ABSTRACT
This study compares the microstructures and hardness of an AlSi10.6CuMg alloy obtained by sand casting and high pressure die casting (HPDC). The results show that the morphology of HPDC dendrites was not uniformly distributed as in sand casting. HPDC refines the morphology of intermetallics and produces a modification of eutectic silicon. Chinese-script is the dominant iron intermetallic in sand casting, while primary polyhedral and secondary proeutectic particles are dominant in HPDC. The results of the X-ray diffraction show the presence of high residual stresses in the HPDC. Deep etching for HPDC samples reveals θ-Al2Cu phases in very thin compact dendrites. No evidence of twin plane re-entrant edge assistance was found in the growth of primary silicon. The primary silicon plate-like becomes unstable in HPDC, resulting in smooth and rounded outer surfaces. Hardness of HPDC alloy was about 11% higher than that of sand casting alloy.
Acknowledgements
Said Beroual is grateful to the members of the research team ID2M of the IMN laboratory, located in Nantes-France, especially Prof. Pascal Paillard for assistance with the use of the Vickers tester, performing X-ray diffraction, optical microscopy and SEM analyses. The authors would like to thank Mr. Yazid Mahroug of ETRAG located in Constantine-Algeria for furnishing the aluminum specimens.
Disclosure statement
No potential conflict of interest was reported by the authors.
Correction Statement
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