Tratamento de envelhecimento artificial das ligas 356 e a 356: efeitos da composição química, do tempo e da temperatura nas propriedades mecânicas / Artificial aging heat treatment of 356 and A356 aluminum alloy: effect of chemical composition, time and temperature on the mechanical properties




This study evaluates the effect of chemical composition and heat treatment of aging on the mechanical properties of aluminum alloy 356. The variables of heat treatment were the magnesium content, time and temperature. Additionally, the effect of alloying elements present as Fe and Mn were also evaluated by comparing with the A356 which is the purest version of the 356.0 alloy. For alloy 356, two amount of magnesium were used, 0.3% and 0.5% in weight and the alloy was called the 356 low Mg and 356 high Mg, respectively.The samples were treated at constant temperature and varying times and after analysis of mechanical strength more specimens were cast that were treated at constant temperature, varying the time. In addition to tensile tests, other techniques were used to evaluate the material.Microhardness tests, optical microscopy and scanning electron microscopy analysis with point EDX were used.Comparing alloys with low and high magnesium content were observed significant variations in the mechanical properties .Besides this variable, the time and temperature of heat treatment also caused changes in the mechanical properties.At high temperatures can be observed the possible effect of over aging, where a decrease in mechanical strength was obsserved.In the microstructural analysis of the alloy 356 was noticed the presence of intermetallic iron-rich and the same was not found when we evaluated the microstructure of the alloy A356.As mechanical properties of A356 alloy showed values slightly lower than those obtained for the mechanical properties of alloys 356.This fact may be related to the presence of hardening elements such as copper and other alloying elements such as iron and manganese present in the alloy 356.


engenharia de materiais e metalurgica magnésio tratamento térmico de ligas de alumínio envelhecimento mechanical properties aging propriedades mecânicas heat treatment metais aluminum alloys alloying elements

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