In-situ TEM Observation of γ→ε Martensitic Transformation during Tensile Straining in an Fe-Mn-Si Shape Memory Alloy

摘要

Through in -situ TEM observation on an Fe-30.3 mass/100Mn-6.1 mass/100Si shape memory alloy under extending at room temperature, it is found that on a lower applied stress level, the ε-martensite with γ-phase especially at those near by the stress- interfaces of pre-existing overlapped stacking faults or ε-martensite is growing by the motion of partial dis- concentrated locations e. g. inclusions. It is also observed that the ε-martensite is growing by the motion of partial dis- locations resulting in the widening and thickening of stacking faults until it is stopped by another martensite plate or grain boundary.