Efficiency increase by surface modification of gas turbine blade
1 Methodist College of Engineering & Technology, Abids Hyderabad Telangana State-1_India
2 Methodist College of Engineering & Technology, Abids Hyderabad Telangana State-1_India
Research Article
Global Journal of Engineering and Technology Advances, 2020, 02(03), 022-034.
Article DOI: 10.30574/gjeta.2020.2.3.0010
Publication history:
Received on 17 February 2020; revised on 10 March 2020; accepted on 12 March 2020
Abstract:
Thermal barrier coatings (TBC’s) are used to provide both thermal insulation and oxidation protection to high temperature components within gas turbines. The development of turbines for power generation and aviation has led to designs where the operation conditions exceed the upper limits of most conventional engineering materials. As a result, there has been a drive to improve thermal barrier coatings to allow the turbine to operate at higher temperatures for longer. The focus of this project is on thermal barrier coatings with lower conductivity and longer lifetime than those coatings used in industry today. The route taken to achieve these goals with APS TBC’s has been twofold.
Firstly, an alternative stabilizer has been chosen for the zirconium oxide system in the form of yttria (Yttrium oxide, also known as yttria, is Y2O3. It is an air-stable, white solid substance. Yttrium oxide is used as a common starting material for both materials science as well as inorganic compounds). Secondly, variations in thickness of coating. The focus of the work has therefore been to characterize their lifetime and thermal properties when produced in a complete TBC system.
In earlier work yttria stabilized zirconia was used only for a particular thickness value. In this work different values of thickness are used for topcoat and characterization of this coated material is determined. While small at room temperature and in the as produced state; the influence becomes more pronounced at high temperatures and with longer thermal exposure time. The thermal barrier coated specimen of varying thickness was tested at both steady and transient conditions. There were many parameters being evaluated like hardness, surface roughness, microstructure and temperature gradient and stress distributions in the specimen. The temperature gradient was determined both under steady state and transient conditions experimentally as well as computationally using ANSYS V17.
Keywords:
Thermal barrier coating; Yttrium oxide; Hardness; Surface roughness; Microstructure; Temperature gradient and Stress distribution.
Full text article in PDF:
Copyright information:
Copyright © 2020 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0