Landau theory of martensitic transformation in Fe-Mn-Si based alloys  

作　　者：Jianfeng Wan Shipu Chen Zuyao Xu 

机构地区：[1]Shanghai Jiao Tong Univ, Sch Mat Sci & Engn, Shanghai 200030, Peoples R China

出　　处：《Chinese Science Bulletin》2002年第5期430-433,共4页

基　　金：This work was financially supported by the National Natural Science Foundation of China (Grant No. 59671023);the Emerson Electric Corporation of U.S.A.

摘　　要：Considering the features of martensitic transformation in Fe-Mn-Si based alloys, the Landau theory is established by introducing the density of stacking faults as a new order parameter η and the corresponding free energy function. By using such an order parameter, the stacking fault mechanism of the nucleation and growth for the γ(fcc) →ε(hcp) martensitic transformation can be reasonably explained, and a further detailed mechanism is proposed. The stacking faults are generated and overlapped in an irregular form at the beginning and then becoming regular to create some transition structures till a stable phase forms at a certain temperature. The importance of the interface soliton is to complete the transformations into various structures of martensite but not the twinned one. The thermodynamics of fcc→hcp transformation and those between different transition structures are described by the free energy function established in the present note.Considering the features of martensitic transformation in Fe-Mn-Si based alloys, the Landau theory is established by introducing the density of stacking faults as a new order parameter η and the corresponding free energy function. By using such an order parameter, the stacking fault mechanism of the nucleation and growth for the γ(fcc) → ε (hcp) martensitic transformation can be reasonably explained, and a further detailed mechanism is proposed. The stacking faults are generated and overlapped in an irregular form at the beginning and then becoming regular to create some transition structures till a stable phase forms at a certain temperature. The importance of the interface soliton is to complete the transformations into various structures of martensite but not the twinned one. The thermodynamics of fcc→hcp transformation and those between different transition structures are described by the free energy function established in the present note.

关 键 词：order parameter density of STACKING fault LANDAU the-ory SOLITON FE-MN-SI ALLOYS mechanism of martensitic transforma-tion transition phase. 

分 类 号：TG142[一般工业技术—材料科学与工程]