Stability of Phases in SiC and Si_3N_4 Whisker Formation

• 作 者: 陈声崎 周延春 夏非
• 机 构: Institute of Metal Research Academia Sinica,Shenyang,110015,China,To whom correspondence should be a
• 出 处: Journal of Materials Science & Technology
• 发表日期: 1992年02期
• 关键词: nitride toughness easting length reinforced sintering defects ceram toward therm

The stability of the phases in equilibrium is calculated and discussed in order to analyse and predict thereactions in SiC and Si_3N_4 whisker formation.Equilibria among SiC,Si_3N_4,Si_2N_2O,SiO_2 and the gas phaseare evaluated at different C activity,N_2 pressure,and temperature.According to the phase stabilitydiagrams,Si_3N_4 whisker was formed with the increase of N_2 pressure and decrease of C activity;SiC whiskerwas stable with the increase of C activity and decrease of N_2 pressure.In order to control the impure phasesduring the whisker formation,O_2 partial pressure is the most important factor.

The stability of the phases in equilibrium is calculated and discussed in order to analyze and predict thereactions in SiC and Si_3N_4 whisker formation. Equilibria among SiC, Si_3N_4, Si_2N_2O, SiO_2 and the gas phaseare evaluated at different C activity, N_2 pressure, and temperature. Si3N4 whisker was formed with the increase of N_2 pressure and decrease of C activity; SiC whiskerwas stable with the increase of C activity and decrease of N_2 pressure.In order to control the impure phases of the whisker formation, O_2 partial pressure is the most important factor