Abstract
Rare earth elements reportedly improve high temperature strength and creep resistance of Mg alloys. In the present work, ZK60 Mg alloys containing different amounts (0.5, 1.5 and 2.5 wt.%) of rare earth additions were prepared by thixocasting and submitted to solution and ageing heat treatments (T4, T5 and T6). The as-cast and heat treated microstructures were investigated by scanning electron microscopy and hardness was evaluated as a function of heat treatment parameters. In the as-cast state, the alloys are formed by globular α-Mg grains reinforced by a network of composite Mg-Zn-RE precipitates with either smooth or lamellar/acicular morphologies. Solution of the smooth precipitates took place in alloys containing 0.5 and 1.5wt.%RE for T4-500 ºC but no precipitates were dissolved with T4-380 ºC. The optimum temperature for T5 and T6 was identified as 175 ºC, while T6-500 ºC led to the highest hardness, followed by T5 and T6-380 ºC, respectively.
Original language | English |
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Pages (from-to) | 1507-1512 |
Journal | Materials Research |
Volume | 17 |
Issue number | 6 |
DOIs | |
Publication status | Published - 2014 |
Fields of Expertise
- Advanced Materials Science
Treatment code (Nähere Zuordnung)
- Basic - Fundamental (Grundlagenforschung)
- Experimental