CAJ | 학술논문

通过 X 射线衍射分析(XRD)、透射电子显微观察(TEM)、差式扫描量热分析(DSC)与拉伸实验研究时效处理对Ti48.4Ni51.1Cr0.5合金显微组织、马氏体相变与超弹性的影响规律与机制。经400°C 时效处理30 min后，合金中形成Ti3Ni4析出相。当时效温度介于400°C和500°C之间时，合金表现出两步马氏体相变。经时效处理的Ti48.4Ni51.1Cr0.5合金在室温下表现出优异的超弹性。随时效温度自300°C升高到450°C，超弹性恢复率增加。继续升高时效温度，恢复率下降。超弹性应力滞后表现出相反的变化趋势。通过分析Ti3Ni4析出相随时效处理的演化规律解释了时效处理与马氏体相变和超弹性之间的关系。
통과 X 사선연사분석(XRD)、투사전자현미관찰(TEM)、차식소묘량열분석(DSC)여랍신실험연구시효처리대Ti48.4Ni51.1Cr0.5합금현미조직、마씨체상변여초탄성적영향규률여궤제。경400°C 시효처리30 min후，합금중형성Ti3Ni4석출상。당시효온도개우400°C화500°C지간시，합금표현출량보마씨체상변。경시효처리적Ti48.4Ni51.1Cr0.5합금재실온하표현출우이적초탄성。수시효온도자300°C승고도450°C，초탄성회복솔증가。계속승고시효온도，회복솔하강。초탄성응력체후표현출상반적변화추세。통과분석Ti3Ni4석출상수시효처리적연화규률해석료시효처리여마씨체상변화초탄성지간적관계。
The effect of aging on microstructure, martensitic transformation and superelasticity of a Ti48.4Ni51.1Cr0.5 alloy was investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC) analysis and tensile tests. When the alloy was aged at 400 °C for 30 min, Ti3Ni4 precipitate appears. When aged at a temperature between 400 °C and 500 °C, the samples show a two-stage martensitic transformation. The aged Ti48.4Ni51.1Cr0.5 alloy exhibits a well-defined superelasticity at room temperature. The recovery ratio increases with increasing aging temperature from 300 to 450 °C. Further increase of aging temperature leads to the decrease of recovery ratio. The stress hysteresis shows the opposite dependence on aging temperature. The relationship between aging treatment and martensitic transformation and superelasticity can be rationalized by the evolution of Ti3Ni4 precipitate.