THE EFFECTS OF MN ADDITION FOR THE PREDICTION OF THE THIXOFORMABILITY OF FE-CONTAINING AL-SI BASED ALLOYS

M. V. Koshelev, E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

A. G. Prigunova, E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it., ORCID: https://orcid.org/0000-0001-8030-9160

A. G. Vernidub

Physico-Technological Institute of Metals and Alloys of the NASU, Kyiv

Abstract

The effects of Mn addition for the prediction of the thixoformability of Fe-containing Al-Si based alloys have been investigated by DTA and optical microscopy. The experimental findings clearly demonstrated that altered Mn/Fe ratios (up to 0.7) in the studied alloys can reduce temperature sensitivity of liquid fraction (df_L/dT_0.3–0.5) and enlarge to a large extent the solidification temperature interval and the temperature window between 30% and 50% fraction liquid. Moreover, with increasing Mn/Fe ratio from 0.3 to 0.7 plate-like β-Al₅FeSi phase transforms to a more compact α* - Al(FeMn)Si phase which are more favorable for the semi-solid forming technology.

Keywords: thixoformability, Al-Si based alloys, phase transformation