钛基高温形状记忆合金进展综述

Shape memory alloys have become important smart materials due to their unique shape memory effect and superelastic properties, showing great promising in aviation, aerospace, electronics, automotive and medical applications. The binary near-equiatomic nickel-titanium alloy is one of the most well-developed shape memory materials, but it is very difficult to be used at very high temperature (>100℃, 373 K). The high-temperature service environment represented by aviation, aerospace, nuclear reactors, etc. urgently requires shape memory alloy materials with high phase transformation temperature and good combined properties. Therefore, the development of high-temperature shape memory alloy has become a research focus and difficulty in this field. In recent years, researchers have used the new titanium-based alloys as research objects to obtain shape memory materials with high martensitic transformation temperature through the design of alloying elements, and developed new high-temperature shape memory alloy systems such as Ti-Ta based, Ti-Zr based, Ti-Nb based and Ti-Mo based alloys. On the basis of satisfying the high temperature phase transformation characteristics, these alloy systems exhibit different performance characteristics. For example, Ti-Ta based alloys can effectively inhibit the precipitation of ω phase by Ta element and improve the plasticity. Ti-Nb based alloys have good processing ability. In addition, the alloying elements such as Pd, Pt and Au can be used in alloys to further increase the phase transition temperature. The addition of elements such as Sn, Al, and Ga can appropriately lower the alloy transformation temperature and improve its mechanical properties and functional properties. In this paper, the research progresses of several high-temperature shape memory alloy systems such as Ti-Ta based, Ti-Zr based, Ti-Nb based and Ti-Mo basedalloys are reviewed. The effects of alloying elements on phase transformation temperature, shape memory effect and mechanical properties of alloys are analyzed. This paper gives comprehensive summary of the performance advantages and defects of various alloys, and proposes the development direction of new high temperature shape memory alloy materials in the future.