论文部分内容阅读
采用SHPB技术在室温和低温下,对β相钛合金TB-2的高速变形特性和绝热剪切进行了宏观和微观研究。结果表明,TB-2是一个对应变率和温度敏感的材料,其热粘塑性本构特性可表为 α=(σ_0+E_(1ε)(1+glnε/ε_0)(1-α(T-T_n) /T_n)显微观察表明,TB—2在低温下比在常温下对绝热剪切更敏感。低温下绝热剪切带的形态和结构也和常温下有所不同。把文献[9]所建议的绝热剪切的热粘塑性失稳准则,应用到不同的环境温度下,本文建议了一个既依赖于应变和应变率,又依赖于环境温度的三变量准则。理论预示和试验结果符合较好。
The SHPB technique was used to investigate the high-speed deformation and adiabatic shear of β-phase titanium alloy TB-2 at room temperature and low temperature. The results show that TB-2 is a material that is sensitive to strain rate and temperature. The thermovisco-plastic constitutive properties of TB-2 can be expressed as follows: α = (σ 0 + E 1 (1 + glnε / ε 0) T_n) / T_n) shows that TB-2 is more sensitive to adiabatic shear at lower temperature than at room temperature, and the morphology and structure of adiabatic shear band at low temperature are also different from those at room temperature. The suggested thermal viscoplastic instability criterion for adiabatic shear applied to different ambient temperatures suggests a three-variable criterion that depends both on strain and strain rate and on ambient temperature. The theoretical predictions and test results are in agreement better.