Effect of Yttria-stabilized zirconia coating on the corrosion and thermal behaviour of additive manufactured Inconel 718 alloy

Abstract

The need for additively manufactured Inconel 718 alloy is increasing in high-temperature functional applications, including gas turbine engines, aviation engines, cast blades, and housings. The proposed work aims to improve the corrosion resistance and thermal characterization of additively manufactured Inconel 718 using a Yttria Stabilized Zirconia (YSZ) thermal barrier coating. YSZ is coated on the additively manufactured Inconel 718 alloy using a plasma spraying process. Using an electrochemical workstation, a corrosion test is conducted for the YSZ-coated Inconel 718 alloy and the non-coated Inconel 718 alloy. Thermal shock loading and thermal stability analysis for the YSZ-coated Inconel 718 alloy are carried out using a tubular furnace and a thermogravimetric analyser. YSZ-coated, additively manufactured Inconel 718 alloy is characterized by phases formed, microanalysis of corroded specimens, morphology, surface cracks, and elemental presence using X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Energy dispersive spectroscopy (EDS). YSZ-coated Inconel 718 alloy shows a minimum corrosion rate of 0.0000472 mm/year, which is better than the non-coated Inconel 718 alloy (5.93 mm/year). The YSZ coating on Inconel 718 alloy improved the thermal stability and thermal shock resistance better than the non-coated Inconel 718 alloy.