γ(fcc)→ε(hcp)马氏体相变切变角计算的改进

The Improvement of Calculating γ(fcc)→ε(hcp) Martensitic Transformation Shear Angle

为了修正石玮等的模型在计算马氏体相变切变角时的局限性,给出对浮凸角的修正,从而得到正确的相变切变角.以Fe-25Mn-6Si-5Cr合金为例,用原子力显微镜测量了该合金应力诱发γ(fcc)→ε(hcp)马氏体相变的浮凸角,并在Thompson四面体和几何模型基础上,进一步结合Bergeon等关于浮凸角和切变方向位置关系模型,建立了一种更加普遍、有效的方法,由此修正了石玮等的局限性.用改进后的模型和计算方法得到的3个马氏体变体相变切变角计算结果,分别为20.80°、19.67°和19.73°,与相变切变角理论值19.47°符合得很好.

To correct the limitation of SHI et al ＇s method on calculating martensitic transformation shear angle and acquire right modification of surface relief angle, Fe-25Mn-6Si-5Cr alloy was taken as an example and its surface relief angles caused by stress-induced γ（fcc）→ε（hcp） transformation were measured by atomic force microscope. Then, based on the Thompson tetrahedron and geometry model, Bergeon et al ＇s model was introduced to improve the limitation of SHI et al ＇s method. The shear angles corresponding to the surface relief angles of three martensite variants were calculated to be 20. 80°,19. 67° and 19.73° respectively, which is in good agreement with the theoretical value 19.47°.