工业纯钛在中低温下的Fields-Backofen和改进型Johnson-Cook方程（英文）  

Fields–Backofen and a Modified Johnson-Cook Model for CP-Ti at Ambient and Intermediate Temperature

作　　者：常乐[1] 周昌玉[1] 彭剑[1] 李建[1] 贺小华[1] 

机构地区：[1]南京工业大学,江苏南京211816

出　　处：《稀有金属材料与工程》2017年第7期1803-1809,共7页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China(51475223,51075199)

摘　　要：通过单轴拉伸试验研究工业纯钛在283~573 K下应变速率范围为0.000 05~0.005 s^(-1)的流动应力行为,确定工业纯钛应变速率敏感性及应变强化指数随温度的定量变化。结果表明:工业纯钛的应变速率敏感性在283~423 K不显著,应变强化指数在353~573 K随温度变化而增加。基于温度变化的修正型Fields-Backofen方程,建立了能够描述工业纯钛塑性流动应力行为的数学模型。同时,考虑应变、应变速率及温度之间的相互作用,对传统的Johnson-Cook方程进行改进。与传统的Johnson-Cook方程相比,改进型的Johnson-Cook方程与实验结果吻合更好,证明改进型Johnson-Cook方程预测工业纯钛塑性流动应力的精确性。The flow stress behavior of commercial pure titanium（CP-Ti） was studied by uniaxial tension tests at temperatures ranging from 283 to 573 K and strain rates from 0.000 05~0.005 s^（-1）. The tensile properties of CP-Ti was investigated to determine the quantitative variation of the strain rate sensitivity and the strain hardening with temperature. The results show that the strain rate sensitivity of CP-Ti at 283~423 K is not obvious and strain hardening index increases with temperature at 353~573 K. A mathematical model using an updated Fields-Backofen（FB） equation based on temperature changing was established to describe the plastic flow stress behavior of CP-Ti. Meanwhile by considering the coupled effects of strain, strain rate and temperature, a modified Johnson-Cook（JC） model were proposed to predict the flow behavior. Compared with the original JC model, the modified JC model shows better agreement with the experimental stress, which validates the accuracy of the modified model describing the plastic flow stress of CP-Ti.

关 键 词：工业纯钛 拉伸变形 Fields-Backofen方程 Johnson-Cook方程 

分 类 号：TG146.23[一般工业技术—材料科学与工程]