Análise de resistência ao impacto da liga AI-Mg-Zn solidificada através do método de solidificação Squeeze Casting

Abstract

The foundry is often considered one of the oldest, if not the most versatile process for manufacturing metal components, inside foundry the squeeze casting is an innovative process. This applied to aluminum and magnesium alloys considerably modifies the structure of the metal when compared to other methods. The process consists in pouring the metal in a metallic permanent mold and solidification occurs under pressure caused by pressing a punch, which pressure varies reaction eutectic solidification of the metal. A disadvantage of conventional foundry processes is the formation of bubbles, pores, defects Schinkage and macrosegregation which directly influence on the mechanical properties of the cast products. In this study we analyzed the structural and mechanical impact of the alloy Al-Mg-Zn solidified under pressure and with use of variation in the composition of Zn 0%, 1%, 2% and 3% in the Al-alloy 7% Mg. Selected through the history of good results in the literature solidification by squeeze casting. It was observed that the pressure exerted influence on decreasing the macrostructure presence of casting defects in the final microstructure, the increased pressure reduced the secondary dendritic spacing, being observed thus increased cooling rate. This process contributed to the selection of an alloy of Al-Zn-Mg casting defects with minimal results and better impact resistance for the composition analyzed.