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以Ti,Si,TiC并添加Al的混合粉末为原料,采用机械活化辅助自蔓延合成法制备了Ti3SiC2粉末。研究表明,机械活化过程可将原料的粒度尺寸细化至10μm以下,反应物活性提高,并能激发自蔓延合成反应生成Ti-Si,SiC,TiCx等中间相。在上述条件下,合成单相Ti3SiC2粉末的温度可降至1350℃。反应机理为:Al作为脱氧剂通过抑制其它元素的氧化来促进主相的生成,且在反应物中优先熔化形成局部微小熔池,加速了反应物的扩散并生成TiCx和Ti5Si3中间相,从而促进Ti3SiC2粉末的生成。
Ti3SiC2 powder was prepared by mechanical activation assisted self-propagating synthesis using mixed powders of Ti, Si, TiC and Al as raw materials. The results show that the mechanical activation process can refine the size of raw materials below 10μm and increase the activity of reactants, and can stimulate the self-propagating synthesis reaction to form mesophases such as Ti-Si, SiC and TiCx. Under the above conditions, the temperature of the synthesized single-phase Ti3SiC2 powder can be reduced to 1350 ° C. The reaction mechanism is as follows: Al as a deoxidizer accelerates the formation of the main phase by inhibiting the oxidation of other elements, and preferentially melts in the reactants to form local micro-pools, accelerates the diffusion of the reactants and generates TiCx and Ti5Si3 mesophases, thereby promoting Ti3SiC2 powder formation.