摘要
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 macro- and micro-scopic investigation of high velocity deformation and adiabatic shearing for a β-titanium alloy TB-2 at low temperature and high strain rates by using a Split Hopkinson Pressure Bar. shows that (1) the dynamic mechanical behavior of TB-2 is highly susceptible to strain rate and temperature. and can be described by a thermal visco-plastic constitutive equation with the form(2) the naterial is more sensitive to adiabatic shearing at low environmental temperature than at room temperature, us well as the type and structure of adiabatic shear band at low temperature are different from that at room temperature. Moreover. by taking the environmental temperature. as a control-veriable into consideration. the two control-variables ther-mal-viscoplastic instability criterion of adiabatic shearing suggested by Wang can be generalized to a tri-control variables criterion. The theoretical prediction is in agreement with the experimental data.
出处
《爆炸与冲击》
EI
CAS
CSCD
北大核心
1989年第2期109-119,共11页
Explosion and Shock Waves
关键词
钛合金
变形
绝热剪切
低温
adiaharic shearing, thermal-viseoplastic instability,high velocity deformation,low temperature, titanium alloy
