Dislocation mechanism for dynamic recrystallization in twin-roll casting Mg-5.51Zn-0.49Zr magnesium alloy during hot compression at different strain rates

作者：Liu, Zhi-yi^*; Huang, Tian-tian; Liu, Wen-juan; Kang, Sukbong

来源：Transactions of Nonferrous Metals Society of China, 2016, 26(2): 378-389.

DOI：10.1016/S1003-6326(16)64126-2

• magnesium alloy
• dislocation
• mechanism
• dynamic recrystallization

Dislocation mechanism operating in dynamic recrystallization (DRX) during hot compression of Mg-5.51Zn-0.49Zr alloy was investigated by X-ray diffraction, optical microscopy and transmission electron microscopy. The results showed that the continuous DRX occurred at a low strain rate of 1x10(-3) s(-1), which was associated with the operation of the single gliding dislocation climbing. At the intermediate strain rate of 1x10(-2) s(-1), the continuous DRX was associated with the climbing of the gliding dislocation array as deformed at an elevated temperature of 350 degrees C, and in contrast, the discontinuous DRX was observed and associated with the bulging of subgrain boundaries as the deformation temperature was raised to 400 degrees C. The continuous DRX was associated with the climbing of the leading dislocation ahead of pile-ups, and resultant rearrangement of misorientated flat dislocation pile-ups as the strain rate was increased to 1x10(0) s(-1). It is suggested that the mechanism predominating the dislocation climbing was changed from the vacancy migration to the stress acting on the leading dislocation ahead of the pile-up as the strain rate was gradually increased.

• 出版日期2016-2
• 单位中南大学