Elastocaloric switching effect induced by reentrant martensitic transformation
Elastocaloric switching effect induced by reentrant martensitic transformation
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DOI：
10.1063/5.0007753
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发表时间：
2020-09-01
影响因子：
15
通讯作者：
Kainuma, Ryosuke
中科院分区：
文献类型：
--
作者：
Odaira, Takumi;Xu, Sheng;Kainuma, Ryosuke
蒸汽压缩技术广泛用于制冷、供暖和空调，消耗了全球能源的很大一部分。人们一直在努力提高效率以节约能源，并寻找新的制冷剂来取代具有高全球变暖潜能值的制冷剂。利用热材料的固态制冷被认为是一种高效、环保的制冷技术。其中，使用形状记忆合金的弹性热制冷由于其低的设备成本和对周围环境的要求较少而被评估为最有前途的一种。一般的热材料加热和冷却时，外部领域的应用和删除的热（传统的热效应），而少数材料显示相反的温度变化（逆热效应）。以前报道的形状记忆合金已被发现，无论是传统的或逆弹性热效应的潜热在单轴应力诱导马氏体相变。本文报道了一种自调节功能材料，它在Co-Cr-Al-Si Heusler型形状记忆合金中具有弹热开关效应。对于固定的合金成分，这些合金可以从传统的弹性热效应变为逆弹性热效应，因为环境温度的变化。这种独特的行为是由从常规马氏体相变到再入马氏体相变的潜热符号逆转引起的。弹性热开关效应的实现可以为固态制冷和温度传感器的系统设计开辟新的可能性。
Vapor compression technologies widely used for refrigeration, heating, and air-conditioning have consumed a large fraction of global energy. Efforts have been made to improve the efficiency to save the energy, and to search for new refrigerants to take the place of the ones with high global warming potentials. The solid-state refrigeration using caloric materials are regarded as high-efficiency and environmentally friendly technologies. Among them, the elastocaloric refrigeration using shape memory alloys has been evaluated as the most promising one due to its low device cost and less of a demand for an ambient environment. General caloric materials heat up and cool down when external fields are applied and removed adiabatically (conventional caloric effect), while a few materials show opposite temperature changes (inverse caloric effect). Previously reported shape memory alloys have been found to show either a conventional or an inverse elastocaloric effect by the latent heat during uniaxial-stress-induced martensitic transformation. In this paper, we report a self-regulating functional material whose behavior exhibits an elastocaloric switching effect in Co-Cr-Al-Si Heusler-type shape memory alloys. For a fixed alloy composition, these alloys can change from conventional to inverse elastocaloric effects because of the change in ambient temperature. This unique behavior is caused by the sign reversal of latent heat from conventional to the re-entrant martensitic transformation. The realization of the elastocaloric switching effect can open new possibilities of system design for solid-state refrigeration and temperature sensors.