添加Al对无压反应烧结制备Ti_3SiC_2粉末的影响

Effect of Al Addition on Synthesis of Ti_3SiC_2 Powder by Pressureless Reactive Sintering

为了研究添加少量Al对反应速度和产物纯度的影响，以Ti／Si／TiC／Al=2：2：3．5：x（x=0，0．05，0．1，0．15，0．20，0．25）的混合粉末为原料，在1100-1500℃用无压反应烧结方法制备了Ti3SiC2粉末。并用XRD、SEM及EDS对其进行分析。结果表明，添加适量的Al能加速Ti3SiC2粉末的合成，产物纯度显著增加，最高产物纯度可达99．37wt％，可以使获得单相Ti3SiC2粉末的烧结温度由1500℃降到1400℃。反应的机理在于Al能脱除体系中残留的氧，并且尽早形成液相，取代部分Si在M3AX2相中的位置，从而加速Ti3SiC2粉末的合成。

In order to research the effects of AI addition on the synthesis reaction and purity of the production, the Ti3SiC2 powder were prepared by pressureless reactive sintefing methods at 1100℃-1500℃ using Ti/SiFFiC/Al=2：2： 3.5 ：x （x=0,0.05,0.1,0.15,0.20,0.25） powder mixture as starting material, and Ti3SiC2 powder was analyzed by XRD, SEM and EDS. The results show that adding appropriate content Al can obviously accelerate the synthesis reaction, thus increase the purity of Ti3SiC2 powder up to 99.37wt%, and the feasible sintcring temperature decreases from 1500 ℃ to 1400 ℃, The reaction mechanism is believed to be that Al can deoxidize oxygen from the starting mixtures, and molten early in the reactants to substitute few Si in the MaAX2 phase, which accelerates the synthesis of Ti3SiC2 powder.