Characterization of Thermally Sprayed Coated GT Components Made of 3D Printing Based Selective Laser Melting Processed Inconel Alloy 718

Mohammed Yunus,Mohammad S Alsoufi,Marco Pizzarelli

doi:10.1155/2021/2791386

Mohammed Yunus, Mohammad S Alsoufi + Show 1 more

Open Access

https://doi.org/10.1155/2021/2791386

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Abstract

Functional requirements like higher strength, resistance, and shielding from chemical reactions, degradation, etc., of the base metal are achieved by modifying their exposed surfaces using TBC (thermal barrier coating). Modified outer surface of components in the GT (gas turbine) improves the performance by the increase of inlet temperature, enhancing longer life and providing many interrelated surfaces to withstand severe working conditions. This work is based on characteristic (mechanical, thermal, and tribology) evaluation of TBC-coated GT components made of Inconel 718 manufactured from traditional and 3-D printing-based selective laser melting (SLM) process and compared. TBCs comprising bond coat and top ceramic oxide coat were deposited by High-Velocity Oxy-Fuel and Atmospheric Plasma Spraying techniques, respectively. Characteristics evaluated by varying coating thickness, standoff distance, substrate preheating, Input torch power, etc., revealed that characteristics of substrates manufactured from SLM methods improved significantly except porosity and average surface roughness. These improvements are essential for embedding sensors, thin films, etc., in TBCs for continuous monitoring of outputs.

Highlights

Gas turbines used in the propulsion of aircraft are characterised by highly structural integrity, low weight, and hightemperature resistant demand higher thermal efficiency, which is extensively dependent on the GT inlet temperature for extracting higher levels of energy from combustion [1]
The Ra value of both IN718 and selective laser melting (SLM) IN718 samples were measured taking an average of Ra at 5 different points of sprayed Bond Coat (BC) and TC surface by surface profilometer shows a great impact on the superior adhesive performance of TBCs [31] onto the substrate
The results of SLM IN718 specimens showed a high amount of average roughness in comparison with the traditional IN718 samples as produced by SLM IN718 samples exhibited very fine and porous structures

Summary

Introduction

Gas turbines used in the propulsion of aircraft are characterised by highly structural integrity, low weight, and hightemperature resistant demand higher thermal efficiency, which is extensively dependent on the GT (gas turbine) inlet temperature for extracting higher levels of energy from combustion [1]. To get enhanced thermal efficiency, several studies have been carried out on using newer materials, variation of operative temperature on the properties of high-temperature corrosion, microstructural changes, creep, etc. TBCs are popular with the well-known practices applied on components subjected to high-temperature performance in GT materials (made of IN718, Waspaloy, Hastelloy, etc.). TBCs were used with GT materials to handle problems of a higher range of temperatures such as oxidization, thermal cyclic loading, creep, and thermal corrosion. Otherwise, they would affect life and structural integrity [3]. TBCs provide various benefits stated above by increasing the durability of the components subjected to high temperatures and stresses.

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