Effect of Heating Rate on Microstructure and Mechanical Properties in Al 7055

Abstract: The effects of the heating rate during solid solution heat treatment on the mechanical properties and microstructure of the 7055 aluminum alloy were investigated. The dissolution and formation kinetics of the precipitates in the sample before the solid solution treatment vary depending on the heating rate. This is because the dissolution and formation of precipitate particles are diffusion-controlled. Therefore, dilatometric tests were carried out to control the heating rates during the solid solution treatment. Then, the mechanical properties were evaluated using hardness and compressive tests, while the microstructural features were observed using X-ray diffraction, optical microscopy, and scanning transmission electron microscopy. The characteristics of the precipitate for each heating rate were calculated using thermodynamic simulation, and a model to predict the mechanical properties was proposed based on the results. Graphic Abstract: [Figure not available: see fulltext.]