超高强Ti-15Mo-2.7Nb-3Al-0.2Si钛合金的强化行为及模型  

Strengthening behavior and model of ultra-high strength Ti-15Mo-2.7Nb-3Al-0.2Si titanium alloy

作　　者：石晓辉[1] 张琪 荆镇 范智渊 刘江林 乔珺威[1] 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)

机构地区：[1]太原理工大学材料科学与工程学院,太原030024 [2]太原理工大学机械与运载工程学院,太原030024

出　　处：《Transactions of Nonferrous Metals Society of China》2024年第4期1136-1149,共14页中国有色金属学报（英文版）

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)。

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.

关 键 词：强化模型 超高强 强化行为 钛合金 Ti-15Mo-2.7Nb-3Al-0.2Si 

分 类 号：TG146.23[一般工业技术—材料科学与工程]