摘要
The design of alloys with simultaneous high strength and high ductility is still a difficult challenge.Here,we propose a new approach to designing multi-phase alloys with a synergistic combination of strength and ductility by engineering heterogeneous precipitate microstructures through the activation of different transformation mechanisms.Using a two-phase titanium alloy as an example,phase field simulations are carried out firstly to design heat treatment schedules that involve both conventional nucleation and growth and non-conventional pseudospinodal decomposition mechanisms,and the calculated microstructures have been evaluated by crystal plasticity finite element modeling.According to simulations,we then set a two-step heat treatment to produce bimodalα+βmicrostructure in Ti-10V-2Fe-3Al.Further mechanical testing shows that the ductility of the alloy is increased by~50%and the strength is increased by~10%as compared to its unimodal counterpart.Our work may provide a general way to improve the mechanical properties of alloys through multiscale microstructure design.
基金
the National Key Research and Development Program of China(No.2016YFB0701302)
the National Natural Science Foundation of China(Nos.52171012 and 51931004)
“H2”High-Performance Cluster,the internal City University of Hong Kong under the Programs 7004894 and 9380060。
