Effects of Mn addition and related Mn-containing dispersoids on the hot deformation behavior of 6082 aluminum alloys

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:764

Article

Qian, Xiaoming¹  Parson, Nick²  Chen, X. -Grant¹ 

[1] Univ Quebec Chicoutimi, Dept Appl Sci, Saguenay, PQ G7H 2B1, Canada

[2] Arvida Res & Dev Ctr, Saguenay, PQ G7S 4K8, Canada

关键词: 6082 aluminum alloy;    Mn addition;    Dispersoids;    Hot deformation;    Activation energy;    Dynamic recovery and recrystallization;   

DOI  :  10.1016/j.msea.2019.138253

来源: Elsevier

【 摘 要 】

The hot deformation behaviors of 6082 aluminum alloys containing different Mn contents (0.05-1.0 wt%) were systematically investigated by uniaxial compression tests in a temperature range of 400-550 degrees C and strain rate range of 0.001-1 s(-1). Prior to the hot deformation, a low-temperature homogenization (450 degrees C for 6 h) was carried out on direct-chill cast billets to promote the precipitation of Mn-containing dispersoids. The large numbers of dispersoids in the Mn-containing alloys yielded significantly increased high-temperature flow stresses, compared to that of the base alloy without dispersoids. The material constants and activation energies for hot deformation were determined using the hyperbolic-sine constitutive equation and experimental peak flow stress data. The activation energy increased from 191 kJ/mol for the base alloy to 286 kJ/mol for the alloy with 0.5% of Mn. With further increase in Mn content, the activation energy increased only moderately to 315 kJ/mol for the alloy with 1.0% of Mn. The influences of the Mn content and deformation conditions on the dynamic recovery and recrystallization were quantitatively analyzed. The precipitation of dispersoids in the Mn-containing alloys promoted the retardation of the dynamic recovery and inhibition of the recrystallization owing to their strong pinning effect on the dislocation movement and subgrain migration.

【 授权许可】

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