN粉體進行熱壓燒結(jié),通過調(diào)節(jié)保溫時間和熱壓燒結(jié)的溫度,制得了不同晶粒尺寸的h-BN陶瓷。用h-BN和c-BN粉體分別和熔石英進行熱壓燒結(jié),制備了h-BN/Si O2和c-BN/Si O2復(fù)合材料。利用XRD、SEM等分析手段表征了材料的物相以及微觀形貌;利用萬能試驗機研究h-BN陶瓷的力學(xué)性能;通過離子濺射實驗,研究了h-BN陶瓷抗離子濺射性能,分析了濺射后材料表面的物相、粗糙度、微觀形貌的特征,并對材料的濺射機理進行了探索。研究表明,在保溫相同時間的條件下,隨著熱壓燒結(jié)溫度的提高,h-BN陶瓷的晶粒尺寸逐漸變大,從在1600oC保溫0.5h時的0.5μm增長到在1900oC保溫0.5h時的4μm。在燒結(jié)溫度相同的條件下,隨著保溫時間的增加,h-BN陶瓷的晶粒尺寸也逐漸增加,從在1800oC保溫1h的4μm增長到在1800oC保溫5h時的8μm。隨著h-BN陶瓷材料晶粒尺寸的增加,其抗彎強度有明顯的降低,其關(guān)系符合Hall-Petch公式。晶粒尺寸為0.5μm時h-BN陶瓷的彈性模量、抗彎強度和斷裂韌性最高,分別為50.1GPa、163.5MPa、和2.85 MPa?m1/2。在不同離子能量相同濺射時間和相同離子能量不同濺射時間的濺射條件下,h-BN陶瓷材料的抗離子濺射特性都隨著晶粒尺寸的增加而逐漸變差,表面粗糙度和濺射侵蝕速率隨晶粒尺寸的增加而逐漸增加。h-BN陶瓷的濺射侵蝕速率隨濺射時間增加而降低,但是隨著濺射能量的增加而增加。分別采用h-BN和c-BN粉體和熔石英為原料,熱壓燒結(jié)制備了不同晶型的BN/Si O2復(fù)合材料;隨濺射離子能量增加,濺射侵蝕速率逐漸增加;在相同離子能量條件下,隨濺射時間增加濺射侵蝕速率逐漸降低;h-BN/Si O2復(fù)合材料中h-BN晶粒比熔石英和方石英更容易被濺射掉,而c-BN/Si O2復(fù)合材料受濺射時,首先是包覆c-BN晶粒的熔石英被濺射掉,然后c-BN晶粒再由于脫粘而與熔石英基體發(fā)生分離,造成整體材料的濺射損失。
[Abstract]:In this paper, h-BN powders were hot-pressed and sintered after planetary ball milling. By adjusting the holding time and the sintering temperature, the h-BN ceramics with different grain sizes were prepared. The h-BN / SiO2 and c-BN / SiO2 composites were prepared by hot pressing sintering of h-BN and c-BN powders with fused quartz, respectively. The phase and microstructure of h-BN ceramics were characterized by XRDX SEM, the mechanical properties of h-BN ceramics were studied by universal testing machine, and the anti-ion sputtering properties of h-BN ceramics were studied by ion sputtering experiments. The surface phase, roughness and microstructure of the sputtering materials were analyzed, and the sputtering mechanism of the materials was explored. The results show that the grain size of h-BN ceramics increases gradually with the increase of sintering temperature, from 0.5 渭 m at 1600oC holding time to 4 渭 m at 1900oC holding 0.5h. At the same sintering temperature, the grain size of h-BN ceramics increased gradually with the increase of holding time, from 4 渭 m at 1800oC for 1h to 8 渭 m at 1800oC for 5h. With the increase of the grain size of h-BN ceramics, the bending strength of h-BN ceramics decreases obviously, and the relationship between them accords with the Hall-Petch formula. When the grain size is 0.5 渭 m, the elastic modulus, flexural strength and fracture toughness of h-BN ceramics are the highest, which are 50.1 GPA 163.5 MPa and 2.85 MPa / m 1 / 2, respectively. The sputtering resistance of h-BN ceramics becomes worse with the increase of grain size under the same sputtering time with different ion energy and different sputtering time with the same ion energy. The surface roughness and sputtering erosion rate increased with the increase of grain size. The sputtering erosion rate of H-BN ceramics decreased with the increase of sputtering time, but increased with the increase of sputtering energy. Using h-BN and c-BN powders and fused quartz as raw materials, different crystalline BN / Sio _ 2 composites were prepared by hot pressing sintering. The sputtering erosion rate increased gradually with the increase of sputtering ion energy, and at the same ion energy, With the increase of sputtering time, the erosion rate of h-BN / Sio _ 2 composites decreases gradually, and the h-BN grains are easier to be sputtered than fused quartz and cristobalite, while when c-BN / Sio _ 2 composites are sputtered, the fused quartz coated with c-BN grains is first sputtered off. Then the c-BN grain is separated from the fused quartz matrix due to debonding, resulting in the sputtering loss of the whole material.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TQ174.1

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本文編號：2034014