Abrasive Turbine Blade Tip Alloy for Durable Shroud Rubbing
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Solution Overview
Problem
Existing methods for forming abrasive materials on turbine blade tips are not durable for long-term engine use due to limitations in blade tip design resulting from fabrication techniques, leading to significant wear and reduced compressor or turbine performance.
Innovation Solution
A method involving the mixing of metal powder with carbon powder to form a carbon-enriched metal powder, which includes refractory elements like tungsten, tantalum, or titanium, and bonding this mixture to the turbine blade tip using laser deposition or electron-beam welding, causing the carbon to combine with these elements and form hard carbide particles that act as abrasives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If abrasive particles are embedded in the blade tip using entrapment plating method, then the blade tip gains abrasive properties to reduce wear, but the fabrication technique limits the blade tip design and reduces durability
Solution Approach 1:
The invention changes the fabrication parameters from entrapment plating to laser deposition or electron beam welding, which allows for greater design flexibility and improved durability. The laser deposition process enables precise control over the abrasive particle distribution and blade tip geometry, resolving the contradiction between fabrication limitations and design freedom.
Solution Approach 2:
The invention replaces the mechanical entrapment plating process with energy-based laser deposition or electron beam welding. This substitution eliminates the design constraints inherent in mechanical plating methods while maintaining the abrasive properties of the blade tip, thereby improving both durability and design flexibility.
2Productivity
If blade tip dimensions are tightly controlled to minimize clearance, then compressor and turbine efficiency is improved, but the blade tip becomes more susceptible to wear during rubbing
Solution Approach 1:
The invention creates a composite blade tip structure by depositing abrasive-containing material onto the base blade tip alloy. This composite structure provides both the tight dimensional control needed for efficiency and the enhanced wear resistance required during rubbing, as the abrasive particles (such as cubic boron nitride or silicon carbide) are embedded within a nickel-based superalloy matrix.
Solution Approach 2:
The invention applies abrasive material specifically to the blade tip region where wear occurs, rather than treating the entire blade. This localized approach maintains the tight dimensional tolerances needed for efficiency while providing enhanced wear resistance only where needed, resolving the contradiction between efficiency and wear resistance.
3Reliability
If clearances between blade tips and shroud are increased to accommodate wear, then blade tip durability is improved, but compressor and turbine performance decreases
Solution Approach 1:
The composite blade tip structure with embedded abrasive particles provides enhanced durability, allowing the blade to withstand rubbing without significant wear. This enables the maintenance of tight clearances for optimal performance while ensuring the blade tip can tolerate interference rubs without degradation, thus resolving the contradiction between durability and performance.
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 method enhances the durability of turbine blade tips by forming abrasive carbide particles that reduce wear during rubbing against the shroud, thereby improving compressor and turbine efficiency by minimizing high-pressure air leakage.
Implementation Method 1
The step of bonding includes raising the temperature of the carbon-enriched metal powder past its melting point
Implementation Method 2
Bonding the carbon-enriched metal powder is performed using a laser deposition process or an electron-beam welding process
Implementation Method 3
raising the temperature of the carbon-enriched metal powder past its melting point
Implementation Method 4
Bonding the carbon-enriched metal powder to the turbine blade tip
Data Source
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AI summary
A method of forming an abrasive nickel-based alloy on a turbine blade tip includes producing or obtaining a metal powder that is mixed with a carbon powder to form a carbon-enriched metal powder. The metal powder includes a refractory element. The method further includes bonding the carbon-enriched metal powder to the turbine blade tip. The step of bonding includes raising the temperature of the carbon-enriched metal powder past its melting point, thereby causing the carbon to combine with the refractory elements to form abrasive carbide particles.