Y. Okimori, T. Kawamura, T. Inamura, H. Hosoda, K. Wakashima, Tokyo Institute of Technology, Yokohama, Japan; S. Miyazaki, University of Tsukuba, Tsukuba, Japan
TiAu with B2-B19 martensitic transformation is a candidate as a high temperature shape memory alloy actuator due to its high actuation temperature around 900K and good oxidation and corrosion resistance expected due to its high Au content. Then, in order to clarify the high temperature shape memory properties, martensitic transformation temperature and mechanical properties were investigated for binary and ternary TiAu alloys. Martensitic transformation temperature was determined by differential scanning calorimetry measurements up to 1773K. It was found that one step martensitic transformation was recognized in all the alloys. The transformation temperatures identified are Ms=880K, Mf=863K, As=892K and Af=904K for Ti-50mol%Au, for example. By mechanical tests at high temperatures around 600-1000K, good shape recovery was confirmed for the binary and ternary alloys containing Fe, Co and Ni. Besides, in order to develop new high temperature actuator, a new composite based on TiAu was proposed and shape memory behavior of the composite was presented.
Summary: TiAu with B2-B19 martensitic transformation is a candidate as a high temperature shape memory alloy actuator due to its high actuation temperature around 900K and good oxidation and corrosion resistance expected due to its high Au content. Then, in order to clarify the high temperature shape memory properties, martensitic transformation temperature and mechanical properties were investigated for binary and ternary TiAu alloys. Martensitic transformation temperature was determined by differential scanning calorimetry measurements up to 1773K. It was found that one step martensitic transformation was recognized in all the alloys. The transformation temperatures identified are
Ms=880K,
Mf=863K,
As=892K and
Af=904K for Ti-50mol%Au, for example. By mechanical tests at high temperatures around 600-1000K, good shape recovery was confirmed for the binary and ternary alloys containing Fe, Co and Ni. Besides, in order to develop new high temperature actuator, a new composite based on TiAu was proposed and shape memory behavior of the composite was presented.
