摘要
采用Gleeble-3800热力模拟试验机在温度为200～350℃,应变速率为0.001～1s^(-1)时对等径角挤压制备的Mg-4Zn合金进行压缩试验,利用双曲正弦本构关系式计算变形激活能。结果表明,Mg-4Zn合金热变形激活能随应变的增加而增加。变形初期的率控制机制为晶格自扩散,而变形后期为位错交滑移。根据动态材料模型,建立了Mg-4Zn合金的加工图。由于变形后期非基面滑移和位错交滑移的启动促进了动态再结晶过程,使得失稳区的面积随应变增加而减小。可加工区间温度位于260～350℃,应变速率在0.01～0.1s^(-1)范围内。
Hot compression tests of equal channel angular pressed Mg-4Zn alloy were conducted on a Gleeble-3800 thermal-mechanical simulator at 200~350℃and 0.001~1 s^-1.The deformation activation energy(Q)was calculated using a hyperbolic sine constitutive equation.The results show that Qis increased with strain increase.At the beginning of deformation,the rate controlling process is characterized by lattice self-diffusion controlled.At the late stage of deformation,the rate controlling mechanism is characterized by the cross-slip of dislocations.Based on the dynamic material model,the processing maps of Mg-4Zn alloy were established.The areas of the instability domains are decreased with increasing in strain since the initiation of non-basal slips and cross-slip enhancing the dynamic recrystallization process.Workability domain occurs at 260~350℃and 0.01~0.1 s^-1.
作者
李南南
骆晓东
Li Nannan;Luo Xiaodong(College of Mechanical Engineering,Yangzhou University)
出处
《特种铸造及有色合金》
CAS
北大核心
2019年第2期220-224,共5页
Special Casting & Nonferrous Alloys
基金
扬州大学研究生国际学术交流专项基金资助项目
关键词
率控制机制
可加工性
加工图
等径角挤压
镁合金
Rate Controlling Mechanism
Workability
Processing Map
Equal Channel Angular Pressing
Magnesium Alloy
