Bending properties of Co-Ni-Cr-Mo alloy wire for orthodontic application

Abstract

In order to evaluate the clinical performance of the Co-Ni-Cr-Mo alloy wire in orthodontic application, bending properties of Co-Ni-Cr-Mo alloy wire was investigated in comparison with the conventional stainless steel wire and Co-Cr alloy wire. Three-point bending test was carried out for the wires with varied drawing rate up to 3.0 mm in deflection and then unloaded with 0.2 mm/s of loading/unloading speed. Bending yield load of the Co-Ni-Cr-Mo alloy wire increased and the residual deflection decreased with increasing wiredrawing rate. The best processing condition was decided as the wiredrawing rate of 78% with the age-hardening treatment. The bending elastic modulus of the Co-Ni-Cr-Mo alloy wire was higher than those of stainless steel wire and Co-Cr alloy wire. The bending strength of the Co-Ni-Cr-Mo alloy wire was lower than that of stainless steel wire and was comparable to that of Co-Cr alloy wire. © 2005 The Japan Institute of Metals.