添加铝对机械活化辅助合成Ti_3SiC_2粉末的影响(英文)

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。

EFFECT OF Al DOPING ON MECHANICAL ACTIVATION ASSISTED SYNTHESIS OF Ti3SiC2 POWDER

Ti3SiC2 powder was fabricated using Ti,Si and TiC mixed powders by the mechanical activation assisted self-propagating synthesis method with the aid of Al. It is found that the mechanical activation process can reduce particle size to less than 10 μm,promote reaction activity and induce self-propagating reaction to form intermediate phases. The powder with single Ti3SiC2 phase can be synthesized below 1 350 ℃ with the Al addition and mechanical activation. The reaction mechanism is believed to be that Al acts as deoxidizing agent to boost Ti3SiC2 main phase synthesis by inhibiting oxidation of other elements. In addition,Al melts first in the reactants to form local tiny molten baths,which accelerates the diffusion of the reactants to form TiCx and Ti5Si3 intermediate phases,thus promoting the synthesis of Ti3SiC2 powder subsequently.