Abrasive Coating on Gas Turbine Rotor Blade Tips
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Solution Overview
Problem
Existing methods for manufacturing abrasive coatings on gas turbine rotor blade tips often damage the base alloy, leading to oxidation and inefficiency due to high temperatures required for bonding, which compromises the structural integrity and clearance between blade tips and shrouds or casings.
Innovation Solution
A method involving blending high and low temperature melting alloy powders with abrasive particles, applying them to the rotor blade tip, and locally heating above the low melting point but below the high melting point to bond the abrasive particles without altering the base alloy properties, using induction heating in a vacuum or inert environment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If high temperature bonding is used to apply abrasive coating to rotor blade tips, then the abrasive particles are properly bonded to the blade tip, but the base alloy properties are altered and oxidation occurs
Solution Approach 1:
A nickel-based superalloy intermediate layer is applied between the abrasive particles and the rotor blade tip base alloy. This intermediate layer acts as a mediator that can withstand the high bonding temperatures without altering the base alloy properties, while still providing adequate bonding for the abrasive particles. The intermediate layer protects the base alloy from oxidation and property alteration during the bonding process.
Solution Approach 2:
The bonding temperature is controlled to be above the melting point of the low temperature melting alloy powder but below the melting point of the high temperature melting alloy powder and base alloy. This parameter change allows the abrasive particles to be properly bonded while preserving the base alloy properties. The temperature window is carefully selected to achieve bonding without damage.
2Strength
If uniform heating is used to bond abrasive coating, then the entire component reaches processing temperature, but properties of areas remote to the coated area are altered
Solution Approach 1:
Local heating is applied specifically to the rotor blade tip area where the abrasive coating is being applied, rather than heating the entire component uniformly. This local quality approach ensures that only the coated area reaches the high processing temperature needed for bonding, while remote areas remain at lower temperatures and maintain their original properties. The heating is spatially differentiated to match the coating application zone.
Solution Approach 2:
The heating process is segmented into different zones: the coated area experiences high temperature for bonding, while remote areas experience lower temperatures. This segmentation of thermal treatment allows the bonding process to occur locally without affecting the overall component properties. The thermal field is divided into active bonding zone and passive maintenance zone.
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 method achieves a high re-melt temperature abrasive coating that maintains the integrity of the base alloy, ensuring minimal clearance and improved gas turbine efficiency by preventing material loss and oxidation.
Implementation Method 1
locally heating said area of said gas turbine component to a temperature above the melting point of said low temperature melting alloy powder but below the melting point of said high temperature melting alloy powder
Implementation Method 2
using induction heating in a vacuum or inert environment
Data Source
AI summary
A method for manufacturing an abrasive coating on a gas turbine component, especially on a gas turbine rotor blade tip, comprising at least the following steps: a) providing a gas turbine component, especially a gas turbine rotor blade; b) providing a high temperature melting alloy powder; c) providing abrasive particles; d) providing a low temperature melting alloy powder; e) blending at least said high temperature melting alloy powder and said abrasive particles to provide a mixture; f) applying said low temperature melting alloy powder and said mixture to an area of said gas turbine component, especially to a tip of said turbine rotor blade; g) locally heating said area of said gas turbine component to a temperature above the melting point of said low temperature melting alloy powder but below the melting point of said high temperature melting alloy powder is provided.