Effect of Homogenization Treatment and Microalloying with Mn on the Microstructure and Hot Workability of AA6060 Aluminum Alloys

Journal Article · Thu Aug 15 04:00:00 EDT 2019 · Journal of Materials Engineering and Performance

DOI:https://doi.org/10.1007/S11665-019-04232-7· OSTI ID:22970554

Qian, Xiaoming ^[1]; Parson, Nick ^[2]; Chen, X. -Grant ^[1]

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1. University of Quebec at Chicoutimi, Department of Applied Sciences (Canada)
2. Rio Tinto, Arvida Research and Development Centre (Canada)

The effects of a homogenization treatment and microalloying with Mn on the evolution of the microstructure and hot workability of AA6060 aluminum alloys were investigated. Various homogenization treatments with temperatures ranging from 520 to 610 °C and soaking times from 2 to 16 h were conducted. The results revealed that β-AlFeSi intermetallic was the dominant phase in the as-cast microstructure of the experimental alloys. During the homogenization, the fragmentation of intermetallics occurred and plate-like β-AlFeSi transformed into rod-like α-AlFeSi. In addition, a number of dispersoids precipitated in the 0.1Mn alloy in the temperature range of 520-580 °C. The flow stress behavior of the homogenized AA6060 alloys was mainly determined by the solid solution level. Increasing homogenization temperatures resulted in higher flow stresses owing to the increase in solute atoms in the aluminum matrix. The incremental Mn addition from 0 to 0.1% moderately increased the flow stress by up to 3%. Grain growth occurred in the alloys with low Mn contents (< 0.03Mn) during the high-temperature homogenization (580-610 °C), which resulted in a sudden decrease in the flow stresses and an irregular sample shape after the deformation. Microalloying with Mn (> 0.06%) can effectively prevent grain growth at such temperatures. For an alloy with Mn (0.1%) microalloying, homogenization at 550-580 °C for 6 h could be the optimal condition to balance the flow stress and desirable microstructure.

• OSTI ID: 22970554
• Journal Information: Journal of Materials Engineering and Performance, Journal Name: Journal of Materials Engineering and Performance Journal Issue: 8 Vol. 28; ISSN 1059-9495; ISSN JMEPEG
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
CRYSTAL LATTICES
FLOW STRESS
GRAIN GROWTH
INTERMETALLIC COMPOUNDS
MICROSTRUCTURE
NANOSTRUCTURES
SOLID SOLUTIONS