The Effect of Aluminum on Microstructure and Mechanical Properties of ATI 718Plus Alloy

Abstract

In this reported study, the influence of aluminum concentration on the microstructure and mechanical properties of alloy ATI 718Plus was investigated. The experimental results revealed that the content of aluminum has a significant effect on the solvus temperature and the chemical compositions of the γ′ and δ phases of ATI 718Plus. The experimental data showed that an increased concentration of aluminum in the alloy caused the tensile strength to increase, but had a negative impact on the metal’s ductility. The distribution of aluminum in the matrix and phases of the alloy were systematically examined using the atom probe tomography (APT) technique. The precipitation of phases in the alloy resulting from heat treatment was predicted using the JMatPro 6.0 software application and the predicted results were verified experimentally using electrolytic phase separation followed by microchemical analysis. In addition, a more detailed analysis of the size distribution of the γ′ and crystal structure of the δ phase in the alloy was performed using SEM and XRD analysis. A full discussion of the effects of aluminum content on the mechanism of the generation of the alloy microstructure and evolution of the tensile properties is included in this report.