摘要
采用Gleeble-3800热模拟试验机对Ti2041合金进行等温恒应变速率压缩实验,研究其在变形温度为650~900℃、应变速率为0.001~1.000 s^(-1)和最大变形量为60%下的高温热变形行为。分析了不同变形工艺参数对微观组织的影响规律。结果表明:合金的峰值应力值随着应变速率的增大而增大,随着变形温度的升高而降低。随着变形温度、应变速率和变形量的增大,变形组织中的动态再结晶现象越明显,晶粒尺寸逐渐减小,合金的显微硬度逐渐增大。通过提高变形温度、增大应变速率和变形量达到了细化晶粒的效果;随着保温时间的增加,晶粒尺寸越大,合金的显微硬度值也逐渐降低。基于实验数据,建立了含Z参数的应变补偿Arrhenious本构方程,具有较高的精度,其相关系数值达到了0.99295,平均相对误差为7.63%,预测值偏差在15%以内的数据点达92.82%。
The isothermal constant strain rate compression test of Ti2041 alloy was carried out by Gleeble-3800 thermomechanical simulator.The high temperature hot deformation behavior was studied at 650~900℃,0.001~1.000 s^(-1) and deformation degree of 0.6.The influence of different deformation parameters on the microstructure was analyzed.The results showed that the peak stress value of the alloy increased with the increase of strain rate,and decreased with the increase of deformation temperature.Dynamic recrystallization occurred in the structure at low strain rate(0.001,0.010 s^(-1)),which existed in the form of equiaxed grains.The reason was that when the alloy deformed at low strain rate,the deformation time was longer and the recrystallized grain grew.At 0.100 s-1,recrystallized grain occurred at the grain boundary.As the strain rate increased(1.000 s^(-1)),the grains were severely deformed and presented streamlined distribution.Due to the increase of strain rate,the alloy had no-enough time to produce dynamic recrystallization,and the internal stress generated in the process of hot compression could not be eliminated,resulting in severe deformation of grains.The microhardness value increased and the maximum value was HV 322.6.Increasing the deformation temperature,the degree of recrystallization of the alloy increased,and the microhardness value gradually increased,with the maximum value reaching HV 314.3.When the deformation temperature was lower,the primaryαphase existed in the microstructure,resulting in low microhardness.With the increase of deformation temperature,recrystallized grains appeared at grain boundary,and dynamic recrystallization phenomenon occurred in the structure and the grain size decreased,leading to the increase of microhardness value.With the increase of deformation amount,dynamic recrystallization phenomenon became more obvious and the grain size gradually decreased.The reason was that when the amount of deformation was lower(20%),the distortion energy and dynamic recrystallization drivin
作者
周璇
王克鲁
鲁世强
李鑫
Zhou Xuan;Wang Kelu;Lu Shiqiang;Li Xin(School of Aeronautical Manufacturing Engineering,Nanchang Hangkong University,Nanchang 330063,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2022年第5期554-563,共10页
Chinese Journal of Rare Metals
基金
国家自然科学基金项目(51464035)资助。
关键词
Ti2041合金
热变形
动态再结晶
本构模型
Ti2041 alloy
hot deformation
dynamic recrystallization
constitutive model
