The creep behavior of Mg–9Al–1Si–1SiC composite at elevated temperature

Abstract

The creep properties of as-cast Mg–9Al–1Si alloy and Mg–9Al–1Si–1SiC composite were compared. The results show that Mg–9Al–1Si–1SiC composite performs a better creep resistance than that of Mg–9Al–1Si alloy at constant temperature and stress (473 K,70 MPa). Besides, the creep behavior of Mg–9Al–1Si–1SiC composite at various temperature from 448 K to 498 K and under stresses of 70–90 MPa were systematically investigated. The Mg–9Al–1Si–1SiC composite exhibited a stress exponent from 5.5 to 6.9 and the creep activation energy fell within the range of 86–111 kJ/mol. The results showed that the creep mechanism of Mg–9Al–1Si–1SiC composite was mainly attributed to the effects of secondary phase strengthening mechanism and dislocation climb mechanism.

Keywords

• Microstructure
• Stress exponent n
• Creep activation energy Q
• Mg–9Al–1Si–1SiC composite