Dense Abradable Coating for Turbine Engine Parts
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Solution Overview
Problem
Conventional abradable coatings in gas turbine engines are highly porous, making them prone to oxidation and having limited life expectancy at high temperatures, which fails to withstand the extreme conditions of advanced industrial gas turbines.
Innovation Solution
A dense abradable coating comprising a pore-free metallic composite, a high-aluminum containing brittle alloy, and hollow abradable particles is applied to reduce porosity and enhance oxidation resistance, maintaining abradability and stability at temperatures above 900 °C (1650°F).
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If conventional highly porous abradable coatings are used, then abradability is achieved, but oxidation resistance and high temperature stability deteriorate
Solution Approach 1:
The patent applies composite materials by combining three distinct components: a pore-free metallic composite (providing structural integrity and oxidation resistance), a high-aluminum brittle alloy (providing oxidation resistance through aluminum oxide formation), and hollow abradable particles (providing abradability). This composite structure resolves the contradiction by integrating materials with complementary properties, where the pore-free metallic composite matrix prevents oxidation penetration while the hollow particles maintain abradability, achieving both oxidation resistance and reliable performance at high temperatures.
2Reliability
If conventional highly porous abradable coatings are used, then abradability is achieved, but porosity increases leading to oxidation and reduced life expectancy
Solution Approach 1:
The patent applies local quality by creating a coating with spatially differentiated properties: the pore-free metallic composite matrix provides a dense, oxidation-resistant continuous phase, while hollow abradable particles are distributed within this matrix to provide localized abradability. This local differentiation allows the coating to exhibit both low overall porosity (for oxidation resistance) and sufficient abradable content (for blade clearance accommodation), resolving the contradiction between reducing porosity and maintaining reliability.
3Object-generated harmful factors
If dense pore-free coating is used, then oxidation resistance improves, but abradability may deteriorate
Solution Approach 1:
The patent resolves the contradiction between oxidation resistance and abradability through composite materials by embedding hollow abradable particles within the pore-free metallic composite matrix. The dense matrix provides oxidation resistance, while the hollow particles (comprising 5-50 wt% of the coating) provide controlled abradability. The hollow structure of these particles allows them to fracture and wear away progressively, maintaining abradability despite the dense matrix structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The coating significantly reduces rub damage and extends the life expectancy of turbine engine parts by maintaining structural integrity and preventing progressive oxidation-based loss at high temperatures, with reduced airflow leakage and improved engine performance.
Implementation Method 1
abradable particles component for providing abradability
Implementation Method 2
a high aluminum containing brittle alloy component for assisting with oxidation resistance
Data Source
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AI summary
Various embodiments include a dense abradable coating, a method of reducing rub damage to a turbine engine part by applying the dense abradable coating thereto, and a turbine engine part having the abradable coating thereon. Particular embodiments include a dense abradable coating including a pore-free metallic composite, a high-aluminum containing brittle alloy, and a plurality of hollow abradable particles.