摘要
利用相场法显微组织模拟研究了外加应力对Ti-25Al-10Nb(摩尔分数/%)合金中α2→O相相变所产生显微组织几何特征的作用.结果表明,当外加应力达到390MPa时,就开始对O相析出形貌具有显著作用.外加应力改变O相析出形貌是因为:(1)外加应力使O相析出的总量增加,(2)外加应力诱发取向有利的O相变体析出并抑制其它O相变体的析出.外加应力大小对O相析出平均尺寸的影响可达106%,并且O相析出的尺寸标准差随外加应力增加而显著增大.
The applied stress effect on topological character of α2→O microstructure in Ti - 25Al - 10Nb （ mole fraction / % ） alloy is studied by phase field approach. Results show that applied stress affects the morphology significantly when its magnitude is over 390 MPa. There are two reasons why the morphology is influenced by applied stress. The one is that applied stress increases the volume fraction of the O phase. The other is that applied stress promotes the precipitation of the favored variants of the O phase and retards the precipitation of other variants. The effect of the applied stress magnitude on the average size of O phase is up to 106% and the size standard deviation of O phase increases considerably with applied stress increasing.
出处
《材料与冶金学报》
CAS
2007年第1期39-44,49,共7页
Journal of Materials and Metallurgy
基金
国家自然科学基金资助项目(No.50471024和50171018)
