Arc-based directed energy deposited Inconel 718: role of heat treatments on high-temperature tensile behavior

Abstract

This study evaluated the effect of dedicated heat treatments (1050C, 1100C, 1142C, and 1185C/2 h + double-aging) on the uniaxial tensile properties at elevated temperature (650C) of Inconel R 718 fabricated via arc plasma directed energy deposition. They enabled to meet, for the first time, the AMS 5662 requirements at elevated temperature. Tensile tests exhibited ductile strain-stress curves. The 1100C/2 h + double-aging showed the best performance (YS 0.2% , UTS, and elongation of 967 MPa, 1126 MPa, and 18.7%, respectively). Additionally, vertical specimens evidenced dynamic strain aging, although no brittle-like features were observed.