Yoneyama T, Doi H, Hamanaka H, Yamamoto M, Kuroda T
Division of Metallurgy, Tokyo Medical and Dental University, Japan.
J Biomed Mater Res. 1993 Mar;27(3):399-402. doi: 10.1002/jbm.820270313.
The effect of heat treatment temperature on bending properties and transformation temperatures of a Ni-Ti alloy wire, 1.0 mm in diameter, was investigated so that superelasticity could be used in orthodontic appliances needing shape memory processes. The heat treatment process was at 713 K for 1.8 ks and between 673 K and 813 K for 1.8 ks. A three-point bending test and differential scanning calorimetry were performed. The transformation temperatures of the wires were lowered with increasing heat treatment temperature. The reverse transformation finishing temperature was below the body temperature with the treatment above 753 K. Residual deflection of the Ni-Ti wire after bending was small with the secondary heat treatment above 733 K. The load in the unloading process was less changeable and increased with the treatment temperature between 733-813 K. Secondary heat treatment in this range was suitable for using superelasticity in expansion arch appliances.
研究了热处理温度对直径为1.0毫米的镍钛合金丝弯曲性能和转变温度的影响，以便在需要形状记忆过程的正畸矫治器中使用超弹性。热处理过程为在713K下处理1.8千秒，以及在673K至813K之间处理1.8千秒。进行了三点弯曲试验和差示扫描量热法。随着热处理温度的升高，丝材的转变温度降低。在753K以上进行处理时，逆转变终了温度低于体温。在733K以上进行二次热处理后，镍钛丝弯曲后的残余挠度较小。在卸载过程中，载荷变化较小，且在733 - 813K之间随处理温度升高而增加。在此范围内的二次热处理适用于在扩弓矫治器中使用超弹性。
