Effect of Sn Content on the Microstructural Features, Martensitic Transformation and Mechanical Properties in Ti-V-Al-Based Shape Memory Alloys  

作　　者：Xiao-Yang Yi Wei Liu Yun-Fei Wang Bo-Wen Huang Xin-Jian Cao Kui-Shan Sun Xiao Liu Xiang-Long Meng Zhi-Yong Gao Hai-Zhen Wang 

机构地区：[1]Department of Nuclear Equipment,College of Nuclear Equipment and Nuclear Engineering,Yantai University,Yantai,264005,China [2]School of Materials Science and Engineering,Harbin Institute of Technology,Harbin,150001,China [3]Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing,Yantai,264005,China

出　　处：《Acta Metallurgica Sinica(English Letters)》2023年第8期1247-1260,共14页金属学报（英文版）

基　　金：financial support from the National Natural Science Foundation of China(Nos.52101231,52101232 and 51871079);the Science Fund of Shandong Laboratory of Advanced Materials and Green Manufacturing(Yantai)(No.AMGM2021F09);the Natural Science Foundation of Shandong Province,China(No.ZR2021QE044);the Gansu Province Science and Technology Foundation for Youths(No.21JR7RA088).

摘　　要：In the present study, it is expected to tailor the microstructural features, martensitic transformation temperatures and mechanical properties of Ti-V-Al shape memory alloys through adding Sn alloying elements, which further expands their applications. Sn addition results in the monotonous rising of average valence electron number (e/a). In proportion, the single α″ martensite phase directly evolves into merely β parent phase in present Ti-V-Al-based shape memory alloys, as Sn content increases from 0.5 to 5.0 at.%. Meanwhile, Sn addition causes the reduction in the grain size. Combined with transmission electron microscopy (TEM) observation and d electron theory analysis, it can be speculated that Sn addition can suppress the precipitation of ω phase. With increasing Sn content, fracture strength invariably decreases from 962 to 792 MPa, whereas the yield strength firstly decreases and then increases. The lowest yield stress for the stress-induced martensitic transformation of 220 MPa can be obtained in Ti-V-Al shape memory alloy by adding 3.0 at.% Sn. By optimizing 1.0 at.% Sn, the excellent ductility with a largest elongation of 42.1% can be gained in Ti-V-Al shape memory alloy, which is larger than that of the reported Ti-V-Al-based shape memory alloys. Besides, as a result of solution strengthening and grain refinement, Ti-V-Al-based shape memory alloy with 5.0 at.% Sn possesses the highest yield strength, further contributing to the excellent strain recovery characteristics with 4% fully recoverable strain.

关 键 词：Ti-V-Al alloy Lightweight shape memory alloy Microstructural features Mechanical properties strain recoverycharacteristics 

分 类 号：TG665[金属学及工艺—金属切削加工及机床] TG146.15[一般工业技术—材料科学与工程]