Shape memory behavior of Ti–20Zr–10Nb–5Al alloy subjected to annealing treatment

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• 作者：Zhi-Guo Yu ; Cheng-Yang Xiong ; Peng-Fei Xue ; Yan Li ; Bi-Fei Yuan ; Wen-Tao Qu
• 关键词：Ti–Zr ; Shape memory alloy ; Martensitic transformation ; Microstructure
• 刊名：Rare Metals
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：35
• 期：11
• 页码：831-835
• 全文大小：1,406 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Metallic Materials
  Chinese Library of Science
  
• 出版者：Journal Publishing Center of University of Science and Technology Beijing, in co-publication with Sp
• ISSN：1867-7185
• 卷排序：35

文摘

The effects of annealing temperature on microstructures, phase transformation, mechanical properties, and shape memory effect of Ti–20Zr–10Nb–5Al alloy were investigated. X-ray diffraction (XRD) patterns show that the alloy is composed of single hexagonal α′-martensite phase for both as-rolled sample and sample annealed at 773 K for 30 min, while single orthorhombic α″ phase exists in the samples annealed at 873 and 973 K for 30 min. The optical observations indicate that the alloy is recrystallized when annealed at 873 K, and the grain size of the sample annealed at 973 K is about five times larger than that annealed at 873 K. Both of the samples annealed at 873 and 973 K show almost the same reverse martensite transformation start temperature of 483 K as demonstrated by thermal dilatation tests. The critical stress values for martensite reorientation (σ_M) are 392 and 438 MPa for the alloys annealed at 873 and 973 K, respectively. The maximum shape memory strain is 2.8 %, which is obtained in the alloy annealed at 873 K due to the lower σ_M. Moreover, the sample annealed at 873 K exhibits larger tensile stress and tensile strain due to the smaller grain size.