Heat-Resistant Metal Oxide Ceramic Coating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing heat-resistant members face issues with insufficient bondability between metal surfaces and ceramic layers, limited electrical conductivity at high temperatures, and difficulties in increasing film thickness, particularly in applications requiring high thermal and electrical performance.
Innovation Solution
A heat-resistant member is created by forming a metal oxide ceramic protective layer with porosity between 0% to 5% volume on a metal or ceramic substrate through firing in air, enhancing bondability and stability under high temperatures while maintaining electrical conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a ceramic powder of an oxide is formed on the surface of a metal, then the insulating property is improved, but the bondability between the metal surface and the first layer becomes insufficient
Solution Approach 1:
The protective layer is divided into multiple layers: a first protective layer with higher porosity (10-50 vol%) formed directly on the metal substrate for good bondability, and a second protective layer with lower porosity (0-10 vol%) formed on the first protective layer for superior insulating properties. This segmentation allows each layer to optimize its function without compromising the other.
Solution Approach 2:
Different regions of the protective coating have different porosity characteristics tailored to their specific functions. The first protective layer near the metal substrate has higher porosity to facilitate bonding and stress relief, while the second protective layer at the outer surface has lower porosity to provide excellent insulation. Each layer's local structure is optimized for its specific role in the overall system.
2Reliability
If an insulating film is formed on the metal, then the insulating property is improved, but the electrical conductivity at high temperature cannot be utilized
Solution Approach 1:
The protective coating structure provides different functional properties at different locations: the first protective layer with higher porosity allows for electrical conductivity and heat dissipation near the substrate, while the second protective layer with lower porosity provides superior insulation at the outer surface. This local differentiation enables the system to maintain electrical conductivity where needed while providing insulation where required.
Solution Approach 2:
The protective coating is constructed as a composite structure with two distinct ceramic layers having different porosity characteristics. This composite approach combines the advantages of both high-porosity structures (electrical conductivity, bonding) and low-porosity structures (insulation), enabling the system to achieve both electrical conductivity and insulating properties in different regions simultaneously.
3Reliability
If a ceramic film is formed by aerosol deposition or plasma spraying method, then the insulating property is improved, but there are many limitations to the steps and the film thickness cannot be increased easily
Solution Approach 1:
The protective coating is formed by applying ceramic slurry and drying it in a continuous process without requiring complex atmospheric control or multiple discrete steps. The slurry application can be done by simple coating methods, and the drying process naturally forms the desired porous structure. This continuous, simplified process allows for easy thickness control and scaling without the limitations of aerosol deposition or plasma spraying.
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 method reduces changes in characteristics, such as electrical conductivity and oxidation resistance, and allows for simpler production of heat-resistant members with improved high-temperature stability and electrical performance without the need for complex atmosphere control.
Implementation Method 1
firing a member provided with a metal raw material in the air in a temperature range lower than the melting point of an oxide of the above-described metal raw material to form a metal oxide ceramic protective layer
Implementation Method 2
the protective layer and the member to be protected can be bonded in the state in which, for example, the component of the member to be protected is taken in and this component is diffused
Data Source
AI summary
A heat-resistant member according to the present invention includes a member to be protected and a metal oxide ceramic protective layer which is disposed on part of or all surfaces of the member to be protected and which has a porosity of 0 percent by volume or more and 5 percent by volume or less. This heat-resistant member is produced through the step of forming a protective layer by firing a member to be protected provided with a metal raw material in the air in a temperature range lower than the melting point of an oxide of the metal raw material to form a metal oxide ceramic protective layer having a porosity of 0 percent by volume or more and 5 percent by volume or less on part of or all surfaces of the member to be protected.