摘要
基于XRD、OM、SEM和TEM分析,研究超高强Ti-15Mo-2.7Nb-3Al-0.2Si钛合金的组织演变及强化行为。结果表明,位错强化和析出强化效应对该合金的屈服强度影响较大。冷轧+再结晶+冷轧+双时效组合工艺可获得1518 MPa的最高屈服强度,这主要归因于显微组织中的高密度残存位错及密集而细小的次生α相。建立复合强化模型,其预测误差在16.6%以内。此外,研究发现次生α相体积分数的增加可以不断强化晶内区域,这使得沿晶断裂开始出现并逐渐占据整个断裂面。
The microstructure evolution and strengthening behavior of the ultra-high strength Ti−15Mo−2.7Nb−3Al−0.2Si titanium alloy were studied utilizing XRD,OM,SEM,and TEM analyses.The results show that the dislocation-strengthening and precipitation-strengthening effects could mostly affect the yield strength of this alloy.The highest yield strength of 1518 MPa was obtained under a combined process of cold rolling+recrystallization+cold rolling+duplex aging.This trend is mainly due to the high density of remaining dislocations,as well as dense and thin secondary α phases in microstructures.A theoretical composite-strengthening model was built,and the prediction error is within 16.6%.Furthermore,it is found that increasing the content of the secondaryαphase can continuously strengthen the intragrain zone.This feature causes the intergranular fracture to appear and gradually dominate the fracture surface.
作者
石晓辉
张琪
荆镇
范智渊
刘江林
乔珺威
Xiao-hui SHI;Qi ZHANG;Zhen JING;Zhi-yuan FAN;Jiang-lin LIU;Jun-wei QIAO(College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China;College of Mechanical and Vehicle Engineering,Taiyuan University of Technology,Taiyuan 030024,China)
基金
the financial support from the Fundamental Research Program of Shanxi Province,China(No.202203021211130)
the National Natural Science Foundation of China(Nos.51801132,52075359)。
