𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Effect of stress-induced martensitic transformation on the crack tip stress-intensity factor in Ni–Mn–Ga shape memory alloy

✍ Scribed by Feng Xiong; Yong Liu


Publisher
Elsevier Science
Year
2007
Tongue
English
Weight
565 KB
Volume
55
Category
Article
ISSN
1359-6454

No coin nor oath required. For personal study only.

✦ Synopsis


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 M s , 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.


📜 SIMILAR VOLUMES


Magnetic properties of stress-induced ma
✍ Oleg Heczko; Ladislav Straka 📂 Article 📅 2004 🏛 Elsevier Science 🌐 English ⚖ 98 KB

Thermoelastic and strain-induced martensitic transformations of single crystalline Ni 49.7 Mn 29.1 Ga 21.2 magnetic shape memory alloys were investigated by simultaneous detection of the strain and magnetization. The transformation temperature to austenite was T A = 314 K. The thermoelastic transfor

Effect of Si on the reversibility of str
✍ N. Stanford; D.P. Dunne 📂 Article 📅 2010 🏛 Elsevier Science 🌐 English ⚖ 695 KB

Fe-Mn-Si is a well-characterized ternary shape memory alloy. Research on this alloy has consistently shown that the addition of 5-6 wt.% Si is desirable to enhance the reversibility of stress-induced martensite vis-a `-vis shape memory. This paper examines the effect of Si on the morphology and the

Formation of stress-induced martensite i
✍ S. Stanciu; L.G. Bujoreanu 📂 Article 📅 2008 🏛 Elsevier Science 🌐 English ⚖ 853 KB

The structure of a Cu-13.67Al-4.28Ni-0.54Mn-0.14Fe (wt.%) shape memory alloy was analyzed in the initial condition, during a heating-cooling cycle, and during a room temperature loading-unloading mechanical cycle. A fully reversible martensitic transformation was revealed which was associated with a

Direct physical evidence for the back-tr
✍ S. Gollerthan; M.L. Young; K. Neuking; U. Ramamurty; G. Eggeler 📂 Article 📅 2009 🏛 Elsevier Science 🌐 English ⚖ 454 KB

Crack loading and crack extension in pseudoelastic binary NiTi shape memory alloy (SMA) miniature compact tension (CT) specimens with 50.7 at.% Ni (austenitic, pseudoelastic) was investigated using infrared (IR) thermography during in situ loading and unloading. IR thermographic measurements allow f