Interface Characteristics and Mechanical Properties of Post-treated Directed Energy Deposition Laminated Composites

Laminated composites of IN718-95% IN718 + 5% (Cr2O3 + 25% TiO2) were fabricated by directed energy deposition, which were subjected to different posttreatment methods. The interfacial microstructures and mechanical properties of the laminated composites were studied by room temperature tensile tests and impact tests and analyzed by SEM and XRD. The interfacial morphology of the laminated composites after different treatment methods was compared. The effects of different treatment temperatures on the microstructure morphology and precipitate composition were analyzed. The results show that the precipitated strengthening phases improve the microhardness of solution by double aging (SA) treatment and homogenization, solution and double aging (HSA) treatment. The impact toughness and tensile strength are closely related to the heat treatment temperature and time. The impact toughness of the laminated composites reached 53.13 J/cm2, and the ultimate tensile strength reached 1339.85 MPa after HSA treatment.