Aluminizing Serpentine Cooling Passages via Slurry Injection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for aluminizing superalloy substrates, such as vapor-phase processes, are costly and time-consuming, especially when applied to complex internal cooling passages in gas turbine components, necessitating a more economical and efficient method for aluminum enrichment.
Innovation Solution
A slurry coating composition comprising aluminum powder and a binder like colloidal silica is injected into internal passages, followed by compressed air distribution and heat treatment to facilitate uniform aluminum diffusion into the substrate surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vapor-phase aluminizing process is used for internal cooling passages, then aluminum enrichment is achieved, but cost and time consumption increase significantly
Solution Approach 1:
The patent uses liquid slurry injection combined with compressed air flow to deliver aluminum coating material through complex internal cooling passages. This hydraulic/pneumatic approach replaces expensive vapor-phase processes, enabling cost-effective aluminizing of internal surfaces by utilizing fluid delivery systems already present in manufacturing.
Solution Approach 2:
The patent changes the physical state of aluminum delivery from gas phase (vapor-phase aluminizing) to liquid phase (slurry injection). This parameter change enables the use of lower-cost liquid delivery systems and compressed air instead of expensive vapor generation and control equipment, while achieving the same aluminum enrichment result.
2Reliability
If vapor-phase aluminizing process is used for internal cooling passages, then aluminum enrichment is achieved, but process time increases
Solution Approach 1:
The liquid slurry injection system with compressed air flow enables rapid delivery and distribution of aluminum coating material through internal passages. This method is faster than vapor-phase processes because liquid injection and air flow distribution occur more quickly than vapor generation, heating, and deposition cycles.
Solution Approach 2:
The aluminum coating material is pre-mixed into liquid slurry form before injection, eliminating the need for in-situ vapor generation and deposition. This preliminary preparation of the coating material in liquid form allows for faster application and reduces overall process time compared to vapor-phase methods that require sequential heating and deposition steps.
3Reliability
If complex internal cooling passages are aluminized using traditional methods, then protective coating is achieved, but manufacturing complexity increases
Solution Approach 1:
The patent utilizes liquid slurry injection and compressed air flow to navigate complex internal cooling passage geometries. This approach simplifies manufacturing by using flexible fluid delivery that can adapt to any passage shape, eliminating the need for complex masking, positioning, or specialized equipment required by traditional vapor-phase or mechanical coating methods.
Solution Approach 2:
The liquid slurry injection system with compressed air distribution serves multiple functions simultaneously: it delivers aluminum coating material, distributes it uniformly throughout complex passages, and enables removal of excess material. This multi-functional approach reduces manufacturing complexity compared to methods requiring separate steps for each function.
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 allows for a cost-effective and efficient aluminizing of internal surfaces, including complex cooling passages, resulting in a uniformly coated and aluminum-enriched surface region, reducing the need for expensive vapor-phase processes.
Implementation Method 1
heat treating the slurry composition under conditions sufficient to remove volatile components from the composition, and to cause diffusion of aluminum into a surface of the internal passage
Implementation Method 2
heat treating the slurry composition under conditions sufficient to remove volatile components from the composition
Implementation Method 3
applying compressed air to the internal passage to facilitate distribution of the slurry composition throughout the internal passage
Data Source
AI summary
Disclosed herein is a method for aluminiding an internal passage of a metal substrate comprising injecting a slurry composition that comprises a powder comprising aluminum, a binder selected from the group consisting of colloidal silica, an organic resin, and a combination thereof, into the internal passage; applying compressed air to the internal passage to facilitate distribution of the slurry composition throughout the internal passage; and, heat treating the slurry composition under conditions sufficient to remove volatile components from the composition, and to cause diffusion of aluminum into a surface of the internal passage.