Effect of heat treatment on microstructure and functional properties of additively manufactured NiTi shape memory alloys

Zhu，Jia Ning1; Zhu，Weijia1; Borisov，Evgenii2; Yao，Xiyu3; Riemslag，Ton1; Goulas，Constantinos4; Popovich，Anatoly2; Yan，Zhaorui1; Tichelaar，Frans D.5; Mainali，Durga P.1; Hermans，Marcel1; Popovich，Vera1

2023-12-10

10.1016/j.jallcom.2023.171740

Journal of Alloys and Compounds   Impact Factor & Quartile

0925-8388

1873-4669

Additive manufacturing of NiTi shape memory alloys has attracted attention in recent years, due to design flexibility and feasibility to achieve four-dimensional (4D) function response. To obtain customized 4D functional responses in NiTi structures, tailorable phase transformation temperatures and stress windows as well as one-way or two-way shape memory properties are required. To achieve this goal, various heat treatments, including direct aging, annealing and annealing followed by aging, were optimized for the Ti-rich NiTi (Ni49.6Ti (at. %)) fabricated by laser powder bed fusion (L-PBF). Microstructural evolution, phase transformation, precipitation and shape memory behaviour were systematically investigated by multiscale correlative microstructural, differential scanning calorimetry analysis and thermomechanical analysis. Based on optimized heat treatments, ∼25 K phase transformation temperature windows and ∼90 MPa stress windows were achieved for the one-way shape memory effect. Solutionized annealing was found to be the most effective way to improve one-way shape memory degradation resistance, due to the reduction of defects and solid solution strengthening. One of the main findings of this study is that the heterogonous microstructures between hard intergranular TiNiO and soft NiTi matrix, induced by solutionized annealing with subsequent aging, result in strain partitioning and enclosing the internal stress state, which was found to promote a pronounced two-way shape memory effect response. The results of this work provide in-depth knowledge on tailoring and designing functional shape memory characteristics via heat treatments, which contributes to expanding L-PBF NiTi application fields, such as biomedical implants, aerospace components, and other advanced engineering applications.

Heat treatment Laser powder bed fusion Microstructure NiTi alloys Shape memory effect

SCI

English

Others

Russian Science Foundation[19-79-30002];

Chemistry ; Materials Science ; Metallurgy & Metallurgical Engineering

Chemistry, Physical ; Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering

WOS:001062146400001

ELSEVIER SCIENCE SA

MATERIALS SCIENCE

2-s2.0-85167968305

Scopus

1.Department of materials science and engineering,Delft University of Technology,Netherlands
2.Peter the Great Saint-Petersburg Polytechnic University,Saint Petersburg,Russian Federation
3.Department of Materials Science and Engineering,Southern University of Science and Technology,Shenzhen,China
4.Department of Design Production & Management,University of Twente,Enschede,Netherlands
5.Kavli Institute of Technology,Quantum Nanoscience,Delft University of Technology,Delft,Netherlands

Zhu，Jia Ning,Zhu，Weijia,Borisov，Evgenii,et al. Effect of heat treatment on microstructure and functional properties of additively manufactured NiTi shape memory alloys[J]. Journal of Alloys and Compounds,2023,967.

Zhu，Jia Ning.,Zhu，Weijia.,Borisov，Evgenii.,Yao，Xiyu.,Riemslag，Ton.,...&Popovich，Vera.(2023).Effect of heat treatment on microstructure and functional properties of additively manufactured NiTi shape memory alloys.Journal of Alloys and Compounds,967.

Zhu，Jia Ning,et al."Effect of heat treatment on microstructure and functional properties of additively manufactured NiTi shape memory alloys".Journal of Alloys and Compounds 967(2023).