Microstructural characterization of rapidly solidified AlSi alloys

1988; Elsevier BV; Volume: 98; Linguagem: Inglês

10.1016/0025-5416(88)90144-9

ISSN

1873-4928

Autores

N. Apaydin, Richard W. Smith,

Tópico(s)

Solidification and crystal growth phenomena

Resumo

AlSi alloys of composition varying from 9% Si to 30% Si have been rapidly solidified by melt spinning. Alloys up to 25% Si showed either fine or coarse microstructure depending on the thickness of the ribbon. Primary silicon phase was not observed in either case. The structure consisted of primary α-Al phase, outlined by a very fine duplex structure in thin ribbons, whereas discrete silicon crystals decorated the α-Al phase in thich ribbons. At 30% Si composition primary silicon phase formed abundantly in the form of idiomorphic crystals. In this alloy, eutectic grains, exhibiting an almost regular morphology, were also observed. The decomposition process of the alloys was followed using differential scanning calorimetry and a correlation was observed between the thermal response and the microstructure of the samples as a function of their thickness and composition.

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