摘要
对TA2纯钛板辊弯成形回弹显微机理进行了系统研究,采用辊弯成形工艺对TA2纯钛板进行了单道次及多道次不同设计角度的冷变形加工。首先,研究了不同设计角度辊弯成形板材的回弹规律,其次,利用显微硬度计测试了辊弯成形样品的显微硬度变化,最后,通过电子背散射衍射实验研究了TA2辊弯成形板材的显微组织、织构和取向差的演变规律。结果表明,在单道次辊弯成形实验中,随着设计角度的增大,回弹逐渐减小,显微硬度逐渐增大,主要原因是孪生参与协调塑性变形,织构强度逐渐增大,变形量增大导致位错密度降低。在终设计角度为30°的辊弯成形实验中,随着道次数的增加,回弹逐渐增大,而显微硬度逐渐降低,孪生现象消失,织构强度逐渐降低,位错密度逐渐增大,这是由变形量递增,反复加载卸载后通过位错滑移产生的弹性回复逐渐增大导致的,这是由辊弯成形所特有的工艺特点决定的。
The microscopic mechanism of roll forming springback of TA2 pure titanium sheet was systematically studied,and the single-pass and multi-pass cold deformation processing with different design angles of TA2 pure titanium sheet were carried out by means of roll forming process.Firstly,the springback law of roll forming sheet with different design angles was studied.Secondly,the microhardness change of roll forming specimens was tested by microhardness equipment.Finally,the evolution law of microstructure,texture and misorientation was studied by electron back-scattered diffraction(EBSD)experiments.The results show that in the single-pass roll forming experiments,with the increase of design angle,the springback gradually decreases,and the microhardness gradually increases.The main reason is that twinning participates in the coordination of plastic deformation,the texture strength gradually increases,and the increase of deformation amount leads to the decrease of dislocation density.In the roll forming experiments with final design angle of 30°,with the increase of pass number,the springback gradually increases,while the microhardness gradually decreases,the twinning phenomenon disappears,the texture strength gradually decreases,and the dislocation density gradually increases,which is caused by the gradual increase of elastic recovery generated by dislocation slip after repeated loading and unloading with the gradual increase of deformation amount,and that is determined by the unique process characteristics of roll forming.
作者
韩飞
辛柏朴
孟伊帆
HAN Fei;XIN Bai-pu;MENG Yi-fan(College of Mechanical and Materials Engineering,North China University of Technology,Beijing 100144,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2023年第2期26-33,共8页
Journal of Plasticity Engineering
基金
北京市自然科学基金-市教委联合资助项目(KZ201910009011)
北京市属高校高水平教师队伍建设长城学者培养计划(CIT&TCD20190306)
国家自然科学基金资助项目(51074204)
北京市教委基本科研业务费项目(110052972027/024)
北方工业大学毓杰团队支持计划(107051360021XN083/001)。
关键词
辊弯成形
回弹
微观组织
织构
roll forming
springback
microstructure
texture
