Microstructural characterisation and mechanical properties of the cast Gd-containing Mg−8Mg₂Si in situ composites

Abstract

Cast Mg–8 wt% Mg₂Si in situ composites containing 0, 0.5, 1, 2 and 3 wt% Gd were studied for their microstructure and high-temperature behaviour. Mechanical properties of the composites were investigated in the temperature range 25–250°C. Gd addition resulted in the modification of the primary Mg₂Si particles, reduction of their average size and volume fraction, and formation of new Mg₃Si₂Gd₂ and Mg₅SiGd intermetallic phases and solid solution of Gd in the Mg matrix. The composite with 1% Gd addition showed the highest strength due to the presence of finer Mg₂Si particles with polygonal morphology. Higher Gd contents decreased the strength, due to the coarsening of the Mg₂Si particles, caused by the over-modification effect of Gd.

KEYWORDS:

• Mg–Mg₂Si in situ composite
• Mg₂Si modification
• microstructural characterisation
• high-temperature strength

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.