Effect of multiaxial deformation Max-strain on the structure and properties of Ti-Ni alloy

6th International Conference on Nanomaterials by Severe Plastic Deformation

材料科学;化学

Khmelevskaya, I. Yu^1 ; Kawalla, R.^1 ; Prokoshkin, S.D.^1 ; Komarov, V.S.^1

Freiberg University of Technology and Mining, NUST MISIS, Moscow, Russia^1

关键词: Axial deformations;    Constant temperature;    Functional properties;    Physical simulation;    Recoverable strain;    Severe plastic deformations;    Structure and properties;    Ultra-fine-grained;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/63/1/012108/pdf
DOI  :  10.1088/1757-899X/63/1/012108

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

The severe plastic deformation (SPD) forming ultrafine-grained (nanocrystalline or nanosubgrained) structure is one of the most effective ways to improve the functional properties of Ti-Ni-based shape memory alloys [1, 2]. In the present work, the SPD of near-equiatomic Ti-Ni alloy was carried out using the multi-axial deformation module Max-strain, which is a part of the physical simulation system "Gleeble 3500". The deformation was performed at a constant temperature of 400°C with speed of 0.5 mm/s in six passes without interpass pauses. The accumulated true strain was about 3. As a result, a mixed ultrafine-grained/subgrained structure with grain/subgrain sizes from 50 to 300 nm and a high density of free dislocations formed. The resulting structure is close to a nanoscale region and provides a significant advantage in the basic functional property-completely recoverable strain-as compared with a conventional recrystallized structure: 7% versus 2%.