한국주조공학회

The effects of Ti, B and Zr on grain refinement and castability were investigated in Al- 4wt%Mg-0.9wt%Si-0.3wt%Mn-0.15wt%Fe alloy. Measurement of cooling curve and micro-structure observation were performed to analyze the effects of the addition of minor elements Ti, B and Zr during solidification. The prominence of effect on grain refinement was in increasing order for Ti, Zr and B element. Fine grain size and an increase of the crystallization temperature for α-Al solution were evident as the amount of addition elements increased in this study. Addition of 0.15wt% Ti was most effective for grain refinement, and the resulting grain size of α-Al solution for shell mold and steel mold were 72.3 μm and 23.5 μm, respectively. Fluidity and shrinkage tests were perform to evaluate the castability of the alloy. Maximum fluidity length and minimum ratio of micro shrinkage were recorded for 0.15wt% Ti addition due to the effect of the finest grain size.

Grain refinement, Fluidity test, Shrinkage test, Al-4wt%Mg-0.9wt%Si-0.3wt%Mn-0.15wt%Fe alloy