DED Repair Microstructure Control for Aerospace Part Integrity
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Solution Overview
Problem
Existing repair techniques for aerospace components, such as gas turbine engine components, are inadequate for components that require structural integrity and cannot be repaired using currently known methods.
Innovation Solution
A directed energy deposition (DED) process is used to create layers with controlled microstructures by adjusting parameters like powder feed rate, energy intensity, traversal rate, and auxiliary heating/cooling to form repair layers with predetermined properties, enabling repair of components that were previously unrepairable.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional repair techniques are used on aerospace components, then the repair process is simple and accessible, but the structural integrity and reliability of the repaired component are insufficient
Solution Approach 1:
The repair process is segmented into multiple controlled layers, where each layer is deposited and consolidated separately with specific microstructural requirements. This allows precise control over the microstructure of each layer to ensure overall structural integrity while maintaining a systematic approach to the complex repair process.
Solution Approach 2:
The patent applies parameter changes by controlling multiple DED process parameters including powder feed rate, energy intensity, traversal rate, and auxiliary heating/cooling to impart predetermined microstructures to each repair layer. This enables achievement of high structural integrity through scientifically controlled material deposition and consolidation.
2Duration of action of stationary object
If directed energy deposition with controlled microstructure is used, then the structural integrity and service life are enhanced, but the repair process becomes more complex and requires precise control of multiple parameters
Solution Approach 1:
The patent systematically controls multiple DED process parameters (powder feed rate, energy intensity, traversal rate, auxiliary heating/cooling) to achieve predetermined microstructures in each repair layer. This multi-parameter control enables enhanced service life through optimized material properties while providing a framework for managing the complexity of precise microstructure control.
Solution Approach 2:
Different microstructures are imparted to different repair layers based on their specific functional requirements and position in the component. This local quality approach allows each layer to be optimized for its specific role, extending the overall service life of the component while maintaining manageable complexity through localized control strategies.
3Reliability
If multiple repair layers with predetermined microstructures are deposited, then the reliability and performance of the repaired component are improved, but the repair time and process duration increase
Solution Approach 1:
The repair process is divided into multiple layers that can be deposited and consolidated in a systematic sequence. This segmentation allows for efficient process planning and execution, where each layer contributes to the overall reliability while the structured approach minimizes unnecessary delays compared to unstructured multi-layer processes.
Solution Approach 2:
The DED process enables continuous deposition and consolidation of repair layers without complete interruption between layers. This continuity of useful action maintains high component reliability through proper microstructural development while minimizing idle time between layers, thereby reducing overall repair time compared to discontinuous repair methods.
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 DED process enhances the structural integrity and extends the service life of repaired aerospace components by providing controlled microstructures that meet operational requirements.
Implementation Method 1
A repair procedure is performed on the repair region using a directed energy deposition (DED) energy/powder head. The repair procedure includes depositing, using the DED energy/powder head, a first layer of DED powder material in the repair region; melting and consolidating, using energy from the DED energy/powder head, the first layer of DED powder material
Implementation Method 2
The microstructure of each of the plurality of repair layers is imparted using selected levels of DED powder material feed to the repair region, intensity of energy directed from the DED energy/powder head to the repair region, rate at which the DED energy/powder head traverses the repair region, and auxiliary heating and/or cooling provided to the repair region
Implementation Method 3
The microstructure of each of the plurality of repair layers is imparted using selected levels of DED powder material feed to the repair region, intensity of energy directed from the DED energy/powder head to the repair region, rate at which the DED energy/powder head traverses the repair region, and auxiliary heating and/or cooling provided to the repair region
Data Source
Figure 1
Figure 2
AI summary
An aerospace part (10), which is made from a base material, is inspected to identify a worn or defective repair region (20) that requires repair. A repair procedure is performed on the repair region (20) using a directed energy deposition (DED) energy/powder head (18). The repair procedure includes depositing, using the DED energy/powder head (18), a first layer of DED powder material in the repair region (20); melting and consolidating, using energy from the DED energy/powder head (18), the first layer of DED powder material to form a first repair layer (14) having a first pre-determined microstructure; and repeating the depositing and melting and consolidating steps to create a desired plurality of repair layers (14). Each of the plurality of repair layers (14) has a pre-determined microstructure. The microstructure of each of the plurality of repair layers (14) is imparted using selected levels of DED powder material feed to the repair region (20), intensity of energy directed from the DED energy/powder head (18) to the repair region (20), rate at which the DED energy/powder head (18) traverses the repair region (20), and auxiliary heating and/or cooling provided to the repair region (20). The aerospace part (10) is returned to service after completion of the desired repair.