Producing thixotropic semi-solid A356 alloy: microstructure formation x forming behaviour

• Autorzy: Robert M. H. , Zoqui E. J. , Tanabe F. , Motegi T.
• Konferencja: 12th International Scientific Conference CAM3S'2006, 27-30th November 2006, Gliwice-Zakopane
• Języki publikacji: EN

Abstrakty

EN

Purpose: The work discuss the phenomena involved in the formation of the microstructure of semi-solid thixotropic alloy A356 produced by different techniques and the relation between microstructure and forming behaviour of the material. Design/methodology/approach: Thixotropic slurries of A356 alloy were produced from liquid and from solid conditions; in the first case either by stimulating nucleation rate or crystal multiplication during solid growth; in the second case by recrystallization and partial melting of deformed structures. Flow behaviour was analysed by viscosity measurements or by flow ability in forging operations. Findings: Results show that different production techniques activate different mechanisms, leading to distinct structure features in the semi-solid slurry, and, as consequence, in its forming characteristics. Techniques which promote formation of isolate globules of primary phase, like those involving nucleation stimulation and recrystallization, result in a semi-solid with better flowing behaviour. On the other hand, techniques based on crystal multiplication during growth lead to more interconnected globules in the slurry and poorer forming behaviour. Research limitations/implications: Semi-solid processing is suitable only for alloys with appropriate liquid fraction x temperature relation. Practical implications: the konowledge of the phenomena involved in the formation of thixotropic metallic slurries produced by different techniques, and their consequences in the material structure and flow behaviour, allow the decision of the adequate slurry production method for a specific application, in order to take the best advantage of the semi-solid technology. Originality/value: The analysis of the relation between production process x flow behaviour of semi-solid thixotropic A 356 is original.

Słowa kluczowe

EN

casting; semi-solid alloys; Al alloys; thixoforming

PL

odlewanie; stopy półstałe; stopy aluminium; kształtowanie w stanie częściowo ciekłym; otrzymywanie odlewów ze stopu w stanie stało-ciekłym

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2007
• Tom: Vol. 20, nr 1-2
• Strony: 19--26
• Opis fizyczny: Bibliogr. 15 poz., fot., rys.

Twórcy

autor

Robert M. H.

autor

Zoqui E. J.

autor

Tanabe F.

autor

Motegi T.

• Faculty of Mechanical Engineering, State University of Campinas, SP, CEP 13083-970, Brazil,

Bibliografia

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