Hot deformation behavior of mechanically alloyed Al6063/0.75Al₂O₃/0.75Y₂O₃ nano-composite鈥擜 study using constitutive modeling and processing map

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• 作者：Hafeez Ahamed ^{hafeez_ahamed@rediffmail.com} ; V. Senthilkumar ; ^{vskumar@nitt.edu}
• 关键词：Microstructure ; Nano-composites ; Mechanical alloying ; Processing maps
• 刊名：Materials Science and Engineering ; A
• 出版年：2012
• 期刊代码：61_09215093
• 类别：ms
• 出版时间：30 March, 2012
• 卷：539
• 期：Complete
• 页码：349-359
• 文件大小：2547 K

摘要

The hot deformation behavior of mechanically alloyed (MA鈥檈d) Al6063/0.75Al₂O₃/0.75Y₂O₃ nano-composite was characterized in the temperature and strain rate ranges of 300-500 掳C and 0.001-1 s^鈭? using compression test. Hot workability is interpreted by processing maps based on dynamic material modeling (DMM) and constitutive model was established based on sine-hyperbolic Arrhenius kinetic rate equation. Dynamic recrystallization (DRX) occurs in the temperature range of 400-500 掳C and strain rate range of 0.001-0.1 s^鈭?. The optimum processing parameters for hot working of MA鈥檈d Al6063/0.75Al₂O₃/0.75Y₂O₃ nano-composite was identified to be in two domains, viz.: (i) T = 395-440 掳C and and (ii) T = 440-500 掳C and respectively with maximum efficiency of about 37-39%respectively. At strain rates ranging from 0.1 to 1 s^鈭? the nano-composite exhibits flow instability for all temperatures investigated. The average apparent activation energy for hot deformation is calculated to be 181 kJ/mol and flow behavior of the material was styled through a constitutive model. The reasons for the flow instability have been observed to be the surface cracking, void formation, matrix cracking, pores and wedge cracking.