A New Analytical Model for the Flow Stress of Twin-roll Casting Magnesium Sheet at Elevated Temperatures

• Published in: Journal of materials science & technology Vol. 26; no. 5; pp. 461 - 466
• Main Authors: Liu, Zhimin, Xing, Shuming, Bao, Peiwei, Li, Nan, Yao, Shuqing, Zhang, Milan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2010
• Subjects: Computer simulation; Curve fitting; Deformation; Deformation mechanisms; Dynamic recrystallization; Evolution; Flow stress; Forming; Grain size; Grains; High temperature; Magnesium; Mathematical analysis; Mathematical models; Microstructure; Semi-sold grains; Strain rate; Stress strain curves; Stress-strain relationships; Twin roll casting; Twinning; Volume fraction; Yield strength; 体积分数; 双辊铸造; 应力应变曲线; 曲线拟合; 流动应力; 解析模型; Twin-roll casting; Semi-sold grains; Twinning
• ISSN: 1005-0302; 1941-1162
• DOI: 10.1016/S1005-0302(10)60073-4

To evaluate the flow stress of the twin-roll casting magnesium sheet in high temperature forming processes,a new analytical model was proposed by analyzing stress-strain curves measured under various temperatures and strain rates.The model can be parameterized to reflect the volume fraction of semi-sold grain and sold grains undergoing twinning.By applying the new model,the result showed that the simulated stress-strain curves fit the experiment data very well.Such curve fitting can be employed for any magnesium sheet when the deformation conditions are known.Microstructure evolution indicated that it affected the stress-strain curves directly.The mechanisms of dynamic recrystallization（DRX） depended on the operating deformation mechanisms,which changed with temperatures.And the volume fraction and grain size of DRX changed with the Zener-Hollomon parameter and temperatures.