Superplastic Deformation under Complex Loading Conditions

• Published in: Metals and materials (Seoul, Korea) Vol. 4; no. 4; pp. 891 - 894
• Main Authors: Tokuda, M., Inaba, T., Ide, A., Gong, C-B, Ye, M., Hu, R-C, Bundara, B.
• Format: Journal Article
• Language: Korean; English
• Published: Seoul 대한금속재료학회 01.01.1998; Springer Nature B.V
• Subjects: Axial forces; Axial stress; Combined loading; complex loading; Deformation mechanisms; Grain boundary sliding; High temperature; initial yield surface; Room temperature; Studies; Superplastic deformation; Superplasticity; Temperature
• ISSN: 1598-9623; 1225-9438; 2005-4149
• DOI: 10.1007/BF03026418

The initial yield surface of a superplastic material was investigated by using a combined loading of axial force and torque. The thin-walled tubular specimen made of Zn-22 wt.%Al alloy was used in the ex­perimental part of this study. Tests were carried out at room temperature (293 K) and at elevated tem­perature (523 K). The experimental results show that the material tested did not deform superplastically at 293 K exhibiting a yield surface that can be described by the second invariant of stress deviator (by Mises` criterion). On the other hand, the material was found to deform superplastically at the higher temperature of 523 K with a yield surface more complex compared to that observed at 293 K. This difference may be at­tributed to the difference in major deformation mechanism at two applied temperatures; that is, the slip within the grains at 293 K and the grain boundary sliding at 523 K.