니켈-티타늄 와이어의 열처리에 따른 부하-변위 특성 변화

Abstract

Nickel-titanium alloy wire possesses excellent spring-back properties, shape memory and super-elasticity. In order to adapt this wire to clinical use, it is necessary to bend as well as to control its super-elastic force. The purpose of this study is to evaluate the effects of heat treatment on the load-deflection properties and transitional temperature range(TTR) of nickel-titanium wires. The nickel-titanium wires with different diameter(.016" × .022", .018" × .025" and .0215" × .028") were used. The samples were divided into 4 groups as follow: group 1 , post segment of wire( 25 mm ) without heat treatment; group 2, post segment of wire( 25 mm ) with heat treatment only; group 3, ant segment with bending and heat treatment; group 4, ant segment with bending and 1 sec over heat treatment. We used three point bending test to evaluate the change of the load-deflection curve and took DSC (different scanning calorimetry) to check the change of Af temperature. The results show that 1. In three point bending test, nickel-titanium wires with heat treatment only had higher load-deflection curve and loading and unloading plateau than nickel-titanium wires without heat treatment. 2. Nickel-titanium wires with heat treatment had lower Af temperature than nickel-titanium wires without heat treatment. 3. Nickel-titanium wires with heat treatment and bending had higher load-deflection curve than nickel-titanium wires with heat treatment and nickel-titanium wires without heat treatment. Nickel-titanium with heat treatment of over 1 sec and bending had the highest load-deflection curve. 4. Nickel-titanium wires with heat treatment and bending had lower Af temperature, Nickel-titanium wires with heat treatment of over 1 sec and bending had the lowest Af temperature.