The University of Tokyo · 재료과학
Yoko Yamabe-Mitarai 교수의 연구실은 고온에서 안정적으로 기계적 변형을 복원할 수 있는 고온(shape memory) 합금, 특히 티타늄 기반의 희토류 금속 합금(예: Ti-Pt, Ti-Pd, Ti-Au)을 중심으로 연구를 진행하고 있습니다. 주요 연구 방향은 높은 전이 온도를 확보하면서도 강도와 복원 성능을 동시에 향상시키기 위한 합금 설계 및 상전이 거동 제어입니다. 또한 다성분 및 고엔트로피 합금을 활용한 신소재 개발을 통해 고온 구조재로서의 응용 가능성을 모색하고 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
To develop high-temperature shape memory alloys, Ti–50(Pt,Ir)mol% compounds are noted because of their martensitic transformation from B2 to B19(2H) or 4H(4O) structures above 1273 K. A thermal expansion measurement and loading-unloading compression test were performed for Ti–50(Pt,Ir) to determine if the shape memory effect or superelasticity was shown. The thermal expansion measurement indicated the shape recovery in some of the compounds. The maximum shape recovery was about 4% by reheating a
Rising martensitic transformation temperature is required to develop HTSMAs. Then, we have focused on the alloys consisting of Ti and precious metals such as TiPt, TiPd and TiAu due to their high martensitic transformation temperatures. To strengthen these compounds and control phase transformation temperature, third elements were partially substituted to the alloys. Some of the TiPd–base compounds indicated 100% shape recovery at temperature range between 400-450 °C. The effect of third element
In this paper high-temperature shape memory alloys based on TiPd and TiPt are reviewed. The effect of the alloying elements in ternary TiPd and TiPt alloys on phase transformation and strain recovery is also discussed. Generally, the addition of alloying elements decreases the martensitic transformation temperature and improves the strength of the martensite and austenite phases. Additionally, it also decreases irrecoverable strain, but without perfect recovery due to plastic deformation. With t
The temperature dependence of the strength of Ir3Nb with the L12 structure has been investigated using compression tests between -196 and 1200 degrees C. Below room temperature, the strength decreased with increasing temperature. An anomalous temperature dependence of the strength was observed between room temperature and 800 degrees C; the strength increased with increasing temperature. Above 800 degrees C, the strength again decreased with increasing temperature. The Burgers vectors of the dis
