| 引用本文: | 刘俊雄,吴向东,万敏,李志燕.基于修正的Arrhennius方程钛合金高温本构方程研究[J].材料科学与工艺,2015,23(3):7-11.DOI:10.11951/j.issn.1005-0299.20150302. |
| LIU Junxiong,WU Xiangdong,WAN Min,LI Zhiyan.Study on hot deformation behavior of titanium alloy by modified Arrhennius equation[J].Materials Science and Technology,2015,23(3):7-11.DOI:10.11951/j.issn.1005-0299.20150302. |
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| 摘要: |
| 为了更准确地描述钛合金的高温变形行为,对Arrhennius方程进行修正得到钛合金高温本构方程.通过对一种新型钛合金在热模拟试验机上进行恒应变速率等温压缩实验,研究其在700～1 000 ℃、应变速率0.01～10 s-1条件下的热变形行为,分析了材料的真实应力-真实应变曲线.采用最小二乘拟合的数据回归处理,得到该钛合金在α+β双相区和β单相区的热变形激活能,并通过引入温度变量,获得了Arrhennius方程参数A随温度变化的函数关系,建立了该材料的高温流变应力本构方程.实验结果表明,随着变形增加,流变应力开始急剧增加,随后出现软化并趋于稳态,同时峰值应力对于温度和应变速率具有很强的敏感性.通过在Arrhenius方程中引入温度变量,有利于提高本构方程的准确性. |
| 关键词: 钛合金 高温成形 本构方程 最小二乘拟合 Arrhenius方程 |
| DOI：10.11951/j.issn.1005-0299.20150302 |
| 分类号:TG319 |
| 基金项目: |
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| Study on hot deformation behavior of titanium alloy by modified Arrhennius equation |
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LIU Junxiong1,WU Xiangdong1,WAN Min1,LI Zhiyan2
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(1.School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, China; 2.School of Material Science & Engineering, Beihang University, Beijing 100191, China)
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| Abstract: |
| Arrhennius equation was modified to obtain a more accurate description of the hot deformation behavior of Titanium alloy. Based on the results that the constant strain rate and isothermal compression experiment for a new type of titanium alloy was performed on thermal simulation testing machine, hot deformation behavior was studied at temperatures of 700～1 000 ℃and strain rates of 0.01～10 s-1. Using the least square fitting method, the activation energy in α+β and β phase areas was calculated. The constitutive equation of flow stress was obtained by introducing function of parameter Aof the Arrhennius equation and temperature .The analysis of the true stress-true strain curves shows that the flow stress sharply increased firstly, then decreased to a steady state. The peak stress is both sensitive to temperature and strain rate. The experiments show that the modified Arrhenius equation improves the accuracy. |
| Key words: titanium alloy hot forming constitutive equation least square fitting Arrhennius equation |
