脉冲强磁场拉伸时TC4钛合金的塑变能力和微观组织

Plasticity and Microstructure of TC4 Alloy Subjected to the High Magnetic Field Tensile Test

在磁感应强度(B)1、3和5 T条件下对TC4钛合金进行拉伸实验处理,研究了B值对合金延伸率、相特征、晶体结构和位错密度等的影响。结果表明:拉伸过程脉冲强磁场的施加提高了钛合金的延伸率,当B=3 T时,合金的延伸率达到最大值12.41%,较未施加磁场试样增长了23.98%,且B=3 T为延伸率从上升到下降的转折点。磁场处理促使了β相向α相的转变,并促进了晶面向着易滑移方向产生了择优取向。位错密度随B值变化呈现先增后减的趋势,在3 T时达到最大值。分析认为位错密度的变化首先是因为磁场下位错应变能增加,其次是磁场促进了自由基对从S态向T态的转变,并从量子尺度分析了最优B值为3 T的理论依据。

The tensile test of TC4 alloy was carried out in the presence of a high pulsed magnetic field. The effects of magnetic induction intensity（B=0, 1, 3, 5 T） on the elongation, phase characteristics, crystal structure and dislocation density were investigated. The results show that the imposed magnetic field enhances the elongation. At 3 T the elongation arrives at the maximum of 12.41%, which is enhanced by 23.98% compared to that of 0 T sample. The 3 T parameter is ascertained as a traverse point from an increase tendency to a decrease one. Furthermore, the magnetic field accelerates the phase transformation from β to α together with the orientation preference of crystal plane along the slipping direction. The dislocation density first increases and then falls. At 3 T it arrives at the utmost. The phenomenon is attributed to the enhancement of dislocation strain energy in the presence of magnetic field. Next, the magnetic field promotes the transition from singlet to triplet state. At last the inevitability of optimized 3 T parameter was further discussed in the quantum view.