Surface Component Repair Using Solid-State Diffusion Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional repair methods for high temperature components in gas turbine engines, such as brazing, fail to form a microstructural bond with the base material and introduce undesirable phases like silicides and borides, leading to inadequate durability and reliability.
Innovation Solution
A repair method involving a feedstock mixture of base material particles and a binder, with optional melting point depressant, formed into a preform that is subjected to thermal cycles below the melting temperature to create a metallurgical bond in a solid state, avoiding fusion and thus minimizing the formation of undesirable phases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional brazing techniques are used to repair high temperature components, then the repair process can be performed, but the brazing material does not form a microstructural bond with the base material and introduces undesirable phases such as silicides and borides
Solution Approach 1:
The invention changes the fundamental parameter of the bonding process from fusion-based (brazing) to solid-state diffusion bonding. This parameter change eliminates the formation of undesirable phases while achieving reliable microstructural bonding between the repair material and base material.
Solution Approach 2:
The invention replaces the thermal-mechanical brazing process with a solid-state diffusion bonding process. This substitution eliminates the harmful effects of melting and phase formation while achieving equivalent or superior bond quality through diffusion mechanisms.
2Ease of manufacture
If conventional brazing techniques are used to repair high temperature components, then the repair can be completed, but the brazing material may not withstand the operating conditions of the component
Solution Approach 1:
The invention uses base material particles as the feedstock, ensuring that the repair material has the same composition and properties as the base material. This homogeneity ensures that the repaired area can withstand the same operating conditions as the original component.
Solution Approach 2:
The invention creates a composite structure during the repair process, where base material particles are embedded in a binder matrix that is subsequently removed. The final repair material is essentially pure base material, ensuring compatibility with operating conditions.
3Reliability
If solid state diffusion bonding is used to form a metallurgical bond, then a microstructural bond is formed that matches the base material properties, but the process requires precise temperature control below melting point
Solution Approach 1:
The invention specifies a temperature range that is high enough to enable diffusion bonding but low enough to prevent melting. This parameter optimization achieves reliable bonding while avoiding the complexity of precise melting-point control.
Solution Approach 2:
The binder material serves as an intermediary that holds the base material particles in place during the bonding process. This intermediary allows for easier temperature control since the binder protects the particles from direct exposure to extreme temperatures.
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 enhances the mechanical strength and durability of the repaired components by forming a metallurgical bond that matches the properties of the base material, extending the service life of high temperature components without introducing harmful phases.
Implementation Method 1
solidifying the fluid feedstock mixture to obtain a solidified feedstock mixture on the damaged portion of the surface of the component
Implementation Method 2
subjecting the component and the solidified feedstock mixture to at least one thermal cycle for forming a metallurgical bond in a solid state between the solidified feedstock mixture and the surface of the component after the at least one thermal cycle, the at least one thermal cycle occurring below a melting temperature of the component and the solidified feedstock mixture
Implementation Method 3
the obtaining of the feedstock mixture includes applying a vacuum, mixing and heating the feedstock mixture above a melting point of the binder
Data Source
Figure 1
Figure 2A~2E
Figure 3
AI summary
A repair method for a component having a damaged portion on a surface thereof includes obtaining a feedstock mixture comprising base material particles and a binder, forming a preform with the feedstock mixture, placing the preform on the damaged portion of the surface of the component, and subjecting the component and the preform to at least one thermal cycle for forming a metallurgical bond in a solid state between the preform and the surface of the component after the at least one thermal cycle, the at least one thermal cycle occurring below a melting temperature of the component and the preform. A repair method involving pouring fluid feedstock mixture on a damaged portion of the surface of the component is also disclosed.