Reactive Ti/Ni multilayer composites produced via accumulative roll-bonding (ARB): post-annealing treatment

ABSTRACT

Ti/Ni multilayers, produced through the accumulative-roll bonding (ARB) process, serve as reactive multilayer, capturing energy to optimize manufacturing processes and contribute to TiNi (shape memory alloy) production. This research specifically examines the impact of the number of layers on microstructural and thermal properties after activation through heating. Energy-dispersive spectroscopy (EDS), field emission scanning electronmicroscopy (FESEM), and differential scanning calorimeter (DSC) were employed to analyse samples subjected to various ARB cycles. The findings indicate that in low-cycle ARB processing, the interdiffusion of Ni and Ti under normal conditions initiates the production of a very thin layer of TiNi at 800 °C, requiring extended holding times for increased thickness. Conversely, the formation of intermetallic compounds, particularly TiNi, and diffusion in high-cycle ARB-processed composites are accelerated. According to the DSC results, complete activation and phase transformation, accompanied by the release of energy (43–50 kJ/mol), occur at approximately 500–525°C without the need for any holding time. Consequently, for achieving a uniform TiNi phase, heat treatment of high-cycle ARB-processed composites up to 800°C – a temperature surpassing the activation temperature – without any holding time can be effectively employed.

KEYWORDS:

• Reactive Ti/Ni multilayer composites
• accumulative roll-bonding
• reactive layers

Acknowledgements

This work was supported by Shiraz University [grant number 95INT4M1974].

The authors of this article affirm that there is no conflict of interest concerning with the research, authorship, and/or publication.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work was supported by the Shiraz University [95INT4M1974].