Creep behavior of AE42 based hybrid composites

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 460; pp. 268 - 276
• Main Authors: Arunachaleswaran, A., Pereira, I.M., Dieringa, H., Huang, Y., Hort, N., Dhindaw, B.K., Kainer, K.U.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-07-2007; Elsevier
• Subjects: AE42; Applied sciences; Compression; Creep; Elasticity. Plasticity; Exact sciences and technology; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; MMC; Saffil; SiCp; Saffil; MMC; Compression; SiCp; Creep; AE42; Short fiber; Heat treatment; Creep test; Creep strength; High temperature; Precipitate; Composite material; Dislocation climb; Effective stress; Interface reaction; Activation energy; Squeeze casting; Aluminium oxide; Magnesium oxide; Mechanical properties; Compression test; Magnesium base alloys; Silicon carbide; Experimental design
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2007.01.043

Magnesium alloy based hybrid composites with varying levels of δ-alumina short fibers (Saffil
f
®) and SiC particles (SiC
p) reinforcements have been prepared by the squeeze casting technique. The results of the studies done on the basis of microstructural changes and compression creep tests show that the composites with 10
vol% Saffil
f
®
+
15
vol% SiC
p exhibits relatively better creep resistance compared to its other counterparts with 10
vol% Saffil
f
®
+
10
vol% SiC
p and 15
vol% Saffil
f
®
+
5
vol% SiC
P. The effect of solutionising heat treatment on these composites does not yield any remarkable improvement in its creep properties. Investigations on these composites reveal the presence of Mg
2Si and Al–RE precipitates. The presence of these precipitates was found to enhance the creep resistance of AE42 hybrid composites. The composites were found to exhibit threshold creep behavior as expected. The effective stress exponents and the activation energy values calculated suggest that ‘glide and high temperature climb of dislocations’ as the predominant creep mechanism. The interfacial reaction products were MgO and Mg
2Si. The interfacial reaction product MgO is more pronounced along the Saffil
f
® compared to SiC
p. A similar behavior was observed in composites before and after heat treatment.