Estudo do efeito do tamanho de grão no comportamento mecânico do latão 60-40

Abstract

Copper alloys, such as 60/40 brass, have excellent hot workability, good mechanical properties and excellent recyclability. For these reasons they are applied in the manufacture of plates, bars and profiles, in addition to use in applications in condenser tube plates and heat exchangers. These materials depend on the size of the grain, and their difference can change their properties and must therefore be controlled according to the final application. This grain size is directly proportional to the flow limit of the material, thus producing a dependency that can be explained through the empirical Hall-Petch equation. A reduction in grain size offers the material greater resistance, but less ductility. As a way of controlling this grain size, the annealing heat treatment is carried out. For these reasons, this work aims to study the different grain sizes obtained through the annealing heat treatment at 480° C for different times. From that point on, the analysis through tensile and hardness tests of how this heat treatment at different times generated different grain sizes and thus influenced the mechanical properties of and, using the Hall-Petch equation, to understand the dependence of the limit flow with grain size.