Plasma Powder Injection Layout for Uniform Multi-Powder Coatings
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Solution Overview
Problem
Existing plasma spraying methods for environmental barrier coatings (EBCs), thermal barrier coatings (TBCs), and abradable coatings in turbomachinery result in nonhomogeneous distribution and layering of constituents due to differences in density and morphology of powder particles, leading to undesirable coating properties.
Innovation Solution
A method and device for plasma spraying where powders with different properties are introduced at varying distances and points along the plasma jet path using separate injector lines, allowing controlled flow and uniform distribution of materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If multiple powder compositions with differing physical and chemical properties are introduced into the plasma jet as a blended mixture, then the coating formation process is simplified, but the distribution of materials becomes nonhomogeneous and layering occurs
Solution Approach 1:
The invention divides the single blended powder introduction into multiple separate powder introduction streams. Each powder composition is introduced through its own injector at a specific location along the plasma jet path, segmenting the material feed system to prevent mixing-related flow issues while maintaining process simplicity
Solution Approach 2:
The invention transitions from introducing all powders at a single point (zero-dimensional mixing point) to introducing powders at multiple locations along the plasma jet path (one-dimensional spatial distribution). This dimensional change allows each powder to be introduced at an optimized position, ensuring homogeneous distribution despite differences in physical and chemical properties
2Device complexity
If powders are introduced at the same point into the plasma jet, then the device complexity is reduced, but the flow patterns of different constituents become unpredictable and nonuniform
Solution Approach 1:
The powder introduction system is segmented into multiple independent injection points along the plasma jet path. Each injector handles a specific powder composition, creating predictable and controlled flow patterns for each constituent rather than relying on chaotic mixing at a single point
Solution Approach 2:
The invention performs preliminary positioning of each powder stream at specific locations along the plasma jet path before the powders converge and mix in the coating formation zone. This preliminary spatial arrangement ensures that each powder follows a predictable flow trajectory, establishing consistent flow patterns before mixing occurs
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 approach enhances the uniformity and microstructure of coatings, reducing segregation and layering, and provides flexibility in controlling the flow of particles, resulting in improved coating properties.
Implementation Method 1
generating a plasma jet using a plasma spray torch
Implementation Method 2
generating a plasma jet using a plasma spray torch having a nozzle through which the generated plasma jet is discharged
Implementation Method 3
introducing a first powder into the plasma jet... introducing a second powder into the plasma jet
Data Source
AI summary
A method and device are described for plasma spraying of multiple powders. A first powder is introduced into a plasma jet at a first distance from the nozzle of a plasma spray torch. A second powder is introduced into the plasma jet at a second distance from the nozzle of the plasma spray torch. The second distance is greater than the first distance so that the second powder is introduced into the plasma jet at a different point than which the first powder enters the plasma jet. The method and device can be used to simultaneously plasma spray different powders that have, for example, different compositions and/or different particle morphology.