【摘要】 采用扫描电镜和透射电镜等分析手段研究新型Ti-22Al-25Nb-1Mo-1V-1Zr-0.2Si (摩尔分数,%)合金经不同时效热处理调控的显微组织演变与650°C、150 MPa下的蠕变变形行为。结果表明,合金的初始显微组织由α2、B2和O相构成。显微组织对热处理温度非常敏感,随着热处理温度的提高,合金的初始显微组织发生改变,其析出的板条O相的厚度增加,长度变短。而合金的抗蠕变性能与显微组织特征参数和板条O相的体积分数有关,板条O相的厚度增加是蠕变强度提高的主要原因。更多还原

【Abstract】 The microstructural evolution and creep deformation behavior which were adjusted and controlled by age treatment of a novel Ti-22Al-25Nb-1Mo-1V-1Zr-0.2Si(mole fraction, %) alloy, were investigated. The microstructures were obtained at different heat treatment temperatures and analyzed by SEM and TEM techniques. The creep behavior of the alloy was studied at 650 °C, 150 MPa for 100 h in air. The results showed that the initial microstructure mainly contained lath-like α2, B2, and O phases.The precipitated O phase was sensitive to aging temperature. With the aging temperature increasing, the thickness of the precipitated O phase was also increased, and the length was shortened. The creep resistance of this alloy was relevant to the morphology and volume faction of the lamellar O phase. The increase of lamellar O phase in thickness was the main reason for the improved creep properties.更多还原