A. B. Bondarev, V. N. Belyakov, Industrial center “MATEKS”, Moscow, Russia; M. A. Khusainov, Yaroslav the Wise Novgorod State University, Velikiy Novgorod, Russia; V. A. Andreev, Industrial center "MATEKS", Moscow, Russia
The goal of this paper is to present the results of the systematic research of the properties of the alloys Ti-50at.%-Ni and Ti-50,3at.%-Ni at the reduction ratio up to 90% after rolling and intermediate annealing at 600oC, 5 min. This type of annealing helped release the work hardening without changing the structure. Significant increase in the temperatures of martensitic transformations, magnitude of the memory effect, hardness and other mechanical properties before reduction ratio 30÷40% is shown. Further increase in the reduction ratio (ε) causes significant decrease in the mechanical properties and the temperature of reverse martensitic transformations along with the enhancement of the shape memory effect. The changes correspond well to the change in the phase composition of the alloy. Analysis of diffraction patterns shows that at the reduction ratio up to ~ 40% the phase composition is nonhomogeneous. A whole set of lines B2 ↔ B19′ of the phases of different intensity are singled out. With the increase in the reduction ratio a share of the martensitic phase grows up. The material becomes more plastic. This can be caused by accommodative twins contained in deformation martensite.
Summary: The paper presents the results of the systematic research of the properties of the alloys Ti-50at.%-Ni and Ti-50,3at.%-Ni at the reduction ratio up to 90% after rolling and intermediate annealing
