Modification of magnesium alloys by ceramic particles in gravity die casting

A critical drawback for the application of magnesium wrought alloys is the limited formability of semifinished products that arises from a strong texture formation during thermomechanical treatment. The ability of second phase particles embedded into the metal matrix to alter this texture evolution is of great interest. Therefore, the fabrication of particle modified magnesium alloys (particle content 0.5–1 wt.-%) by gravity die casting has been studied. Five different types of micron sized ceramic powders (AlN, MgB2, MgO, SiC, and ZrB2) have been investigated to identify applicable particles for the modification. Agglomeration of the particles is revealed to be the central problem for the fabrication process. The main factors that influence the agglomerate size are the particle size and the intensity of melt stirring. Concerning handling, chemical stability in the Mg-Al-Zn alloy system, settling and wetting in the melt, and formation of the microstructure in most cases, the investigated powders show satisfying properties. However, SiC is chemically unstable in aluminum containing alloys. The high density of ZrB2 causes large particles to settle subsequent to stirring resulting in an inhomogeneous distribution of the particles over the cast billet.

Schlagworte

magnesium wrought alloys

gravity die casting

DDC Class

530: Physik

More Funding Information

German Research Foundation (DFG) in
the priority program SPP 1168 “InnoMagTec.”

Lizenz

https://creativecommons.org/licenses/by/3.0/

Name

IJMET.2014.748595.pdf

Size

3.93 MB

Format

Adobe PDF

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Modification of magnesium alloys by ceramic particles in gravity die casting