TiNbTaZr合金形变诱发马氏体的相变机制

Transformation mechanism of deformation-induced martensite in TiNbTaZr alloy

用透射电子显微镜对不同轧制变形量的Ti-28Nb-15Ta-4Zr合金进行观察分析。结果表明,该合金在轧制前为单相体心立方β相合金,在轧制变形过程中有形变诱发马氏体α″相形成,α″相为正交晶系,单胞参数a=0.3152 nm,b=0.4854 nm,c=0.4642 nm。β相与α″相的位向关系为[100]α″//[100]β,[010]α″//[01 1]β,[001]α″//[0 1-1-]β,(100)α″//(100)β,(010)α″//(01 1)β,(001)α″//(0 1-1-)β。据此提出形变诱发马氏体α″相变是以(0 1-1-)β为不变平面转变为(001)α″,在(100)β和(01 1)β面上原子经过微小迁移转变成(010)α″和(100)α″的马氏体相变机制。

Ti-28Nb-15Ta-4Zr alloy with different rolling deformation was characterized by transmission electron microscopy. The results indicate that the alloy shows bcc βsingle phase before rolling, and deformation-induced α＂ martensite is found during rolling deformation. The phase of α＂ martensite is orthorhombic system and its lattice parameters are a = 0. 3152 nm, b = 0. 4854 nm, c = 0. 4642 nm.Misorientation relationship betweenβ and α＂are [100]α^n//[]β,[010]α^n//[01 ]β,[001]α^n////[]β,（100）α^n//[ 00]β,（010）α^n//[01 ]β,（001）α^n//[0 ]β.The crystal plane （0 ）β being the habit plane transforms into （001）α＂ during transformation from β to α＂ phases, and martensite transformation mechanism is that the planes （ 00）β and （01 ）β transform to （010）α^n oand （100）α^n through tiny migration of atoms.