• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2019, Vol. 55 ›› Issue (18): 43-52,62.doi: 10.3901/JME.2019.18.043

• 材料科学与工程 • 上一篇    

Ti-6Al-4V钛合金薄板应力松弛行为研究

毕静1,2, 崔学习3, 张艳苓1,2,4, 张志1,2,4, 吴向东3   

  1. 1. 中国航空制造技术研究院 北京 100024;
    2. 中国航空制造技术研究院塑性成形技术航空科技重点实验室 北京 100024;
    3. 北京航空航天大学机械工程及自动化学院 北京 100191;
    4. 中国航空制造技术研究院数字化塑性成形技术及装备北京市重点实验室 北京 100024
  • 收稿日期:2019-01-03 修回日期:2019-06-05 发布日期:2020-01-07
  • 通讯作者: 吴向东(通信作者),男,1970年出生,博士,副教授,硕士研究生导师。主要研究方向为塑性成形理论、工艺与装备技术。E-mail:wuxiangdongbuaa@163.com
  • 作者简介:毕静,女,1988年出生,工程师。主要研究方向为金属热冲压成形。E-mail:475912215@163.com
  • 基金资助:
    国家自然科学基金(51875027)和中国航空制造技术研究院资助项目。

Investigations on Stress Relaxation Behavior of Ti-6Al-4V Titanium Alloy Thin Sheet

BI Jing1,2, CUI Xuexi3, ZHANG Yanling1,2,4, ZHANG Zhi1,2,4, WU Xiangdong3   

  1. 1. AVIC Manufacturing Technology Institute, Beijing 100024;
    2. Aeronautical Key Laboratory for Plastic Forming Technology, AVIC Manufacturing Technology Institute, Beijing 100024;
    3. School of Mechanical Engineering and Automation, Beihang University, Beijing 100191;
    4. Beijing Key Laboratory of Digital Forming Technology and Equipment, AVIC Manufacturing Technology Institute, Beijing 100024
  • Received:2019-01-03 Revised:2019-06-05 Published:2020-01-07

摘要: 针对Ti-6Al-4V钛合金薄板,分别在温度650℃、700℃和750℃,和预应变2%、4%和16%的条件下进行多组应力松弛交叉试验。研究Ti-6Al-4V钛合金高温下的应力松弛行为及温度和预应变对应力松弛极限的影响。并基于试验数据,对比分析阶次不同的延迟函数的拟合精度,最终采用精度更高的四次延迟函数进行Ti-6Al-4V钛合金的应力松弛曲线拟合。通过对比发现四次延迟函数预测的结果和试验数据十分吻合,并且拟合最低精度高达99.724%,证明使用四次延迟函数拟合应力松弛曲线的有效性。在试验数据的基础上,进一步推导出高温短时蠕变应变速率与应力的关系。最后基于Arrhenius本构模型,通过对各参数的线性回归,建立适合Ti-6Al-4V钛合金薄板的高温短时蠕变型本构方程,为后续热校形工艺制定和数值模拟奠定基础。

关键词: 钛合金薄板, 应力松弛, 松弛极限, 延迟函数, 蠕变型本构模型

Abstract: The multiple sets of stress relaxation crossover tests of the Ti-6Al-4V titanium alloy ultrathin sheet with the different temperatures (650℃, 700℃ and 750℃) and the different pre-strain (2%, 4% and 16%) are carried out. The effects of temperature and pre-strain on the stress relaxation resistance of Ti-6Al-4V titanium alloy and the stress relaxation behavior at high temperature are investigated. Based on the experimental data,the stress relaxation curve fitting of Ti-6Al-4V titanium alloy is carried out with a more accurate four-order delay function. The results of the four-time delay function prediction are in good agreement with the experimental data,and the fitting accuracy is as high as 99.724%. Based on the experimental data,the relationship between the short-term creep strain rate and stress at high temperature is further derived. Finally,based on the Arrhenius constitutive model,the high-temperature short-time creep constitutive equation of Ti-6Al-4V titanium alloy ultrathin sheet is established,which laid a foundation for subsequent hot sizing process formulation and numerical simulation.

Key words: titanium alloy thin sheet, stress relaxation, relaxation resistance, delay function, creep-type constitutive model

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