PDF《C09.先进陶瓷材料》

随着 M7 浓度增加,晶体形貌更趋近于球体;

所有浓度 M8 均为球体. 由表面张力测试结果可知,表面能在 48- 51mN/m 时为晶须形态,且长径比随表面能增大递增;

表面能在 33- 40mN/m 时为过渡形态,随表面能增大由球体向晶须态转变;

当表面能为

27 mN/m 时为球体. 固液界面能 γSL 对HAP 的影响主要是通过晶核自由能 ΔG*产生作用的.γSL 越高,G*越大,从而促进 c 面的生长,最 终生成晶须;

反之则抑制 c 面的生长,使晶须变短变宽,最终生长为长板片.

5 4. 结论 (1)通过改变模板剂的种类和浓度,可以有效实现对晶体形貌的控制. (2)模板剂通过对反应溶液表面能和界面能的改变,来影响晶体形貌. 关键词:羟基磷灰石;

均相沉淀法;

模板剂;

形貌;

表面能 C09-15 轨道交通制动系统用高性能碳纤维增强陶瓷基复合材料的研究 肖鹏,李杨,李专 中南大学粉末冶金研究院 As the rail transportation, for instance, Chinese high speed train, rapidly developed in the past decades, the high performance brake materials with excellent thermal resistance, light weight and reliable brake properties is be of urgent demand as replacements for metal brake disk. Carbon fiber perform reinforced dual matrix,carbon and SiC, composites (C/C-SiC) were prepared by a combined processes, namely, chemical vapor infiltration, then followed by liquid silicon infiltration. The microstructures, general physical properties, for instance, flexural, compressive, tensile strength and thermal behavior, tribological behaviors under some typical c........