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BN/TiB_2纳米-微米复合粉末的制备及表征 总被引:1,自引:0,他引:1
利用化学溶液法,于酒精、水混合溶液中溶解分散H3BO3和CO(NH2)2,再加入TiB2,干燥后热处理合成了BN/TiB2纳米-微米复合粉末。通过差热-热重分析、X射线衍射和红外光谱分析,对合成产物进行了表征。结果表明:BN合成反应在700~1100℃之间完成,BN/TiB2复合粉末经1500℃热处理时,非晶态BN向h-BN转化。利用扫描电镜、透射电镜分析了粉体复合前后的形貌及显微结构特征,结果表明:BN包覆在TiB2颗粒表面获得了具有纳米-微米复合结构的BN/TiB2粉末。 相似文献
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A rapid-heating method in the absence of electric/magnetic field was achieved by introducing a self-propagating-combustion(SHS) as heating source. The effect of heating rate on the alumina grain growth was explored based on this rapid-heating method. Comparing with the alumina prepared by two different heating ratios(greater than 1 000 ℃/min in SHS and about 50 ℃/min in common pressureless sintering furnace), it was revealed that the rapid heating could promote the grain growth greatly without pressure during sintering. However, if a pressure was applied simultaneously, the grain growth would be almost completely restrained. Since these observations are quite different from the expectation, a new grain growth model was proposed. 相似文献
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