Microstructure instabilities of the fully lamellar Ti-45Al-8.5Nb-（W,B,Y） alloy were investigated by SEM and TEM after long-term thermal cycling（500 and 1000 thermal cycles） at 900 °C. Two major categories of ...Microstructure instabilities of the fully lamellar Ti-45Al-8.5Nb-（W,B,Y） alloy were investigated by SEM and TEM after long-term thermal cycling（500 and 1000 thermal cycles） at 900 °C. Two major categories of microstructure instability were produced in the alloy after the thermal cycling： 1） The discontinuous coarsening implies that grain boundary migrations are inclined to occur in the Al-segregation region after the long-term thermal cycling, especially after 1000 thermal cycles. Al-segregation can be reduced during the process of long-term thermal cycling as a result of element diffusion; 2） The α2 lamellae become thinner and are broken after 1000 thermal cycles caused by the dissolution of α2 lamellae through phase transformation of α2→γ. The γ grains nucleate within the α2 lamellae or（α2＋γ） lamellae in a random direction.展开更多
针对 TiAl 基合金的显微组织控制,综述了 TiAl 基合金中几种常见的组织演变,着重论述了变形 TiAl基合金在热处理过程中的晶拉长大及动力学分析,TiAl 基合盒在冷却时层状组织的形成和全层状 TiAl 基合盒在高温时的非连续粗化这3种组织演...针对 TiAl 基合金的显微组织控制,综述了 TiAl 基合金中几种常见的组织演变,着重论述了变形 TiAl基合金在热处理过程中的晶拉长大及动力学分析,TiAl 基合盒在冷却时层状组织的形成和全层状 TiAl 基合盒在高温时的非连续粗化这3种组织演变的研究现状和面临的问题。展开更多
基金Project(2011CB605500)supported by National Basic Research Program of ChinaProject(51171015)supported by National Natural Science Foundation of China+2 种基金Project(2012M520166)supported by China Postdoctoral Science FoundationProject(2012Z-06)supported by State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,ChinaProject(FRF-TP-12-164A)supported by Fundamental Research Funds for the Central Universities of China
文摘Microstructure instabilities of the fully lamellar Ti-45Al-8.5Nb-（W,B,Y） alloy were investigated by SEM and TEM after long-term thermal cycling（500 and 1000 thermal cycles） at 900 °C. Two major categories of microstructure instability were produced in the alloy after the thermal cycling： 1） The discontinuous coarsening implies that grain boundary migrations are inclined to occur in the Al-segregation region after the long-term thermal cycling, especially after 1000 thermal cycles. Al-segregation can be reduced during the process of long-term thermal cycling as a result of element diffusion; 2） The α2 lamellae become thinner and are broken after 1000 thermal cycles caused by the dissolution of α2 lamellae through phase transformation of α2→γ. The γ grains nucleate within the α2 lamellae or（α2＋γ） lamellae in a random direction.
