Fracture behaviors of AZ80 magnesium alloy during multiple forging processes

• Published in: Transactions of Nonferrous Metals Society of China Vol. 16; no. 4; pp. 922 - 926
• Main Author: 郭强 严红革 陈振华 张辉
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2006; School of Materials Science and Engineering, Hunan University, Changsha 410082, China
• Subjects: AZ80 magnesium alloy; AZ80合金; cracks; fracture behaviors; multiple forging; 热加工; 镁合金; fracture behaviors; AZ80 magnesium alloy; cracks; multiple forging
• ISSN: 1003-6326
• DOI: 10.1016/S1003-6326(06)60352-X

The initiation, propagation and the accompanied dislocation structures of the cracks in AZ80 magnesium alloy during multiple forging processes were investigated. The results show that the cracks firstly initiate at the Mg/Mg17Al12 interface under the hoop tensile stress on equatorial free surface. On further deformation, the cracks in the Mg17Al12 particles tend to propagate along the grain boundaries（GBs） in a zigzag pattern and link with adjacent cracks in other Mg17Al12 particles to form one whole crack, leading to the fracture surface. Low deformation temperature and too many forging passes during the deformation will promote the nucleation of interfacial microcrack inside the specimens due to the strong plastic strain incompatibility and the high internal stresses near the GBs. The loading axis rotating during the process can change the stress field at the tip of cracks, leading to the change of the crack propagating path and assisting in inhabiting microcracking development.