摘要
通过Ti-6Al-2Zr-1Mo-1V(TA15)合金多组试样热物理模拟压缩实验获得温度1073～1323K、应变速率0.01～10s-1下的真实应力-应变数据,以此作为计算应变速率敏感指数m、功率耗散系数η、失稳判据ξ三重指标的底层材料模型。以一组3D曲面形式揭示了应力、应变速率、温度、应变量的共同作用诱导的多种变形机制的转化及同时存在所引起的应变速率敏感系数m的剧烈响应,并通过m值的正负初步识别变形稳定区和失稳区。进一步绘制能量耗散图并识别出η值为负的不稳定变形区,以及η值为正的稳态变形区。在此基础上最后通过失稳判据分布图识别出ξ>0的稳定变形区、ξ≤0的失稳变形区。最后将不同应变下的功率耗散图和失稳图叠加以构造最终所需的含应变影响的系列加工图。综合识别后,具有较高m值水平、较高η值水平、较高ξ值水平的稳定变形参数区间为优先推荐,具有负m值水平、负η值水平、负ξ值水平的失稳变形参数区间为避免推荐。
Several series of billet samples were compressed on heat physical simulation machine under deformation temperatures 1073-1323K and strain rates 0.01-10s-1,then the true stress-strain data collected resulted the performance of calculations for strain rate sensitivity（m-value）,power dissipation efficiency（η-value） and instability parameter（ξ（ε·-value）.A series of 3D surfaces reveal the dramatic response of m-value to the transferring and coexisting of several deformation mechanisms induced by the enhanced effect of stress,temperature,strain rate and strain,from which the stable and unstable deformation parameter regions were indentified preliminarily.In further,the maps of power dissipation efficiency were plotted,from which the unstable（η≤0） deformation parameter regions were indentified furtherly.Finally,based on the map of instability criterion,stable region（ξ0）,unstable region（ξ≤0） were clarified clearly.According to the comprehensive identification,the stable deformation parameter regions with higher m-value level,higher η-value level,higher ξ-value level are recommended,while the unstable deformation parameter regions with negative m-value level,negative η-value level,negative ξ-value level should be avoided.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2011年第12期2301-2306,共6页
Journal of Functional Materials
基金
科技部国家重大专项资助项目(G09003.8-3)
中央高校基本科研业务费资助项目(CDJXS11131147)
关键词
钛合金
热压缩
动态材料模型
应变速率敏感指数
加工图
TA15 alloy
hot compression
dynamic materials model
strain rate sensitivity
processing map
