Temperature Resistant Sol-Gel Coating for Aerospace
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sol-gel films used in aerospace applications are susceptible to corrosion and require chromates, which are under regulatory pressure for elimination, and lack durability at elevated temperatures, leading to cracking and discoloration.
Innovation Solution
A sol-gel mixture comprising a combination of organosilanes and a hydrophobic agent, with a specific molar ratio and curing process, forming a cross-linked siloxane film that is free from chromates and metal oxides, providing enhanced corrosion resistance and thermal stability up to 450°F (232°C).
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chromates are used as corrosion inhibitors in sol-gel films, then corrosion resistance is improved, but regulatory compliance deteriorates due to pressure to eliminate hexavalent chromium
Solution Approach 1:
The patent removes chromates and metal oxides from the sol-gel film composition entirely, replacing them with alternative corrosion inhibitors such as organic carboxylic acids and their salts, thereby eliminating the harmful substance while maintaining protective function
Solution Approach 2:
The patent changes the chemical composition parameters of the sol-gel system by substituting chromate-based inhibitors with organic acid-based inhibitors, altering the film's chemical properties to achieve both corrosion protection and regulatory compliance
2Reliability
If conventional sol-gel films are used at elevated temperatures, then initial corrosion protection is provided, but thermal stability deteriorates leading to cracking and discoloration
Solution Approach 1:
The patent creates a composite sol-gel system combining multiple organosilanes with specific functional groups (ether, ester, amine) that work synergistically to provide both corrosion inhibition and high-temperature stability, preventing the cracking and discoloration seen in conventional films
Solution Approach 2:
The patent modifies the sol-gel composition by incorporating specific ratios of organosilanes with different functional groups and adding hydrophobic agents, changing the physical and chemical parameters to achieve enhanced thermal resistance up to 450°F while maintaining corrosion protection
3Reliability
If sol-gel films are applied to metal substrates, then corrosion resistance is improved, but application complexity increases due to multiple processing steps
Solution Approach 1:
The patent combines multiple functions (corrosion inhibition, hydrophobicity, thermal stability) into a single sol-gel coating formulation that can be applied in one step, eliminating the need for separate chromate treatment and topcoat application steps
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 sol-gel film maintains hydrophobicity and corrosion resistance at elevated temperatures, reducing cracking and discoloration, while being easier to apply and repair, thus lowering maintenance and production costs.
Implementation Method 1
forming a cross-linked siloxane film
Implementation Method 2
The sol-gel mixture is cured to form a sol-gel
Implementation Method 3
A hydrophobic agent is added to the sol-gel mixture. The sol-gel mixture is cured to form a sol-gel
Data Source
Figure 1~2
Figure 3A~3B
Figure 4A~4D
AI summary
The present disclosure provides a sol-gel the present disclosure provides a sol-gel that is a crosslinked siloxane. The sol-gel includes a first siloxane unit represented by formula (1): wherein X is an oxygen, R1 is a hydrogen, oxygen, hydroxyl, or silane group, R2 is a hydrogen, hydroxyl, or silane group, each of R3 and R4 is independently linear or branched C1-20 alkyl, C1-20 cycloalkyl, oxysilane, ether, epoxide, aryl alkylfluroide, cycloalkylfluoride, and arylfluoride groups, and n is 1 to 100. The sol-gel includes a second siloxane unit represented by formula (1), wherein the second siloxane unit is different than the first siloxane unit. The sol-gel includes a hydrophobic agent represented by formula (1), wherein the hydrophobic agent comprises at least one alkylflouride group.