Abstract
In this study, Inconel718 specimens with good mechanical properties were prepared by direct energy deposit (DED) with different laser processing parameters. The mechanical properties of Inconel718 samples fabricated by laser direct energy deposit method without heat treatment were measured. The fractures and metallographic structures of prepared Inconel718 were observed, and the mechanism of the effect of diverse machining parameters on mechanical properties of Inconel718 was analyzed from the micro level. The results showed the microstructures of depositions of Inconel 718 specimens prepared by DED were compact with fine grains and anisotropic microstructures, where macroscopic defects were barely seen. The mechanical properties and microstructures of Inconel718 were influenced by processing parameters, among which the forming angle and laser power had the most remarkable effect. According to the experimental data, it could be observed that the Inconel718 specimens prepared by DED had the best performance under the circumstance of 1400W laser power, 1.0mm layer thickness, 600mm/min scanning speed, 1.3mm hatch spacing, and 90° forming angle, whose ultimate tensile strength (UTS) and macro hardness were 1016.10MPa and 36.2HRC respectively. The UTS of Inconel 718 manufactured by DED was close to that of Inconel718 prepared by traditional forging, and even it had higher hardness.
Architectural tunability of mechanical metamaterials in the nanometer range
