Additive Layer Manufacturing Core Geometry for Powder Evacuation
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Solution Overview
Problem
The existing manufacturing methods for dual wall components with cooling holes, such as casting, face challenges in ensuring precise location of corners and end surfaces due to manufacturing tolerances, which can lead to incomplete evacuation of core cavities and potential component failure, especially in high-temperature and pressure environments like gas turbine engines.
Innovation Solution
The method involves using additive layer manufacturing (ALM) with a core geometry that includes a main core passage and inclined channels to facilitate the removal of excess material, allowing for the creation of components with improved structural integrity and functionality, such as cooling holes, by upturning the component to remove excess powder through the channel, which can also serve as a cooling conduit or fastener location.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional casting methods with traditional core geometries are used, then manufacturing experience and material properties are maintained, but excess powder becomes trapped in core cavities causing component failure
Solution Approach 1:
The core geometry is segmented into a main passage and multiple inclined channels that divide the evacuation path into sections, allowing powder to be systematically removed through each channel rather than attempting to evacuate the entire cavity through a single point
Solution Approach 2:
The core geometry transitions from conventional horizontal/vertical passages to three-dimensional inclined channels at specific angles (10-75 degrees), creating new evacuation pathways that exploit gravitational and vibrational forces in multiple dimensions to remove trapped powder
2Temperature
If cooling holes are positioned closer to cavity corners to maximize cooling efficiency, then cooling performance improves, but manufacturing tolerances cause holes to miss the cavity
Solution Approach 1:
The patent replaces mechanical machining of cooling holes with post-casting drilling or erosion techniques, allowing the cavity shape to be precisely defined by the ALM process while cooling holes are added afterward without requiring precise pre-positioning
Solution Approach 2:
The core geometry is designed in advance with inclined channels that create an obtuse apex configuration, preliminarily establishing the cavity shape and position before cooling holes are added, ensuring holes will connect to the cavity regardless of subsequent manufacturing variations
3Device complexity
If ALM processes use traditional core geometries, then process simplicity is maintained, but untreated particulate material becomes stuck in core cavity corners altering component design
Solution Approach 1:
The core geometry parameters are changed from conventional horizontal/vertical passages to inclined channels at specific angles (10-75 degrees), fundamentally altering how powder behaves during evacuation and preventing it from becoming trapped in corners
Solution Approach 2:
The inclined channels create smoothly curved transitions and obtuse apex configurations that eliminate sharp corners where powder could become trapped, using curved geometry to guide powder flow continuously toward evacuation openings
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 ensures complete removal of excess material, maintains the mechanical properties of the component, and prevents the sintering of untreated powders, thereby enhancing the performance and reliability of dual wall components in extreme conditions.
Implementation Method 1
the treatment involves local heating using a laser or electron beam. Specific examples of such ALM methods include (without limitation); laser sintering, laser melting and electron beam melting (EBM).
Implementation Method 2
local heating using a laser or electron beam. Specific examples of such ALM methods include (without limitation); laser sintering
Implementation Method 3
Once the component has been built, excess powder can conveniently by removed by upturning the component, facing the exit of the first channel downwards and allowing the excess powder to escape through the first channel.
Implementation Method 4
The removal step may include the use of a vibrating rig.
Data Source
AI summary
A method for the manufacture of a component having an internal cavity is described. The method comprises; defining an external geometry of the component, defining a core geometry of the component; and using an additive layer manufacturing (ALM) method, building the component from a plurality of layers laid on a first plane. The core geometry is advantageously designed to suit manufacture of the component using an ALM method which involves local melting of powder in a powder bed to form the layers, permitting easy removal of excess powder from the internal cavity.