摘要
采用Gleeble-3500热模拟机在变形温度为973~1273 K、应变速率为0.001~0.1 s^(-1)、真应变为60%的实验条件下,对预变形Mo-0.3La合金的热变形行为进行了研究,并采用包含Zene-Hollomon参数的双曲正弦模型,建立了热变形流变方程。结果表明:预变形Mo-0.3La合金的真应力-应变曲线具有动态再结晶特征,在较低的温度(973 K)/较高的应变速率(0.1 s^(-1))下,表现出加工硬化,在1273 K低应变速率(0.001和0.005 s^(-1))下动态再结晶具有显著性;合金含有31.65%大角度晶界,再变形后大角度晶界减少至17.14%,且存在少量的再结晶晶粒(6.08%);变形温度升高,大角度晶界和再结晶晶粒增多;由流变方程得到平均变形激活能Q为287.08 k J/mol,应力指数n为14.40,依据流变方程计算出的应力理论值与实际值的平均相对误差仅3.25%。
The hot deformation behavior of pre-deformed Mo-0.3La alloy was studied on the Gleeble-3500 thermal-mechanical simulatorat 973–1273 K with the deformation rate of 0.001–0.1 s^(-1)and the true strain of 60%,and the constitutive equation was establishedbyhyperbolic sine model with Zene-Hollomon parameter.The results show that the dynamic recrystallization characteristics of thetruestress-true strain curves are observed.Pre-deformed Mo-0.3La alloy exhibits work hardening at high strain rate of 0.1 s^(-1)or lowtemperature of 973 K,and dynamic recrystallization is significant at low strain rate of 0.001 and 0.005 s^(-1)at 1273 K.The high anglegrainboundary of the pre-deformed alloy is 31.65%.After redeformation,the high grain boundary fraction decreases to 17.14%withfewrecrystallized grains(6.08%).With the increase in deformation temperature,the fraction of high angle grain boundaries and recrystallizedgrains increases.Calculated by the constitutive equation,the deformation activation energy Q is 287.08 kJ/mol,and the stress exponent nis14.40.The average relative error between the theoretical stress calculated by the constitutive equation and experimental results is only 3.25%.
作者
张晓
任宝江
冯鹏发
安耿
卜春阳
胡平
席莎
李晶
周莎
王快社
Zhang Xiao;Ren Baojiang;Feng Pengfa;An Geng;Bu Chunyang;Hu Ping;Xi Sha;Li Jing;Zhou Sha;Wang Kuaishe(College of Metallurgical Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;National and Local Joint Engineering Research Center for Functional Materials Processing,Xi’an University of Architecture andTechnology,Xi’an 710055,China;Jinduicheng Molybdenum Co.,Ltd,Xi’an 710077,China;Shaanxi“Four Bodies and One Union”University-Enterprise Joint Research Center for Advanced Molybdenum-based Functional Materials,Xi’an 710077,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2024年第12期3390-3397,共8页
Rare Metal Materials and Engineering
基金
陕西省科技重大专项(2020zdzx04-02-01)
陕西省青年科技新星项目(2019KJXX-005)。
