High-Entropy Alloy Seals for High-Temperature Wear Resistance
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Solution Overview
Problem
Conventional seals in gas turbine engines face challenges in withstanding extreme temperatures and pressures while maintaining favorable wear characteristics, as existing materials like nickel-based alloys are inadequate for high-temperature environments.
Innovation Solution
The use of high entropy alloys, such as MoNbTaW, AlCoCrFeNiTi, or CoCrFeMnNi, formed through additive manufacturing processes like selective laser melting or laser engineered net shaping, which create a seal body with complex geometries and provide tribological and creep resistance, enabling operation up to 900°C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional nickel-based alloys are used for seals in gas turbine engines, then the seals can provide basic sealing function, but they cannot withstand extreme temperatures and pressures while maintaining favorable wear characteristics
Solution Approach 1:
The patent changes the material composition parameters by using high entropy alloys with specific elemental ratios (e.g., Cr: 20-30 wt%, Mn: 15-25 wt%, Fe: 15-25 wt%, Co: 10-20 wt%, Ni: 5-15 wt%, Mo: 5-15 wt%, Nb: 5-15 wt%, Ta: 5-15 wt%, W: 5-15 wt%) to achieve both high-temperature resistance and wear resistance simultaneously, overcoming the limitations of conventional nickel-based alloys
Solution Approach 2:
The patent employs composite material strategy by creating high entropy alloys that combine multiple principal elements (at least five different elements in near-equimolar or wide-range compositions) to achieve synergistic effects that provide both creep resistance at high temperatures and tribological resistance, which single-phase conventional alloys cannot achieve
2Temperature
If seals are designed to withstand extreme environments, then temperature and pressure resistance improve, but wear characteristics deteriorate
Solution Approach 1:
The patent optimizes compositional parameters within specific ranges (e.g., Cr: 20-30 wt%, Mn: 15-25 wt%, Fe: 15-25 wt%, Co: 10-20 wt%, Ni: 5-15 wt%, Mo: 5-15 wt%, Nb: 5-15 wt%, Ta: 5-15 wt%, W: 5-15 wt%) to achieve a balance between high-temperature strength and tribological properties, ensuring both creep resistance and wear resistance are maintained simultaneously
Solution Approach 2:
The patent applies local quality principle by incorporating specific element combinations and ratios in different regions of the alloy structure, creating zones with optimized properties for both high-temperature resistance and wear resistance, allowing the seal to perform optimally under combined thermal and mechanical loading conditions
3Ease of manufacture
If additive manufacturing is used to create seal bodies with complex geometries, then manufacturing capability improves, but material selection becomes more critical for maintaining tribological properties
Solution Approach 1:
The patent uses high entropy alloy composite materials that are specifically designed for additive manufacturing processes, combining multiple principal elements in controlled ratios to ensure that the resulting printed parts maintain excellent tribological properties and creep resistance, addressing the material selection challenge inherent in additive manufacturing of complex seal geometries
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 high entropy alloy seals exhibit low wear and friction, extending the interval between overhauls and reducing component replacement, while maintaining effective sealing and wear resistance at both high and low temperatures.
Implementation Method 1
the seal body is formed from a high entropy alloy material and exhibits a low wear and friction
Implementation Method 2
exhibiting favorable wear characteristics and creep resistance
Data Source
Figure 1
Figure 2~4
Figure 5~7
AI summary
A tribological and creep resistant system configured to operate at temperatures in excess of 700°C. A seal body extends between a leading edge (80) and a trailing edge (82). A first component contact surface is adjacent the leading edge (80) and a second component contact surface is adjacent the trailing edge (82). The seal body is formed from a high entropy alloy.