TA2丝材循环拉伸力学性能研究

Study on Mechanical Properties of TA2 Wire in Cyclic Tensile

摘要:

为了研究循环载荷频次与力学行为之间的关系，通过试验对比了单轴拉伸与不同循环载荷次数下退火态TA2的力学性能。结果表明：在循环载荷20次范围内，TA2/M断后伸长率会随循环载荷次数的增多而增大；随着载荷的不断循环，材料晶粒位错密度逐渐增加、几何必要位错得到不断积累，使得TA2/M塑性变形阶段的拉伸应力出现缓慢上升；同时，由于塑性变形阶段加工硬化率的急剧下降，在颈缩阶段背应力和有效应力均呈现下降趋势。

Abstract:

In order to study the relationship between cyclic loading frequency and mechanical behavior, the mechanical properties of annealed TA2/M under uniaxial tension and cyclic tensile with different frequencies were compared by experiments. Within the range of 20 cycles loads， the elongation after fracture of TA2/M increased with the increase of cyclic loading times. With the continuous cycle of load， the dislocation density of the material grains increased gradually， and the necessary geometric dislocations accumulated， making the tensile stress in the plastic deformation stage of TA2/M increase slowly. At the same time， due to the sharp decrease of the work hardening rate in the plastic deformation stage， both the back stress and effective stress presented a downward trend in the necking stage.