Li WANG
,
Xiaobu HU
,
Xiangang XU
材料科学技术（英文）
High purity silicon carbide (SiC) powder was synthesized in-situ by chemical reaction between silicon and carbon powder. In order to ensure that the impurity concentration of the resulting SiC powder is suitable for high-resistivity SiC single crystal growth, the preparation technology of SiC powder is different from that of SiC ceramic. The influence of the shape and size of carbon particles on the morphology and phase composition of the obtained SiC powder were discussed. The phase composition and morphology of the products were investigated by X-ray diffraction, Raman microspectroscopy and scanning electron microscopy. The results show that the composition of resulting SiC by in-situ synthesis from Si/C mixture strongly depends on the nature of the carbon source, which corresponds to the particle size and shape, as well as the preparation temperature. In the experimental conditions, flake graphite is more suitable for the synthesis of SiC powder than activated carbon because of its relatively smaller particle size and flake shape, which make the conversion more complete. The major phase composition of the full conversion products is β-SiC, with traces of α-SiC. Glow discharge mass spectroscopy measurements indicated that SiC powder synthesized with this chemical reaction method can meet the purity demand for the growth of high-resistivity SiC single crystals.
关键词:
Activated carbon
,
null
,
null
,
null
,
null
刘海韬
,
程海峰
,
王军
,
唐耿平
,
周旺
,
郑文伟
稀有金属材料与工程
对PIP法制备2D-SiC_f/SiC复合材料成形浆料中惰性填料SiC含量对2D-SiC_f/SiC复合材料孔隙率、纤维体积分数以及力学性能影响进行研究.研究表明,SiC微粉含量较低时,浆料粘度过低,导致层间存在较大气孔,纤维体积分数不高,致使复合材料力学性能不佳,当SiC微粉含量过高时,浆料粘度过大,层间基体厚度增加,纤维体积分数下降,并且浸渍效率降低,孔隙率增大,复合材料力学性能下降.当SiC微粉含量为33.3%时,复合材料具有较低的孔隙率和较高的纤维体积分数,复合材料具有较好的力学性能,弯曲强度和断裂韧性分别达到211.7 MPa和8.56 MPa·m~(1/2).
关键词:
PIP工艺
,
SiC微粉
,
2D-SiC_f/SiC
,
力学性能
杨昱桢
,
向道平
,
何雨翔
材料导报
doi:10.11896/j.issn.1005-023X.2015.12.021
以光伏产业晶硅切割废砂浆为主要原料,通过真空碳化法制备了 SiC 粉末。在通过物理和化学方法测定废砂浆组分含量的基础上,确定了初始原料 Si/C 配比。随后,利用 XRD 和 SEM 分别研究了真空热处理温度、无机碳源种类等对所制备粉末的物相和组织的影响,产物粉末的粒径分布范围通过激光粒度仪测试。研究表明,在900~1100℃温度范围,随着反应温度的升高,硅粉与活性炭的碳化反应越来越完全,并在1100℃完全生成了 SiC 粉末。继续升温,X 射线衍射峰的强度逐渐升高,SiC 产物粉末的粒度越来越大。此外,不同碳源在相同条件的碳化反应结果表明,活性炭作为碳源比石墨效果更佳。
关键词:
晶硅废砂浆
,
真空碳化
,
SiC粉末
,
XRD
,
SEM
王永明
,
毕文娟
,
李家柱
,
殷军港
硅酸盐通报
本文建立了一种对SiC表面羟基浓度定量检测的方法,利用卡尔费休微量水分测定仪直接测量出SiC表面羟基浓度.经计算,本方法RSD为3.8％,对于SiC粉体表面羟基浓度测定能够得到满意的结果.通过X射线能谱仪(EDS)进行表面元素分析,表明酸碱处理使SiC粉体表面碳硅比趋向于符合化学式的1∶1.测量相同固相含量的SiC浆料粘度,数据表明经过酸碱处理过的SiC粉体使相同固相含量的浆料粘度降低.改变浆料的pH值可改变其粘度,找到了使SiC粉体流变性能最适宜的pH值.
关键词:
SiC粉体
,
卡尔费休微量水分测定仪
,
表面羟基
,
碳硅比
,
粘度
张宁
,
张天文
,
阚洪敏
,
王晓阳
,
龙海波
兵器材料科学与工程
为获得具有良好使用性能的碳化硅基陶瓷复合材料,以亚微米级SiC粉体和分析纯的Al(NO3)3与Y(NO3)3为主要实验原料、氨水为沉淀剂,用共沉淀包覆方法制备SiC-Al2O3-Y2O3纳米复合粉体,对复合粉体前驱体的DTA进行分析,并研究其在煅烧过程中的物相变化,以及煅烧温度对复合粉体的分散性和烧结性的影响.结果表明:Al2O3和Y2O3反应生成新相YAG,当YAG质量分数为10％、煅烧温度为600℃,复合粉体的烧结性能最好.
关键词:
亚微米级SiC粉体
,
SiC-Al2O3-Y2O3复合粉体
,
煅烧温度
