考虑晶粒几何形状的尺度效应  

Scale Effect and the Geometric Shapes of Grains

作　　者：郭辉[1] 郭兴明[1] 

机构地区：[1]上海大学上海市应用数学和力学研究所,上海200072

出　　处：《应用数学和力学》2007年第2期127-134,共8页Applied Mathematics and Mechanics

基　　金：国家自然科学基金资助项目(10472061);上海市科委基础研究重点基金资助项目(04JC14034);教育部博士点基金资助项目(20060280015);上海市重点学科建设基金资助项目(Y0103)

摘　　要：复合材料方法中的混合律方法在研究纳米晶体材料力学性能时得到了广泛的使用,准确得出各相的体积分数对该方法结果的准确性具有十分重要的影响.将纳米晶体看成由晶界、晶粒和三叉晶三相组成的复合材料,根据晶粒具有多面体的几何特点,用二维的三相复合的正多边形模型来研究纳米晶体力学性能的尺度效应,对于不同几何形状的晶粒采用对应的正多边形模型,这样我们就可以更加准确地得到各相的体积分数,从而更好地预测纳米晶体材料的力学性能.The ＂rule-of-mixture＂ approach has become one of the widely spread ways to investigate the mechanical properties of nano-materials and nano-structures, and it is very important for the simulation results to exactly confute phase volume fractions. The nanocrystalline （NC） materials were treated as three-phase composites consisting of grain core phase, grain boundary （GB） phase and triple junction phase, and a two-dimensional three-phase mixture regular polygon model was established to investigate the scale effect of NC materials mechanical properties due to the geometrical polyhedron characteristics of crystal grain. For different multi-sides geometrical shapes of grains, the multi-sides regular polygon model was adopted to obtain more precise phase volume fractions and exactly predict the mechanical properties of NC materials.

关 键 词：纳米晶体 正多边形模型 屈服应力 体积分数 晶界 

分 类 号：TB383[一般工业技术—材料科学与工程] TG115.5[金属学及工艺—物理冶金]