On the peritectoid Ti{sub 3}Si formation in Ti-Si alloys

Journal Article · Wed Mar 15 04:00:00 EST 2006 · Materials Characterization

DOI:https://doi.org/10.1016/j.matchar.2005.09.009· OSTI ID:20833189

Ramos, Alfeu Saraiva ^[1]; Nunes, Carlos Angelo ^[2]; Coelho, Gilberto Carvalho ^[2]

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1. Universidade do Vale do Paraiba, Instituto de Pesquisa e Desenvolvimento, Sao Jose dos Campos-SP, CEP 12244-000 (Brazil)
2. Faculdade de Engenharia Quimica de Lorena, Departamento de Engenharia de Materiais, Lorena - SP, CEP 12600-000 (Brazil)

Ti-13.5Si and Ti-25Si (at.%) alloys have been arc-melted from high-purity raw materials, using a water-cooled copper hearth, a non-consumable tungsten electrode, and under an Ar atmosphere gettered by titanium. The cast ingots were then heat-treated for 90 h at 1000 and 1100 deg. C in an inert atmosphere, and both the as-cast and the heat-treated alloys were characterized using scanning electron microscopy and an energy dispersive microanalysis system. The as-cast Ti-13.5Si alloy presented a eutectic microstructure composed of the Ti{sub SS} and Ti{sub 5}Si{sub 3} phases, while the microstructure of the as-cast Ti-25Si alloy showed the presence of large primary precipitates of Ti{sub 5}Si{sub 3} in a eutectic matrix of Ti{sub SS} and Ti{sub 5}Si{sub 3}. Subsequent heat treatment at 1100 deg. C produced no significant microstructural modifications in the Ti-25Si alloy, and it is suggested that the presence of the large primary precipitates of Ti{sub 5}Si{sub 3} contributed to a reduction in the kinetics of Ti{sub 3}Si formation. In the Ti-13.5Si alloys, the formation of Ti{sub 3}Si was not observed after heat treatment at 1000 deg. C, but a large amount of Ti{sub 3}Si was found after heat treatment at 1100 deg. C, confirming its existence in Ti-Si alloys containing low interstitial contents.

• OSTI ID: 20833189
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Journal Issue: 2 Vol. 56; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AFTER-HEAT
EUTECTICS
HEAT TREATMENTS
KINETICS
MICROANALYSIS
PHASE DIAGRAMS
SCANNING ELECTRON MICROSCOPY
SILICON ALLOYS
TITANIUM ALLOYS
TITANIUM SILICIDES