边-边匹配晶体学模型及其应用——HCP/FCC体系晶体学位向关系的预测

An Edge-to-Edge Matching Model and Its Application to the HCP/FCC System

应用“边-边匹配”晶体学模型，推导HCP／FCC体系中可能存在的各种晶体学位向关系．以αH／αF和cH／αH为变量，在一定的比值范围（αH／αF=0．7～1．2；cH／αH=1．5，1．6，1．7）和临界条件（晶向错配度低于10％，晶面错配度低于6％）下，得到HCP／FCC体系中8组可能出现的晶体学位向关系．最后，以Fe-Mn—Si合金为例，在具体的点阵常数下计算得到最可能的位向关系[112^-0]H／[110]F（0002）H／（11^-1）F，并通过透射电子显微分析测定了Fe-30Mn-6Si合金中面心立方结构（FCC）奥氏体和密排六方结构（HCP）马氏体的位向关系．实验测得的取向关系和用“边-边匹配”晶体学模型预测的晶体学取向关系吻合得很好，由此检验了该模型的正确性和实用性，也体现了其直观性的优点．

The edge-to-edge matching crystallographic model was used to predict all the possible crystallographic relationships between crystals that have hexagonal close packed （HCP） and face-center cubic （FCC） structures. Taking αH/αF and cH/αH as variables, while αH/αF varies from 0. 7-1. 2 and cH/αH 1.5, 1.6 and 1.7 respectively, eight groups of possible orientation relationship were obtained under the critical values （10% for interatomic spacing misfit and 6 % for interplanar distance）. Finally, based on the crystal structures and lattice parameters only, the model predicted the most possible orientation relationship of [11 20^-]H/[110]F（0002）F/（11^-1）F between face-center cubic（FCC） austenite and hexagonal close packed （HCP） martensite in Fe-Mn-Si alloy. The predicted orientation relationship agrees well with the experi- mental results observed by transmission electronic microscopy, which confirms and shows the preciseness, practicability and convenience of the model.