球磨时间对放电等离子烧结合成Ti_3SiC_2纯度的影响

EFFECT OF BALL MILLING TIME ON THE PHASE PURITY OF Ti_3SiC_2 SYNTHESIZED BY SPARK PLASMA SINTERING

本文采用原料配比为3Ti/Si/2C/0.2Al(摩尔比)的单质混合粉体为原料,进行机械合金化(MA)和随后的放电等离子烧结(SPS),以制备高纯Ti3SiC2陶瓷,研究了球磨时间对放电等离子烧结制备Ti3SiC2的影响。结果表明,机械合金化混合粉体后,粉体颗粒明显细化。球磨10h,单质混合粉体会发生化学反应,生成TiC,Ti3SiC2混合粉体。继续球磨至20h,生成物混合粉体会显著细化。球磨时间对SPS烧结合成Ti3SiC2有显著的影响。球磨10h,即反应刚刚完毕,最有利于SPS合成致密高纯的Ti3SiC2,球磨时间较短(5h),对Ti3SiC2陶瓷的烧结促进作用不显著,而反应后继续延长球磨时间至20h,会降低烧结体中Ti3SiC2的纯度。采用球磨10h的粉体为原料,经850℃放电等离子烧结可获得纯度高达96%(质量分数,下同)的Ti3SiC2疏松块体,烧结温度提高到1100℃,可获得纯度为99.3%、相对密度高达98.9%的TiSiC致密块体。

3Ti/Si/2C/0.2Al mixture powder was used for fabrication of high purity Ti3SiC2 ceramic by mechanical alloying（MA）and spark plasma sintering（SPS）.Effect of ball milling time on fabrication Ti3SiC2 by SPS was investigated.The result shows that MA of mixed powder can obviously refine particlesige.After milling 10 h,in the mixed powder,TiC,Ti3SiC2 were synthesized by chemical reaction from Ti,Si and C.Milling for 20 h,the powder was refined.Ball milling time has a remarkable effect on SPS sintering synthesis of Ti3SiC2.Ball milling for 10 h.is good to accomplish reaction,and for synthesis of dense and high purity Ti3SiC2.Shorter milling time（5 h）had non-obvious effect.Over long（20 h）milling time decreased the Ti3SiC2 purity in the sinter.Ti3SiC2 with a purity of 96 wt% was obtained by MA for 10 h and subsequent SPS at 850℃.By sintering at 1 100℃,Ti3SiC2 with a purity of 99.3 wt% and a relative density of 98.9 was obtained.