Production of AA2124/MoSi2/25p composites and effect of heat treatment on their microstructure, hardness and compression properties
| Autor: | Marcela Lieblich, Fatemeh Piyadeh, Hassan Abdollah-Pour |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Revista de Metalurgia. 50:e030 |
| ISSN: | 1988-4222 0034-8570 |
| DOI: | 10.3989/revmetalm.030 |
| Popis: | AA2124/25vol%MoSi2 composites were processed by two powder metallurgy routes: high energy ball milling of the reinforcement and alloy powder (B composite) and wet blending with cyclohexane (W composite), both followed by extrusion to achieve full consolidation. As-extruded and heat treated composite bars were studied microstructurally and mechanically (hardness and compression tests under quasistatic loading). Microstructure and fracture profiles were observed by scanning electron microscopy and the reaction products formed in the matrix were identified by energy-dispersive X-ray spectroscopy and X-ray diffraction analysis. The results show that for both composites, the hardness of the specimens in solution and aged condition was higher than in the as-extruded condition. The hardness of the B composite was higher than that of the W composite whereas the age-hardenability of the B composite was significantly lower than that of the W composite. After heat treatments, small diffusion reaction phases appeared at the interface between matrix and reinforcements. Compressive yield strength and the ultimate strength of both composites improved considerably after the artificial ageing. The composite fracture surfaces exhibited microscopically a ductile appearance that consisted of dimples in the matrix and a fragile fracture of the MoSi2 particulates. |
| Databáze: | OpenAIRE |
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