片层组织TA15合金电致动态球化行为及动力学模型

Electrically-induced dynamic globularization behavior and related kinetics model of TA15 alloy with initial lamellar structure

摘要:

开展了脉冲电流辅助压缩试验，结合金相组织定量分析，对TA15钛合金片层组织的动态球化规律、机制以及球化动力学模型进行了深入研究。结果表明，电流密度的增大将进一步加剧流动软化现象，球化率随着电流密度的增大和变形量的增大而升。基于Avrami方程建立了TA15合金电致动态球化动力学模型，模型预测动态球化临界应变εc和完成动态球化应变εf的范围在0.090 ~ 0.187和5.02 ~ 6.31之间，且都随电流密度的增大而减小。球化动力学速率随着应变和电流密度的增大先增大后减小。此外，电流密度越大，球化动力学速率峰值越大，峰值对应的应变越小。

Abstract:

The dynamic globularization rules, underlying mechanisms and globularization kinetics model of TA15 alloy with initial lamellar structure were studied by pulsed electric current assisted compression tests and quantitative analysis of metallographic structure. The results indicate that the increased current density further promotes the flow softening phenomenon. The globularization rate increases with the increase of current density and pre-deformation. Based on the Avrami equation, a kinetics model of electrically-induced dynamic globularization for TA15 alloy is established. The model predicts that the ranges of the critical strain εc for dynamic globularization and the strain εf for completing dynamic globularization are between 0.090 - 0.187 and 5.02 - 6.31, respectively. And these two critical strains both decrease with the increase of current density. The globularization kinetics rate first increases and then decreases with the increase of pre-strain and current density. In addition, the higher the current density, the greater the peak globularization kinetics rate and the smaller the critical strain for this peak value.