脉冲电流处理对钛板位错可动性的影响

摘要

To investigate the effect of the electropulsing on dislocation mobility,specimens cut from the cold-rolled titaniun sheet were treated by high density electropulsing with the maximum current density of 7.22,7.64,7.96 kA/mm2,pulse period 110 μs.The intemal friction and elastic modulus were measured by a dynamic mechanical analyzer (DMA).When strain amplitude lowers a certain critical one,the damping of the electropulsed titanium sheet is lower than that of the cold-rolled one.When the strain amplitude exceeds the critical one,the damping of the electropulsed titanium sheet is extraordinarily higher than that of the cold-rolled or conventional annealed one.Furthermore,it is found that the damping peak of the electropulsed titanium sheet shifts to lower temperature compared with the conventional annealed one.It is demonstrated that the electropulsing treatment can decrease dislocation tangles and enhance dislocation mobility.%为了研究外场对钛板位错运动的影响,对冷轧纯态板试样进行高密度脉冲电流处理(最大电流密度7.22、7.64、7.96 kA/mm2,周期110 μs).应用动态机械分析仪(DMA)测量不同试样的内耗和弹性模量.结果表明:在变形的最初阶段,脉冲电流处理试样的内耗值低于冷轧试样的；但当应变幅值超过一定值后,脉冲电流处理试样的内耗值高于普通退火试样和冷轧试样的；并且在整个变形阶段,普通退火试样的内耗值总是低于冷轧试样和脉冲电流处理试样的.阻尼温度谱的研究结果表明:与普通退火试样相比,脉冲电流处理试样的阻尼峰值移向了低温区.试验结果证明了脉冲电流处理能够降低位错的缠结,提高位错的可动性.