摘要
采用Sans CMT4104型拉伸试验机对2060铝锂合金进行分步超塑性拉伸试验,研究该合金在变形温度为425~500℃和预应变量为10%~30%条件下的超塑性和显微组织演变。结果表明,分步拉伸试样的伸长率随着温度的升高而上升,随着预应变量的增加先上升后下降,450~500℃内其伸长率均大于单步拉伸试样。在变形温度为500℃、预应变量为20%条件下合金超塑性最佳,伸长率达到211%。分步拉伸时的间隙保温导致流变应力下降,下降程度随着预应变量的增加而变大,随着温度的升高先变大后减小;第二步拉伸时的峰值应力较单步拉伸的峰值应力明显减小。显微组织观察发现,合金在425℃时出现大量弥散相,在450℃时弥散相溶于基体中,晶界局部呈锯齿状,475~500℃时基体中出现三角状第二相,存在较多动态再结晶晶粒。
The multi-step superplasticity tests of 2060 Al-Li alloy were carried out by using SANS CMT4104 tensile testing machine.The microstructure evolution and superplasticity properties of 2060 Al-Li alloy were investigated at deformation temperature of 425~500℃and prestrain of 10%to 30%.The results indicate that the elongation of the multi-step tensile specimen is increased with the increase of temperature,and increased firstly and then decreased with the increase of prestrain,which is greater than that of the single-step tensile specimen in the range of 450~500℃.The superplasticity is desirable when the deformation temperature is 500℃and the prestrain is 20%,and the elongation reaches 211%.The interstitial insulation during multi-step tensile process leads to the decrease of flow stress,of which the degree is increased with the increase of the prestrain,and increased firstly and decreased with the increase of temperature.The peak stress at the second step tensile process is decreased significantly compared to that at single-step tensile process.The microstructure of the alloy reveals that a large number of dispersive phases appear at 425℃,and then dissolved into the matrix at 450℃with zigzagshaped grain boundary.During 475℃to 500℃,the triangular second phase emerges in the matrix with a large number of dynamic recrystallized grains.
作者
于以标
陈乐平
徐勇
袁源平
方森鹏
Yu Yibiao;Chen Leping;Xu Yong;Yuan Yuanping;Fang Senpeng(School of Aeronautical Manufacturing Engineering,Nanchang Hangkong University;National Defense Key Discipline Laboratory of Light Alloy Processing Science and Technology,Nanchang Hangkong University)
出处
《特种铸造及有色合金》
CAS
北大核心
2022年第3期366-370,共5页
Special Casting & Nonferrous Alloys
基金
航空科学基金资助项目(2019ZE056009)
江西省重点研发计划资助项目(20202BBEL53012)
轻合金加工科学与技术国防重点学科实验室开放基金资助项目(EG201903175)。
关键词
分步超塑性
铝锂合金
显微组织
Multi-step Superplasticity
Al-Li Alloy
Microstructure
