The effect of adding Mn and Cr to the Al-Fe-Si system alloy

Abstract

Alloys of the Al-Fe-Si system have a complex phase composition that determines their properties. With a certain combination of temperature and composition, the conditions for the formation of the α phase are formed. However, with decreasing temperature, the α↔β transformation is observed. Suppression of the formation of the β phase is possible by doping. The main goal of this work was to substantiate theoretically the introduction of manganese and chromium into the alloy, and to explain the required number of alloying elements through a detailed analysis of the phase composition. The temperature limits for the formation of the α phase in the Al-Fe-Si ternary system and the kinetics of its recrystallisation were revealed. A justification for the value of the mass fraction of alloying elements that contribute to the suppression of the α↔β transformation with the formation of the cubic α phase was developed. The most successful suppression of the formation of the β phase occurs with joint alloying with manganese and chromium, with the formation of a predominantly cubic phase Al₁₅Si₂(Fe, Cr, Mn)₄ with a volume fraction of more than 95%, which predicts the possibility of plastic processing of iron and silicon-rich alloys of the Al-Fe-Si system.