Titanium Compressor Case Fire Resistance via High Heat Capacity Liner
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Titanium and titanium alloys used in gas turbine engines are prone to ignition and fires due to friction and oxidation, leading to weight and cost issues with current superalloy or thick-walled titanium constructions.
Innovation Solution
A high thermal conductivity material with compatible coefficient of thermal expansion is applied as a liner to titanium components, accompanied by a diffusion barrier to prevent detrimental phase formation and ignition, reducing the risk of fire while maintaining low weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If superalloy or steel materials are used for compressor cases, then fire resistance is improved, but weight increases
Solution Approach 1:
The invention uses a composite structure consisting of a titanium base material with a deposited layer of high specific heat capacity material. This composite approach combines the low weight advantage of titanium with the fire resistance benefits of high specific heat materials, resolving the contradiction between weight and fire resistance.
Solution Approach 2:
The high specific heat material is deposited only in specific areas where rubbing or ignition risk is predicted to occur, rather than coating the entire compressor case. This localized approach provides fire protection where needed while minimizing the overall weight increase.
2Reliability
If thick-walled titanium construction is used, then fire resistance is improved, but weight increases
Solution Approach 1:
Instead of increasing titanium wall thickness, the invention deposits a layer of high specific heat material on the titanium surface. This provides fire resistance through material properties rather than increased thickness, avoiding the weight penalty of thick-walled construction.
Solution Approach 2:
The invention changes the surface material parameters by depositing high specific heat material with different thermal properties than titanium. This alters the thermal response characteristics to resist ignition without requiring increased base material thickness.
3Reliability
If exotic thermal barrier coating systems are applied, then fire resistance is improved, but cost increases
Solution Approach 1:
The high specific heat material is deposited only in areas where rubbing or ignition is predicted to occur, rather than applying exotic TBC systems across the entire component. This localized deposition reduces material costs and manufacturing complexity.
Solution Approach 2:
The invention uses readily available high specific heat materials deposited in a controlled manner, replacing expensive exotic TBC systems. The approach uses simpler, more cost-effective materials while achieving the desired fire protection function.
4Reliability
If high specific heat material is applied to titanium, then fire resistance is improved, but detrimental phase formation may occur
Solution Approach 1:
A diffusion barrier layer is introduced as an intermediary between the titanium base material and the high specific heat material layer. This barrier prevents detrimental interdiffusion and phase formation while allowing the high specific heat material to provide fire resistance on the surface.
Solution Approach 2:
The invention creates a three-layer composite structure: titanium base material, diffusion barrier layer, and high specific heat material layer. This composite structure maintains the stability of each layer while achieving the desired fire resistance properties.
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 solution effectively reduces the likelihood of titanium fires in high-pressure compressor cases, achieving a significant weight reduction and improved thermal management without the need for exotic coatings, while maintaining structural integrity and preventing localized melting.
Implementation Method 1
A component comprising a titanium or titanium alloy base material (Ti) further comprises a high specific heat material overlying at least a portion of the titanium or titanium alloy base material
Implementation Method 2
its primary purpose is to reduce the effect of heat due to friction from rub events or from impingement of molten titanium
Implementation Method 3
A diffusion barrier is intermediate the high specific heat material and the titanium or titanium alloy base material, the diffusion barrier being a thin layer overlying the titanium or titanium alloy base material and underlying the high specific heat base material
Implementation Method 4
A layer of material of high thermal conductivity material forming an integral liner is applied to the titanium or titanium alloy component
Implementation Method 5
Titanium and its alloy find particular use in the multiple stages of the compressor section... The limiting temperature in a compressor of titanium and its alloys is about 900°-1000° F., which is well below the ignition point of titanium. This limit is due to the creep strength of titanium and its alloys at temperatures above about 900°-1000° F. and higher, and its propensity to slowly absorb oxygen at these higher temperatures and gradually embrittle over time
Data Source
AI summary
A titanium-based component having a high heat capacity surface. The high heat capacity surface prevents or inhibits titanium fires. The component is titanium-based, forming the substrate, and includes a high heat capacity surface overlying the titanium substrate. A diffusion barrier is intermediate the titanium-based substrate and the high heat capacity surface. The diffusion barrier is non-reactive with both the titanium-based substrate and the high heat capacity surface. The system eliminates the formation of detrimental phases due to diffusion between the applied high heat capacity surface and the titanium substrate. The high heat capacity material has a coefficient of thermal expansion compatible with the coefficient of thermal expansion of the titanium-based substrate. The stresses introduced into the component as a result of differential thermal expansion between the high heat capacity material and the titanium-based substrate do not result in spalling of the substrate at the operational temperatures of the component.