构建了基于火焰枪的局部热处理系统,对消除超弹性镍钛形状记忆合金(SMA)弹簧端部目标部位的超弹性开展了初步实验研究,并结合温度与硬度测试,探讨了热处理温度、保温时间、加热方式对超弹性消除效果、处理部位颜色的影响。结果表明,该系统可在770℃以上、极短的保温时间内有效消除镍钛SMA弹簧目标部位的超弹性而主体几乎不受影响。热处理温度是目标部位超弹性能否消除的决定性因素,而保温时间的影响不大。灼烧方式比热传导方式更易引起目标部位的颜色变化。
A local heat treatment system was constructed based on a flame gun and the preliminary experimental study on the elimination of superelasticity of the target site at one end of the nickel-titanium shape memory alloy (SMA) springs was carried out. The temperature and hardness of the samples were detected and correlated to explore the influence of heat treatment temperature, holding time and heating method on eliminating the superelasticity and the color change of the samples. The results show that the developed system can effectively eliminate the superelasticity of the target site and meanwhile keep the main body of the samples unaffected, on condition that the heat treatment temperature reaches above 770 ℃, whereas the holding time can be very short. The heat treatment temperature is the decisive factor in eliminating the superelasticity of the target site, while the holding time has little effect. Burning heating is more likely to cause a color change at the target site of the samples than the thermal conductive heating.