运用电子背散射衍射(EBSD)和取向成像显微技术(OIM)研究了退火时间和冷轧变形量对Incoloy 800合金晶界特征分布的影响。结果显示,随着退火时间的延长,总的低ΣCSL(coincidence site lattice,Σ≤29)晶界比例在60%～70%范围内缓慢增长,Σ...运用电子背散射衍射(EBSD)和取向成像显微技术(OIM)研究了退火时间和冷轧变形量对Incoloy 800合金晶界特征分布的影响。结果显示,随着退火时间的延长,总的低ΣCSL(coincidence site lattice,Σ≤29)晶界比例在60%～70%范围内缓慢增长,Σ1晶界比例随Σ3晶界比例上升而下降。随着变形量的增加,总的低ΣCSL晶界、Σ3晶界、Σ9晶界和Σ27晶界比例均呈现先增加后降低的趋势,而Σ1晶界相反,出现先降低后增加的趋势。优化的Incoloy 800合金晶界工程工艺为:在980℃固溶处理15 min,冷轧5%后在980℃退火15 min。展开更多
We link different microstructures to tribological behaviors of Ti-50.8 Ni(mole fraction, %) in reciprocating mode at room temperature(20 ℃). Hot-rolled alloys with B2 phase exhibit lower coefficient of friction and w...We link different microstructures to tribological behaviors of Ti-50.8 Ni(mole fraction, %) in reciprocating mode at room temperature(20 ℃). Hot-rolled alloys with B2 phase exhibit lower coefficient of friction and wear rate compared to the ones with B19?. Stress-induced martensitic transformation occurs during sliding. However, multi-pass hot rolling weakens the wear resistance. In this study, microstructures were characterized through electron backscatter diffraction and transmission electron microscopy(EBSD/TEM). From the concept of energy conservation, the effects of weak intensity of hot-rolled textures on the wear resistance are minimal. Based on the result that the alloy with a higher portion of coincidence site lattice boundaries shows lower martensitic start transformation temperature in the DSC curves than that with higher KAM values, the delay on B2-B19? transformation from {112}B2 twins outweighs dislocations. Moreover, widely distributed small-angle grain boundaries owing to dynamic recovery improve the wear resistance effectively compared to those that are well-recrystallized.展开更多
采用工厂生产线上的冷拔机对镍基825合金管材进行冷拔加工后再退火，进行晶界工程（GBE）处理．利用EBSD和取向成像显微技术（OIM）研究了不同冷拔变形量和不同退火温度对825合金晶界特征分布（GBCD）的影响．结果表明。合金在冷拔变形...采用工厂生产线上的冷拔机对镍基825合金管材进行冷拔加工后再退火，进行晶界工程（GBE）处理．利用EBSD和取向成像显微技术（OIM）研究了不同冷拔变形量和不同退火温度对825合金晶界特征分布（GBCD）的影响．结果表明。合金在冷拔变形5％，1050℃退火10min时，低刮直重合位置点阵（2CSL，coincidence site lattice，∑≤29）晶界的比例可提高到75％以上（Palumbo—Aust标准），同时形成大尺寸的“互有弱“取向关系晶粒的团簇”显微组织（n=1，2，3，…）．随着再结晶退火前冷拔变形量的增加，晶粒团簇的尺寸减小，同时低∑CSL晶界的比例也下降，并且低∑CSL晶界的比例随晶粒尺寸的增加而下降．当合金经过5％的冷拔变形后，在1050～1125℃退火处理10min时的晶界特征分布无明显变化，退火温度对合金的低∑CSL晶界比例影响较小；当经过3％，7％和10％的冷拔变形后，合金的低∑CSL晶界比例随着退火温度的升高不断下降．展开更多
基金financially supported by the National Natural Science Foundation of China-Aerospace Science and Technology Corporation of China Aerospace Advanced Manufacturing Technology Research Joint Fund (U1737204)the National Natural Science Foundation of China (51673205)the Key Research Program of Frontier Science,Chinese Academy of Sciences (QYZDJ-SSW-SLH056)。
文摘We link different microstructures to tribological behaviors of Ti-50.8 Ni(mole fraction, %) in reciprocating mode at room temperature(20 ℃). Hot-rolled alloys with B2 phase exhibit lower coefficient of friction and wear rate compared to the ones with B19?. Stress-induced martensitic transformation occurs during sliding. However, multi-pass hot rolling weakens the wear resistance. In this study, microstructures were characterized through electron backscatter diffraction and transmission electron microscopy(EBSD/TEM). From the concept of energy conservation, the effects of weak intensity of hot-rolled textures on the wear resistance are minimal. Based on the result that the alloy with a higher portion of coincidence site lattice boundaries shows lower martensitic start transformation temperature in the DSC curves than that with higher KAM values, the delay on B2-B19? transformation from {112}B2 twins outweighs dislocations. Moreover, widely distributed small-angle grain boundaries owing to dynamic recovery improve the wear resistance effectively compared to those that are well-recrystallized.
文摘采用工厂生产线上的冷拔机对镍基825合金管材进行冷拔加工后再退火，进行晶界工程（GBE）处理．利用EBSD和取向成像显微技术（OIM）研究了不同冷拔变形量和不同退火温度对825合金晶界特征分布（GBCD）的影响．结果表明。合金在冷拔变形5％，1050℃退火10min时，低刮直重合位置点阵（2CSL，coincidence site lattice，∑≤29）晶界的比例可提高到75％以上（Palumbo—Aust标准），同时形成大尺寸的“互有弱“取向关系晶粒的团簇”显微组织（n=1，2，3，…）．随着再结晶退火前冷拔变形量的增加，晶粒团簇的尺寸减小，同时低∑CSL晶界的比例也下降，并且低∑CSL晶界的比例随晶粒尺寸的增加而下降．当合金经过5％的冷拔变形后，在1050～1125℃退火处理10min时的晶界特征分布无明显变化，退火温度对合金的低∑CSL晶界比例影响较小；当经过3％，7％和10％的冷拔变形后，合金的低∑CSL晶界比例随着退火温度的升高不断下降．
