Abradable Seal Wear Distribution via Hard Tip and Soft Matrix
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wear-resistant seal systems in gas turbine engines fail to effectively manage wear between rotating blades and abradable material housings, leading to airflow leakage and reduced operational life due to improper material selection, where the abrasive tip causes damage to the matrix material instead of the filler material, resulting in inefficient sealing.
Innovation Solution
The use of a harder abrasive tip made from materials like austenitic nickel-chromium-based alloys and a softer matrix material with lower tensile strength, such as Cu5Al, Cu8Al1Fe, or Cu38Ni, to ensure that the abradable material is worn more than the tip, reducing damage and maintaining an effective seal across varying temperatures and pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If a wear-resistant seal system uses a harder abrasive tip material, then the tip durability is improved, but the matrix material damage increases when improper material selection is used
Solution Approach 1:
The patent applies parameter changes by carefully selecting and adjusting the hardness and tensile strength parameters of both the abrasive tip material and matrix material. The abrasive tip is made harder (e.g., austenitic nickel-chromium-based alloys) while the matrix material is made softer with lower tensile strength (e.g., Cu5Al, Cu8Al1Fe, or Cu38Ni), creating an optimized wear distribution where at least 90% of volume loss occurs from the abradable material rather than the tip.
Solution Approach 2:
The patent employs composite materials by combining a harder abrasive tip material with a softer matrix material in a wear-resistant seal system. This composite structure allows the harder tip to resist wear and maintain durability while the softer matrix material absorbs damage and protects the underlying structure, achieving both tip durability and reduced matrix damage simultaneously.
2Reliability
If the abrasive tip is made harder to resist wear, then the sealing efficiency is improved, but the operational life is reduced due to thermal cycle-induced failures
Solution Approach 1:
The patent resolves this contradiction by changing the material parameters to create a harder abrasive tip that maintains sealing efficiency while the softer matrix material with lower tensile strength absorbs thermal stresses during cycling. This parameter optimization ensures that wear distribution favors the abradable material (at least 90% volume loss), protecting the tip and extending operational life under thermal cycles.
Solution Approach 2:
The patent applies this principle by designing the matrix material to be sacrificial - it is intentionally made softer and more susceptible to wear and thermal damage. The matrix material acts as a protective layer that degrades preferentially, shielding the more critical abrasive tip and underlying structure from thermal cycle-induced failures, thereby extending the overall system operational life.
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
This configuration achieves a wear distribution where at least 90% of the volume loss occurs from the abradable material, minimizing damage to the abrasive tip and rotating blade, while maintaining structural integrity and reducing thermal cycle-induced failures, thus enhancing the operational life and sealing efficiency of the gas turbine engine.
Implementation Method 1
the tips of the rotating blades abrade the abradable material
Implementation Method 2
During the first run of the gas turbine engine (i.e., the 'green run,') the tips of the rotating blades abrade the abradable material
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
What is described is a wear resistant seal system that is adapted for resisting wear of a rotating part in a gas turbine engine (20) as it rotates against a stationary part in the engine (20). The system includes an axially rotable member including an abrasive tip (208) having a first tensile strength. The system also includes a stationary structure radially exterior and adjacent to the rotable member and including an abradable material (206). The abradable material (206) includes a matrix material (300) having a second tensile strength that, at least in a first temperature range, is lower than the first tensile strength and a filler material (302) interspersed with the matrix material (300).