摘要
在室温下对TA2纯钛进行不同加载工况(不同应力水平、不同应力速率下的拉-压和拉-拉循环,拉-压保载循环,变应力4级加载)下的单轴非对称应力控制循环变形试验以及蠕变-循环变形交替试验,研究了应力水平、应力速率、峰/谷值应力保持时间和保持形式以及加载历史对棘轮行为的影响。结果表明:TA2纯钛的棘轮行为具有明显的时间相关性。棘轮应变和应力-应变滞回环面积均随着应力速率降低而增大;只有峰值应力保持工况的棘轮应变高于峰/谷值应力同时保持的工况,且保持时间越长,棘轮应变越大。先蠕变后循环变形与先循环变形后蠕变的最终峰值应变接近且均低于具有峰值应力保持的工况,说明蠕变和棘轮的交替进行会促进塑性变形。
Uniaxial asymmetric stress controlled cyclic deformation tests under different stress loading conditions(tension-tension and tension-compression cycle under different stress levels and different stress rates,tensioncompression load-holding cycle and variate stress four-level loading)and creep-cyclic deformation alternating tests were conducted on TA2 pure titanium at room temperature.The effects of stress level,stress rate,peak/valley stress holding time and holding form and loading history on ratcheting behavior of TA2 pure titanium were studied.The results show that the ratcheting behavior of TA2 pure titanium exhibited obvious time dependence.Both the ratcheting strain and the area of stress-strain hysteresis loop increased with the decrease of stress rate.The ratcheting strain under the condition of peak stress holding was higher than that under the condition of both peak and valley stress holding,and the longer the holding time was,the greater the ratcheting strain.The final peak strains after creep followed by cyclic deformation and after cyclic deformation followed by creep were similar and lower than those under conditions of peak stress holding,indicating that the alternating creep and ratcheting promoted the plastic deformation.
作者
李琦
陈开卷
石文翔
阚前华
康国政
LI Qi;CHEN Kaijuan;SHI Wenxiang;KAN Qianhua;KANG Guozheng(School of Mechanics and Aerospace Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《机械工程材料》
北大核心
2025年第2期9-15,111,共8页
Materials For Mechanical Engineering
基金
国家重点研发计划项目(2022YFB3401901)。
关键词
TA2纯钛
棘轮
时间相关
蠕变-棘轮交互作用
加载历史
TA2 pure titanium
ratcheting
time dependence
creep-ratcheting interaction
loading history
