摘要
以TC4钛合金实际温镦成形工艺为研究对象,开展了400~800℃条件下不同变形程度的温镦试验,重点研究了不同变形温度与变形程度对温镦后变形区微观组织演化及绝热剪切行为的影响。通过对温镦后TC4钛合金试件的宏观开裂、内部微裂纹以及绝热剪切带特征的综合分析,确定了TC4钛合金的温镦成形工艺窗口。结果表明,绝热剪切带是TC4钛合金温镦成形中发生失稳开裂的关键前兆特征,温度为400~550℃、镦粗变形程度为60%~83%是发生开裂的高度敏感区;同时,该温度区间内试样更易出现鼓出不连续和形状不对称,进一步促进绝热剪切带开裂倾向。为降低开裂风险,多工位温镦的大变形阶段宜在700~800℃范围内完成。
Taking the industrial warm upsetting process of TC4 titanium alloy as the research subject,warm upsetting tests were conducted at 400-800℃with varying deformation degrees to investigate the effects of different deformation temperatures and deformation degrees on the microstructural evolution and adiabatic shear behavior in the deformed regions after warm upsetting.By comprehensively analyzing the macroscopic cracks,internal microcracks and adiabatic shear bands characteristics of the TC4 titanium alloy specimens after warm upsetting,the process window for TC4 warm upsetting was determined.The results indicate that adiabatic shear bands are the key precursor feature leading to instability and cracking during TC4 warm upsetting,acting as a highly sensitive zone for cracking at 400-550℃and upsetting deformation of 60%-83%.Meanwhile,specimens within such temperature range are more prone to discontinuous bulging and geometric asymmetry,which further promotes the cracking tendency in adiabatic shear band.To reduce the risk of cracking,large deformation stages in multi-stage warm upsetting should be performed within 700-800℃.
作者
刘佳琪
梁祥瑞
李想
胡成亮
LIU Jia-qi;LIANG Xiang-rui;LI Xiang;HU Cheng-liang(School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 201100,China;Beijing Shouhang Science and Technology Development Co.,Ltd.,Beijing 100000,China)
出处
《塑性工程学报》
北大核心
2026年第3期24-31,共8页
Journal of Plasticity Engineering
基金
国家高质量专项(2023ZY02012)。
关键词
温镦成形
TC4钛合金
绝热剪切带
微观组织
开裂
warm upsetting
TC4 titanium alloy
adiabatic shear bands
microstructure
cracking
