کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1450651 | 988740 | 2007 | 9 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Effect of stress-induced martensitic transformation on the crack tip stress-intensity factor in Ni–Mn–Ga shape memory alloy Effect of stress-induced martensitic transformation on the crack tip stress-intensity factor in Ni–Mn–Ga shape memory alloy](/preview/png/1450651.png)
The Ni–Mn–Ga shape memory ferromagnetic shape memory alloys (FSMAs) are prone to fracture during thermal cycling. The present research shows that the primary reason for the thermally induced fracture of Ni–Mn–Ga FSMAs is the increase in the crack tip stress-intensity factor (SIF) due to stress redistribution around the crack tip as a result of stress-induced martensitic (SIM) transformation. On lowering the temperature to Ms, the crack tip SIF of Ni–Mn–Ga FSMA increases significantly, being very different from that of Ni–Ti and Cu–Al–Ni SMAs. The sensitive temperature dependence of crack tip SIF in Ni–Mn–Ga is responsible for its brittleness under thermal cycling. The temperature dependence of crack tip SIF is strongly related to the yield stress, the temperature dependence of the critical stress for SIM transformation and the transformation interval. Temperature rate also plays an important role in the fatigue behavior of Ni–Mn–Ga FSMAs under thermal cycling.
Journal: Acta Materialia - Volume 55, Issue 16, September 2007, Pages 5621–5629