Ti6213合金的热加工图研究

在Gleeble-1500热模拟机上进行了Ti6213合金热模拟压缩试验,变形温度范围为800-1050℃,应变速率范围为0.001-10 s-1,最大变形量为60%,并根据动态材料模型建立了加工图。结果表明,合金在高温变形时主要有2个合适的加工区域,一个是变形温度800-950℃,应变速率0.01 s-1以下区域;另一个在相变温度以下40℃内,应变速率10 s-1以上区域。在900-930℃和0.001 s-1的变形条件下,出现耗散率峰值为65%,高m值,S形应力和应变速率对数曲线的现象,合金表现出超塑特性。拉伸实验进一步表明,延伸率可达512%,组织为两相混合组织。另外,合金在800-930℃和大于0.01 s-1的条件下出现集中变形带,表现为局部流变特征。

Processing Map for Hot Working of Ti6213 Titanium Alloy

The isothermal compression of Ti6213 alloy was carried out on a Gleeble-1500 simulator at temperature 800-1050℃ with strain rate of 0.001-10s-1 and maximum deformation of 60%.Processing and instability maps were developed for the alloy based on dynamic material,which presents two suitable process zones including the zone 800-950℃ of deformation temperature with strain rate 0.01 s-1,and another zone 40℃ lower than the alloy′s β-transus temperature with strain rates over 10 s-1.The alloy exhibits superplasticity with a peak efficiency of 65%,higher strain-rate sensitivity and sigmoidal variation between log flow stress and log strain rate at 900-930℃ and 0.001s-1.Tensile test shows that elongation can reach 512%,with two-phase duplex structure.The material also exhibits flow localization due to deformation band at 800-930℃ with strain rates over 0.01s-1.