Composite Coating with Sacrificial Particles for Turbine Erosion and Corrosion
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Solution Overview
Problem
Metal components in turbines face simultaneous challenges of corrosion and erosion due to extreme operating conditions, with existing coatings lacking effectiveness in addressing both issues simultaneously.
Innovation Solution
A coating comprising a metallic binder, hard particles, and sacrificial particles is applied to the metal components, providing erosion and corrosion resistance through anodic protection and self-healing properties, with the metallic binder including cobalt, nickel, or shape memory alloys, and hard particles like tungsten carbide, and sacrificial particles like hexavalent chromium.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate coatings are applied for corrosion resistance and erosion resistance, then each coating can address its specific function, but the device complexity increases and neither coating can simultaneously address both corrosion and erosion
Solution Approach 1:
The patent merges corrosion protection and erosion protection into a single composite coating system. The coating comprises a metallic binder matrix containing both hard particles (for erosion resistance) and sacrificial particles (for corrosion protection). This unified structure eliminates the need for multiple separate coating layers while simultaneously addressing both degradation mechanisms.
Solution Approach 2:
The coating employs a composite material structure where a metallic binder contains dispersed hard particles and sacrificial particles. This composite approach allows the single coating to exhibit both erosion resistance (from hard particles) and corrosion protection (from sacrificial particles), resolving the contradiction between functional effectiveness and structural complexity.
2Device complexity
If a single coating addresses both corrosion and erosion, then device complexity is reduced, but existing coatings lack the capability to effectively address both issues simultaneously
Solution Approach 1:
The coating implements local quality by distributing different functional particles throughout the metallic binder matrix. Hard particles are positioned to provide erosion resistance where mechanical impact occurs, while sacrificial particles are distributed to provide localized corrosion protection at the coating-metal interface and exposed surfaces. This spatial distribution of specialized components enables the single coating to effectively address both degradation mechanisms simultaneously.
Solution Approach 2:
The sacrificial particles provide self-service corrosion protection by preferentially corroding to protect the underlying metal substrate. When the coating is breached, the sacrificial particles automatically activate to provide cathodic protection, healing the protective function without requiring external intervention. This self-healing mechanism ensures continuous reliability while maintaining a simple single-coating structure.
3Duration of action of stationary object
If the coating is breached during operation, then protection is lost, but sacrificial particles can provide self-healing to restore protection
Solution Approach 1:
The sacrificial particles are pre-positioned within the coating matrix before operation begins. These particles are prepared in advance to provide cathodic protection should the coating be breached. When damage occurs, the pre-positioned sacrificial particles immediately activate to restore protection, eliminating the need for external repair interventions and extending the effective service life of the coating system.
Solution Approach 2:
The sacrificial particles act as a backup protection mechanism prepared in advance against the harmful event of coating breach. By having this protective capability built into the coating structure beforehand, the system can withstand damage and maintain reliability, effectively cushioning against the loss of protection that would otherwise occur upon coating failure.
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 effectively protects metal components from both corrosion and erosion, maintaining performance even when breached, with the sacrificial particles offering self-healing capabilities and the hard particles enhancing wear resistance.
Implementation Method 1
providing erosion and corrosion resistance through anodic protection and self-healing properties
Implementation Method 2
the hard particles enhancing wear resistance
Data Source
AI summary
Disclosed herein is an erosion and corrosion resistant coating comprising a metallic binder, a plurality of hard particles, and a plurality of sacrificial particles. Also disclosed is a method of improving erosion and corrosion resistance of a metal component comprising disposing on a surface of the metal component the foregoing erosion and corrosion resistant coating comprising, and a metal component comprising a metal component surface and the foregoing erosion and corrosion resistant coating comprising a first surface and a second surface opposite the first surface, wherein the first surface is disposed on the metal component surface.