【摘要】 在合成SiC/FexSiy复合粉体的基础上,利用高温渗硅反应烧结制备工艺制得了SiC/FexSiy复合材料。研究了合成复合材料的关键工艺参数,确定最佳合成工艺参数为:炭黑配量5%,反应温度1550℃,恒温时间2h,FexSiy含量为5%的复合粉体。复合材料的最大常温抗折强度约为130MPa,且随烧结温度和材料中FexSiy相含量的变化而改变。SiC/FexSiy复合材料的抗折强度先随温度的升高而增加,直至转折温度Tm(900℃),然后随温度的升高而下降。材料的热导率随温度的升高而降低,在20~250℃下降迅速,之后下降幅度减缓。SiC/FexSiy复合材料的线膨胀系数随温度的升高而增加,800℃以后线膨胀系数变化幅度增大。更多还原

【Abstract】 After synthesizing SiC/FexSiy powders,composites were prepared by siliconizing reaction sintered at high temperature.The key technological parameters were researched.The optimal technological parameters were carbon black 5%,reaction temperature 1550℃,holding time 2h and FexSiy content 5%.The maximum rupture of composites is about 130MPa and varies with different FexSiy content.The rupture of SiC/FexSiy composites increased depending on elevating temperature and decreased after transition temperature Tm(900℃).The thermal conductivity of composites decreased depending on elevating temperature.From 20℃ to 250℃ thermal conductivity decreased rapidly and slowly after 250℃.The coefficient of linear expansion increased depending on elevating temperature and varied rapidly after 800℃.更多还原