Effect of Changing Temperature and Wire Cross Section on the Tribological Behavior of the NiTi Alloy

摘要

Orthodontic therapy generally begins with aligning and leveling phase, wherein a NiTi, superelastic wire is habitually attached, tied and activated to supply the required forces for teeth correction. Deactivation of the archwire following teeth movement will commonly lead to the sliding of wire through the adjoining bracket slots. This study aims to investigate the friction and wear behavior of a deflected NiTi wire sliding against a 316 stainless steel sample with the effect of changing the temperature and the shape of the wire. Superelastic NiTi wires with circular and rectangular cross-section were tested, in Fuzayama artificial saliva and at the temperatures met in the oral cavity, using a modified rotative tribometer. It was found that the tested parameters had a great effect on the tribological behavior of the studied tribo-couple. Indeed, the results showed an increase in the wear rate as the temperature increase because of the rise of the thermal stress within the tested NiTi alloy. It was also found that the wear of the rectangular archwires is more significant than the circular ones, this could be due to the nature of the initial tribo-contact condition.