Abstract

LOPEZ-NADAL, Rodolfo; JOSE-ZOQUI, Eugênio; SANCHEZ-ROCA, Ángel  and  CARVAJAL-FALS, Hipólito Domingo. Influence of temperature and time in the thixoformability of gray cast iron. Ingeniería Mecánica [online]. 2013, vol.16, n.3, pp.219-226. ISSN 1815-5944.

In this paper is study the influence of temperature and held times in the microstructure evolution, hardness and porosity of the thixoformed material. An alloy of hypoeutectic cast iron was design using the software Thermocal to obtain 40 and 50 % of solid phase in semisolid state. The alloy was produce by conventional casting in sand molds. The samples were heated to the semi-solid state at 1160 and 1180 ºC and held at these temperatures for 0, 30, 90 and 120s. The tests were carried out in eccentric press equipped whit two parallel platen. Tests reveal that the thixoforming operations change the graphite type from "A" to "B" (or "E"), but not affect the interdendritic arm spacing between graphite lamellae. The hardness of the thixoformed material showed an increase compared to designed alloy. The porosity analysis reveal a tendency to decrease whit the increase of temperature and holding time related with the original raw material.

Keywords : thixoforming; semisolid materials; ferrous alloys; morphology evolution; microstructure.

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