摘要
通过建立一套热-力-扩散全耦合方程并结合相场法模拟了固态烧结微结构演化,以研究烧结过程中驱动力与颈部生长的关系。计算结果表明,相对颈部半径与烧结时间遵循负幂指数关系,全耦合情况下,应变梯度耦合项起主要作用,温度梯度耦合项的影响较小;随着烧结颈部长大,颈部曲率迅速减小,烧结驱动力大幅降低。对比不同扩散迁移率下颈部相对半径的生长速率与烧结颈长驱动力关系曲线可以得出动力学方程,方程表明,颈部相对半径生长速率等于烧结颈长驱动力的k0次幂与扩散迁移率有关的物性参数CM之积。烧结颈长驱动力仅与颈部形态相关,与烧结速度和烧结历程无关。
A fully coupled thermo-mechano-diffusional phase field model was presented to investigate the relationship between the driving force and the neck growth during solid sintering.It could be seen from the morphological evolution that the neck radius will increases gradually and the neck curvature decreases with the interface migration in the sintering process.Moreover,with the decreasing of total surface area of the system,and the pores become circular and reduce gradually.The simulation results show that the strain gradient coupling term play a domain role in the fully-coupled condition,and the effect of the temperature gradient coupling term is negligible.Finally,dynamic equations can be obtained by contrastive analysis among the change of neck growth rates and driving forces of neck growth.It indicateds that the neck growth rate is the product of the neck growth driving forces to the power of k0 and the physical parameters CMwhich relates to the diffusion mobility.And the neck growth driving forces is only related to the shape of neck,and has nothing to do with sintering speed and sintering process.
作者
谭树林
张晓敏
赵志鹏
邬周志
TAN Shulin;ZHANG Xiaomin;ZHAO Zhipeng;WU Zhouzhi(College of Aerospace Engineering,Chongqing University,Chongqing 400044,China;Chongqing Key Laboratory of Heterogencous Material Mechanics,Chongqing 400044,China)
出处
《粉末冶金工业》
CAS
北大核心
2020年第6期15-20,共6页
Powder Metallurgy Industry
基金
国家自然科学基金资助项目(11872130)
重庆市自然科学基金面上项目(cstc2019jcyj-msxmX0084)。
关键词
固态烧结
热力扩散耦合
烧结驱动力
形态演化
相场模型
solid-phase sintering
thermo-mechano-diffusional coupled
diffusion driving force
morphological evolution
phase field method
