片层宽度对TC21钛合金动态压缩性能及其绝热剪切敏感性的影响规律

Effects of Lamellar α Thickness on Dynamic Mechanical Properties and Sensitivity to Adiabatic Shear Banding of TC21 Alloy

研究了冷却速率对TC21钛合金片层宽度的影响,并通过分离式霍普金森压杆,进一步研究了片层宽度对动态压缩性能及其绝热剪切敏感性的影响。结果表明:随着冷却速率的降低,片层组织TC21钛合金的片层宽度由0.57μm增宽到6.49μm;在动态压缩试验条件下,片层组织随着片层宽度增加,动态强度降低,而塑性应变呈现出相反的规律;在强迫剪切试验条件下,片层组织随着片层宽度增加,其绝热剪切敏感性降低,而随着撞击杆初速的提高,每种片层组织的绝热剪切敏感性均提高。

The α lamellar microstructures with different thicknesses were obtained by proper heat treatments of TC21 alloy, and the dynamic mechanical properties and sensitivity to adiabatic shear banding were investigated by the Split Hopkinson Pressure Bar. The results show that the thickness of lamellar α increases from 0.57 to 6.49 μm with the decreasing of the cooling rate. Under the dynamic compression condition, the dynamic strength decreases as the thickness of lamellar α increases; while the dynamic strain exhibits an opposite trend. Under the dynamic shear condition, the sensitivity to adiabatic shear banding increases with the decreasing of the thickness of lamellar α at the same impact velocity, and the sensitivity to adiabatic shear banding increases for the same microstructure with the increasing of impact velocity.