文章信息/Info

Title:

Interface and the Preference of Transformation Crystallography

作者:

顧新福; 石章智; 陳冷; 楊平

（北京科技大學材料科學與工程學院，北京 100083）

Author(s):

GU Xinfu;  SHI Zhangzhi;  CHEN Leng;  YANG Ping

(School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China)

關鍵詞:

相變晶體學; 匹配/錯配; 界面; 位向關系; 計算軟件

Keywords:

transformation crystallography;  match/mismatch;  interface;  orientation relationship;  calculation software

分類號:

O799

DOI:

10.7502/j.issn.1674-3962.201810001

文獻標志碼:

A

摘要:

固態相變是調控材料微觀組織的一種重要手段。相變過程中，為了降低新相的形核能壘，新相與母相之間傾向于形成特定的位向關系，從而實現低能界面結構。兩相之間這種形成特定晶體學特征的現象被稱為相變晶體學擇優。與相變熱力學及相變動力學一樣，相變晶體學也是理解微觀組織形成不可缺少的知識。兩相界面結構是理解相變晶體學擇優規律的關鍵。由低能界面與界面匹配之間的關系出發，介紹了理解相變晶體學擇優規律的幾何模型及其應用。首先介紹匹配好區的定義，接著介紹定量描述匹配好區分布及界面位錯結構的O點陣理論，以及由O點陣理論衍生出的相變晶體學幾何模型和方法。相變晶體學模型輸入簡單，通常只需兩相晶格常數，即可輸出豐富的相變晶體學數據。最后以雙相不銹鋼中奧氏體析出相的相變晶體學為例，介紹了作者近年來開發的相變晶體學計算軟件PTCLab的應用。此外，介紹的方法原則上適用于晶界的分析。

Abstract:

Solid�瞭o�瞫olid phase transformation plays an important role in controlling microstructures in metallic materials. Specific orientation relationship (OR) and interfacial orientation (IO) are formed due to the reduction of the nucleation barrier via reducing the interfacial energy during phase transformation. The formation of such specific ORs and IOs is called the preference in transformation crystallography. In addition to phase transformation thermodynamics and kinetics, phase transformation crystallography is also indispensable for understanding the formation of various microstructures. Interfaces and their structures are the keys to understand the transformation crystallography. Specifically, interfacial matching is a common concept in geometric methods applied to study the crystallographic features generated from phase transformation. In this review, the method based on good matching sites (GMSs) in the interface is shown to qualitatively understand the transformation crystallography. The quantitative tool to describe the distribution of GMSs, i�眅. O�瞝attice theory, is reviewed thereafter. Geometrical methods based on O�瞝attice theory are further explored. Although the inputs for geometrical method are simple, usually needs lattice parameters of two phases during phase transformation, its outputs are rich in crystallographic features. Finally, a free software for transformation crystallography has been developed recently by us, PTCLab, is applied to understand the precipitation of austenite in duplex stainless steel. In principle, the concept reviewed in this paper could be also applicable to analyzing grain boundaries.