Agradecimentos: The authors are grateful for the financial support received from CAPES (The Federal Agency for the Support and Assessment of Postgraduate Education, Brazil), CNPq (The National Council for Scientific and Technological Development, Brazil, Project Universal No. 470572/2011-6), and...

Agradecimentos: The authors are grateful for the financial support received from CAPES (The Federal Agency for the Support and Assessment of Postgraduate Education, Brazil), CNPq (The National Council for Scientific and Technological Development, Brazil, Project Universal No. 470572/2011-6), and FAPESP (São Paulo State Research Foundation), the last of which also provided technical support (Project FAPESP 2013/09961-3)

Thixoforming depends upon three aspects: (a) solid to liquid transformation; (b) size and morphology of the remaining solid phase in the semisolid state, and (c) the effect of both input factors on rheology of the semisolid slurry. The aluminum A356 alloy presents an ideal solid to liquid...

Thixoforming depends upon three aspects: (a) solid to liquid transformation; (b) size and morphology of the remaining solid phase in the semisolid state, and (c) the effect of both input factors on rheology of the semisolid slurry. The aluminum A356 alloy presents an ideal solid to liquid transformation, but the solidification process generates coarse aluminum dendrites surrounded by eutectic. In this regard, Equal Channel Angular Pressing (ECAP) has great potential as a method for manufacturing thixotropic raw material due to its grain refining effect. Therefore, the microstructure evolution and rheological behavior in the semisolid state of an ECAPed aluminum A356 alloy were investigated. Samples were heated up to 853 K (580 °C) and held for 0, 30, 60, 90, 210, and 600 seconds at this temperature. The isothermal heat treatment caused the globularization of the solid phase without any significant microstructure coarsening. Compression tests were carried out at the same temperature and holding times using an instrumented mechanical press. Apparent viscosities values close to 250 Pa s were obtained, revealing the exceptional rheological behavior of the produced samples. The thixoformed material also presented good mechanical properties, with high yield and ultimate tensile strength values (YS = 110/122 MPa, UTS = 173/202), and good ductility (E = 6.9/7.5 pct). These results indicate that the production of the A356 alloy via the ECAP process increases its thixoformability

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP

2013/09961-3

COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ

470572/2011-6

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