Structure and properties of severely cold-rolled and annealed Ti–Ni shape memory alloys

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• 作者：S.D. Prokoshkin ; V. Brailovski ; K.E. Inaekyan ; V. Demers ; I.Yu. Khmelevskaya ; S.V. Dobatkin ; E.V. Tatyanin
• 关键词：Shape memory alloys ; Titanium nickelide ; Thermomechanical treatment ; Dislocation substructure ; Nanocrystalline structure ; Functional properties
• 刊名：Materials Science and Engineering: A
• 出版年：2008
• 出版时间：25 May 2008
• 年：2008
• 卷：481-482
• 期：Complete
• 页码：114-118
• 全文大小：434 K

文摘

The substructure and structure formation as well as the mechanical and functional properties of thermomechanically treated Ti–50.7 at. % Ni and Ti–50.0 at. % Ni alloys were studied using transmission electron microscopy and mechanical testing. A low-temperature thermomechanical treatment is carried out by rolling at room temperature in a true strain range e = 0.3–1.9. It is shown that the severe plastic deformation of Ti–Ni alloys results in a partial material amorphization and in the subsequent formation of a nanocrystalline austenite structure during post-deformation annealing. As a result, the completely recoverable strain and recovery stress become much higher than the values reachable using traditional low-temperature thermomechanical treatment with post-deformation annealing which creates a polygonized dislocation substructure.