Ti5Mo5V2Cr3Al合金中绝热剪切带的微观结构演化

Microstructure Evolution in Adiabatic Shear Band in Ti-5Mo-5V-2Cr-3Al Alloy

摘要:

利用分离式Hopkinson压杆，对Ti5Mo5V2Cr3Al (TB10)合金帽形试样进行强迫剪切试验，通过光学显微镜和透射电镜技术观测其绝热剪切带(ASB)内的微观结构。结果表明，ASB的过渡区由具有高位错密度的沿着剪切方向的宽度为20~50 nm的拉长组织构成；剪切带中心由大量低位错密度(相对ASB的过渡区)的直径为50~100 nm的晶粒组成，具有典型的再结晶组织特征。在绝热剪切变形过程中ASB内的平均绝热温升约为784 ℃。ASB内发生了动态再结晶，晶粒尺寸为50~100 nm

Abstract:

Dynamic testing of Ti-5Mo-5V-2Cr-3Al (TB10) alloy was carried out in hat-shaped specimens by a split Hopkinson pressure bar (SHPB) technique. The microstructure of adiabatic shear band (ASB) in TB10 alloy was investigated by means of OM and TEM. The results show that the transition zone between the shear band and the matrix is composed of grains of 20-50 nm in width with high dislocation density, and the grains are elongated along the shear direction. The center of the shear band consists of a number of recrystallized grains with diameters of 50-100 nm and low dislocation density, exhibiting typical recrystallization characteristics. The average value of temperature rising in the ASB during the adiabatic shearing deformation is about 784 oC. Dynamic recrystallization occurs in ASB and the grain sizes are about 50-100 nm