SHA Qing-yun
,
HUANG Guo-jian
,
GUAN Ju
,
MA Xiao-jun
,
LI Da-hang
钢铁研究学报(英文版)
The precipitates on austenite grain boundaries in an Nb-V-Ti microalloyed steel have been investigated by transmission electron microscope (TEM) examination of carbon extraction replica. The replica was prepared from specimen etched with saturated picric solution rather than Nital which is conventionally used. Then particles on both grain boundaries and triple point of grain boundaries were clearly observed and identified as (Nb,Ti)(C,N) particles. In case of conventional way, it is difficult to determine the location of particles with respect to austenite grain boundaries. The number of particles observed in new way developed was greatly reduced compared with that found in replica prepared by the conventional way, which may be caused by the dissolution of partial precipitates during the etching with longer time and at higher temperature involved in new way. Despite this, the new way developed provides an effective way to determine the precipitate particles on austenite grain boundaries.
关键词:
precipitate
,
austenite grain boundary
,
replica
,
etch
赵欣
,
李继定
,
陈剑
,
陈翠仙
膜科学与技术
doi:10.3969/j.issn.1007-8924.2003.06.003
在膜分离过程中,渗透物分子在聚合物膜内的扩散过程,是影响聚合物膜分离性能的关键因素.详细考察了目前被广泛使用的Vrentas-Duda扩散模型,对其进行改进,提出了新的计算ζ的公式.根据新提出的公式,对聚苯乙烯/甲苯(PS/toluene)、聚苯乙烯/乙苯(PS/ethylbenzene)、聚乙酸乙烯酯/甲苯(PVAc/toluene)3种体系中弱极性渗透物分子的扩散系数进行了预测,其较之原Vrentas-Duda扩散模型、Ju改进的Vrentas-Duda扩散模型有更好的预测结果.
关键词:
自由体积
,
扩散模型
,
聚合物膜
,
扩散系数
陈康
,
许希武
,
马凯
材料科学与工程学报
基于Ju和Chen提出的颗粒增强复合材料的一般细观力学方法,采用Qu给出的一阶近似修正的Eshelby张量,本文建立了考虑夹杂之间相互影响的含任意分布弱界面颗粒增强多相复合材料等效模量预测的一般细观力学方法,通过体积均匀化方法得到了一组细观力学本构方程.分别推导了忽略夹杂之间相互影响的弱界面多相复合材料宏观模量表达式以及考虑夹杂之间相互影响的弱界面两相复合材料的宏观模量表达式.此外,还给出了几种特殊复合材料体系在考虑界面弱化下的宏观等效性能参数的解析表达式,在界面粘结完好的假设下,给出的表达式均可以退化成经典的细观力学预测结果.在考虑夹杂之间相互影响的情况下,本文预测结果与实验数据吻合很好,验证了模型的有效性.
关键词:
夹杂之间相互影响
,
轻微弱化界面
,
细观力学
,
等效性能参数
,
颗粒增强复合材料
