CAJ | 학술논문

采用拉伸测试、维氏硬度测试、电阻率-温度曲线测试及扫描电镜和透射电镜观察显微组织的方法研究冷轧变形量为25%的Ti 50 Ni 47 Fe 3合金经450~750°C下1 h退火后的显微组织和性能。结果表明，冷轧变形增强了合金的抗拉强度和屈服强度，冷轧变形后形成的应力场有助于R相变的发生。随着退火温度的升高，合金的抗拉强度和屈服强度下降，伸长率增大；当退火温度高于650°C时，强度和伸长率趋于稳定。电阻-温度曲线表明，在升、降温过程中发生两阶段相变B2-R-B19′。随着退火温度的升高，合金的相变温度降低；当退火温度高于650°C时，相变温度趋于稳定。随着退火温度的升高，合金依次发生回复、再结晶和晶粒长大。
채용랍신측시、유씨경도측시、전조솔-온도곡선측시급소묘전경화투사전경관찰현미조직적방법연구랭알변형량위25%적Ti 50 Ni 47 Fe 3합금경450~750°C하1 h퇴화후적현미조직화성능。결과표명，랭알변형증강료합금적항랍강도화굴복강도，랭알변형후형성적응력장유조우R상변적발생。수착퇴화온도적승고，합금적항랍강도화굴복강도하강，신장솔증대；당퇴화온도고우650°C시，강도화신장솔추우은정。전조-온도곡선표명，재승、강온과정중발생량계단상변B2-R-B19′。수착퇴화온도적승고，합금적상변온도강저；당퇴화온도고우650°C시，상변온도추우은정。수착퇴화온도적승고，합금의차발생회복、재결정화정립장대。
Mechanical and shape memory properties of a Ti50Ni47Fe3 alloy annealed at 450-750 °C for 1 h after a cold-rolled reduction of 25%were investigated by phase transformation analysis and microstructure characterization using tensile tests, Vickers hardness tests, electrical resistivity-temperature tests, SEM and TEM. From the results of the tensile, it can be inferred that the fracture stress and yield stress decreased and the fracture elongation increased as the annealing temperature increased for the rolled Ti50Ni47Fe3 alloy. They reached stead values when the temperature was above 650 °C. The change in Vickers hardness corresponded to the change in the fracture stress and yield stress. The electrical resistivity-temperature curves suggest that a two-stage martensitic transformation (B2-R-B19′) occurred during cooling and heating. The transformation temperatures decreased to lower temperatures when the annealing temperature was increased and maintained the same after the annealing temperature reached 650 °C. TEM revealed the distinct processes occurring at elevated temperatures:recovery, polygonization, and recrystallization.