Contribution in Optimization of Honeycomb Abradable Seals Structure

Abradable coating has significantly enhanced turbo-machinery performance by acting as a sacrificial seal between rotating blades and stationary casing. Further improvement in seal design to meet the higher energy demand and increase the service time have been the key challenges to solve in the gas turbine industry. Honeycomb seals have become the industry standard clearance seal technique due to its unique design and high structural strength with minimum weight. The present study proposes a concept to form a thermal shock resistance structure to achieve higher temperature capability and improve the reliability of abradable honeycomb seals. A cavity layer of honeycomb seal structure made of SS 321 alloy was coated with advanced high-temperature ZrO2 7.5Y2O3 4 polyester seal material using the TriplexPro-210 plasma spray system. The integrity of a seal structure was assessed by a cross-sectional analysis and evaluation of coating’ microstructure. Additionally, the micro-hardness test was performed to estimate coating fracture toughness, and Object-Oriented Finite Element analysis used to assess its thermo-mechanical performance. The concept proposed in this study should be further validated in order to develop the most capable innovative technology for advanced gas turbine seals.