摘要
在应变速率为0．01～10．00s^-1、变形温度为700—850℃的条件下，通过热压缩实验研究Cu-Ag合金的高温流变行为，发现该合金高温流变应力对温度和应变速率比较敏感，且在不同条件下呈现的软化特征也有区别。通过双曲正弦本构方程和线性回归分析，得到了不同变形条件下，关于结构因子、材料参数、以及热变形激活能的6次多项式方程，从而建立了随材料参数变化的Cu—Ag合金流变应力本构模型。根据动态材料模型（DMM）建立功率耗散图和失稳图，并通过叠加得到Cu-Ag合金的热加工图，然后，利用热加工图确定了该合金的加工安全区和流变失稳区。分析可知Cu—Ag合金的最佳变形工艺参数主要处于3个区问：低温低应变速率区（变形温度为700—770℃，应变速率为0．0100～0．0316s^-1），该区域的峰值功率耗散系数叼为0．46；高温中应变速率区（变形温度为780～835℃，应变速率为0．1—1．0s^-1）。该区域的峰值功率耗散系数叼为0．33；和高温高应变速率区（变形温度为835—850℃，应变速率为3．162—10．0008^-1），该区域的功率耗散系数η峰值为0．33。
The hot flow stress behavior of Cu-Ag alloy was studied by hot compression tests at the strain rates of 0.01 - 10.00 s and the temperatures of 700 - 850℃. The results showed that the high-temperature flow stress of the alloy was sensitive to temperature and strain rate, and softening characteristics were different under the different conditions. Through hyperbolic sine constitutive equation and analysis of hnear regression,6 times polynomial equations under different deforming conditions were obtained about structure factor A, the material parameters a, n and the hot deformation activation energy Q. Thus, the flow stress constitutive equation of alloy was established. The processing map of Cu-Ay alloy was set up through the power dissipation map and instability map which were estab- lished based on the dynamic material modeling （DMM）. Then the processing zone and flow instability region based processing map were determined. The results showed that the optimal deformation parameters included three areas： the low temperature and low strain rate region （deformation temperature of 700 - 770 ℃, strain rate of 0.0100 - 0.0316 s^- 1 ）, in which the maximum power dissipation coefficient ηwas 0.46 ; high temperature and medium strain rate region （ deformation temperature of 780 - 835℃, strain rate of 0.1 - 1.0 s^-1 ）, in which the maximum power dissipation coefficient ηwas 0.33 ; and high temperature and high strain rate （ deformation temperature of 835 -850 ℃, strain rate of 3. 162 - 10.000 s-1 ）, in which the maximum power dissipation coefficient ηwas 0.33.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2013年第5期695-701,共7页
Chinese Journal of Rare Metals
基金
中央高校基本科研业务费(CDJZR11130003)资助项目
