Gas Turbine Blade Manufacturing with Temporary Support Ribs
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Solution Overview
Problem
The manufacture of gas turbine engine blades using metal powder injection molding faces challenges due to significant shrinkage, which affects dimensional accuracy and introduces deformations or cracks, especially in asymmetrical blades with varying thicknesses, leading to material loss and increased production costs.
Innovation Solution
A method involving the injection of a metal or ceramic powder mixture with a binder, followed by debinding and heat treatment, where protuberances (such as ribs) are used to support and stiffen the blade during manufacturing, controlling dimensions and reducing material loss by up to 27% and preventing deformation phenomena like sagging and buckling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If metal powder injection molding is used to manufacture gas turbine engine blades, then production rate and repeatability are improved, but dimensional accuracy deteriorates due to shrinkage of up to 15%
Solution Approach 1:
The invention applies preliminary action by designing the mold cavity with compensating dimensions that anticipate the shrinkage that will occur during sintering. The mold is configured to produce a green part with dimensions that, after predictable shrinkage, will result in the desired final blade dimensions. This pre-planned compensation resolves the dimensional accuracy issue while maintaining the productivity benefits of injection molding.
Solution Approach 2:
The invention utilizes parameter changes by systematically adjusting and controlling the sintering parameters (temperature, atmosphere, time, heating rate) to minimize dimensional variations and shrinkage. By optimizing these thermal parameters, the process achieves both high productivity and improved dimensional accuracy, resolving the contradiction between production rate and manufacturing precision.
2Shape
If metal powder injection molding is used for asymmetrical blades with varying thicknesses, then complex shapes can be produced, but deformations and cracks increase due to thermal variations during manufacturing
Solution Approach 1:
The invention applies preliminary action by designing support structures (ribs, protrusions) into the blade geometry before manufacturing. These features are strategically positioned to provide thermal support and stiffness during the injection molding and sintering processes, preventing deformations and cracks in the asymmetrical, varying-thickness blade sections before the actual manufacturing begins.
Solution Approach 2:
The invention implements beforehand cushioning by incorporating support ribs and protrusions that act as internal reinforcement during manufacturing. These features cushion the blade structure against thermal stresses and deformations that occur during injection molding and sintering, particularly in the thin-walled asymmetrical sections, thereby preventing cracks and maintaining reliability.
3Manufacturing precision
If protuberances are added to support the blade during manufacture, then dimensional control and prevention of deformation are improved, but device complexity increases
Solution Approach 1:
The invention applies the taking out principle by designing the protuberances and support ribs to be temporary manufacturing features that are removed or trimmed after the blade is formed and cooled. These support features are extracted from the final product, allowing the blade to achieve the desired complex shape without permanent additional geometry, thus maintaining dimensional control during manufacturing while minimizing final device complexity.
4Loss of substance
If traditional manufacturing methods are used, then material loss is high, but metal powder injection molding causes shrinkage and dimensional inaccuracy
Solution Approach 1:
The invention utilizes parameter changes by optimizing the powder mixture composition (binder content, powder size distribution, particle morphology) and controlling the injection molding and sintering parameters to minimize both material loss and dimensional inaccuracy. By systematically adjusting these parameters, the process achieves near-net-shape manufacturing with reduced material waste while maintaining dimensional control through compensating design.
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 enables the reliable and efficient production of complex, asymmetrical gas turbine engine blades with improved dimensional control and reduced material loss, while maintaining a high production rate and optimized budget, resulting in blades with enhanced resistance to creep and reduced material waste.
Implementation Method 1
injection of a mixture comprising a binder and a powder, the powder comprising at least one metal or ceramic
Implementation Method 2
a debinding of the part is carried out so as to eliminate a greater part of the binder from the part
Implementation Method 3
This part where nearly all of the binder has been removed is very fragile because it is composed of approximately 40% air, and is only bound by the remains of the binder. The brown part is finally sintered, step during which it is subjected to a temperature close to the melting point of the powder. This temperature allows the grains to weld together to create a solid.
Data Source
AI summary
The invention relates to a process for manufacturing a turbomachine blade, wherein: —a part (4) is manufactured comprising a foot (4), a heel (6) and an air stream zone (10) extending between the foot and the heel, the air stream zone comprising at least one protuberance (20, 24, 26) projecting from a main face (12) of the zone, the manufacturing being performed by injecting a mixture comprising a binder and a powder, the powder comprising at least a metal or a ceramic: —debinding is performed on the part so as to eliminate a greater quantity of the binder from the part: —heat treatment is performed on the part; and—the or each protuberance is eliminated from the air stream zone.