Influence Of The Portevin-Le Chatelier Phenomenon On The Ultimate Tensile Strengh Limit Of Alloys Al-0.18%Zr-2%Mg And Al-0.18%Zr-6%Mg 2019-36-0301

The effect of Portevin-Le Châtelier (PLC) effect and its influence on the mechanical properties of aluminum, have aroused interest in the scientific community, aiming possible applications in the industry. The respective effect has been commonly observed in the solid solution state in Al-Mg alloys. Therefore, the objective of this work is to analyze the effect of the PLC phenomenon on the mechanical properties of the material with additions of 2% and 6% of Mg in the base alloy of Al-0.18%. For this purpose, the alloys were cast in a muffle furnace and cast in copper mold (section of the properzi wheel), followed by cooling in water. Samples were cut and machined to 9.5 mm in diameter. Subsequently, they underwent sanding and polishing processes in order to obtain their macrostructures. The results obtained in this step show that Mg refined the grain structures. The tensile test was performed for mechanical characterization. The results showed that increasing Mg contents resulted in grain refining, tensile strength limit and elongation losses. In order to analyze the effect of PLC in the stress strain curves, a practical method was developed, which consists in amplifying the points of the curves, measuring the amplitude of the oscillations by zone and individual, from which it was concluded that the oscillations were more evident in the alloy with addition of 2% Mg.