摘要
对粉末冶金法制备的20wt％SiO_2-Al-Mg复合材料的反应动力学进行了研究,发现反应时Al、Mg均匀同步地向颗粒内扩散,大部分Si被置换到颗粒外基体中。建立了SiO_2与Al-Mg反应的动力学模型,并总结出头30min颗粒SiO_2的反应层厚度与反应时间成抛物线关系,满足方程h^2=e^(6.36)t^(1.02),扩散系数A(C)=e^(6.36)=578.2(μm)~2s^1=5.78×10^(-6)cm^2s^(-1)其中扩散头10min满足方程h=3.84+9.13t。
Kinetics of 20wt %SiO2-Ai-Mg composites fabricated by powder metallurgy process was studied.
It was shown that during the reaction Al and Mg uniformly diffused from outside SiO2 particle to inside while Si which reduced from SiO2 diffused to outside.Kinetics model of reaction between particle SiO2 and Al-Mg was created.and it was found that in the first thirty minutes the relationship between conversion zone thickness of particle SiO2 and response time was parabolic,namely h2=e6036t1.02,with diffusion coefficient A (C) =e6.36=578.2(μm)2s = 5.78×106 em2s-1;but in the first ten minutes.the relationship was linear.namely h=3.84+9.13t
出处
《材料导报》
EI
CAS
CSCD
2003年第1期72-74,10,共4页
Materials Reports
基金
河北省自然科学基金(594084)
