高英俊罗志荣张少义黄创高
金属学报
doi:10.3724/SP.J.1037.2010.00216
针对Al-Ag合金溶质的Spinodal亚稳互溶隙曲线的特点, 考虑溶质场与析出相的相互作用,通过构造时效温度和溶质浓度相关联的局域相互作用自由能密度函数, 建立了低Ag溶质的Al-Ag合金析出过程的相场模型. 模拟了Ag溶质浓度分别为4.2%和22%的体系中溶质场的Spinodal分解和析出Guinier-Preston 区 (GPZ), 以及在析出相附近形成一种无沉淀区(PFZ)的演化过程. 模拟结果表明, 在析出相周围形成了 椭圆形的PFZ, 其宽度大约是棒宽度的2倍,而在远离PFZ的区域出现了由于Spinodal分解而形成的Ag溶质分布图案.经过足够长的时效时间, 溶质场析出GPZ. 当Ag溶质浓度较高时, 浓度场会在PFZ周围形成多条液滴状的平行流线环绕着的析出相. 模拟结果与实验观察结果很好地吻合.
关键词:
Al-Ag合金
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spinodal decomposition
,
phase–field simlation
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precipitation
Y.H. Xia 1)
,
T.P. Lou 1)
,
Z.T. Sui 1) and B. Li 2) 1) School of Material & Metallurgy
,
Northeastern University
,
Shenyang 110006
,
China 2) Jiamusi University
,
Jiamusi 154007
,
China
金属学报(英文版)
The fractal and spinodal decomposition models combined Monte Carlo method were used in computer simulation of phase separation from CaO MgO Fe 2O 3 Al 2O 3 SiO 2 glass. The fractal dimension was applied to quantitative analysis. The mechanism of phase separation was investigated. The results showed that the fractal dimensions and simulated micrographs of phase separation were in good agreement with the experimental results. And the mechanism of phase separation was spinodal decomposition.
关键词:
glass
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