Oxide Ceramic Joint for Heat-Resistant Ceramic-Metal Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing joined bodies with metallic joining layers face issues of low heat resistance, low oxidation resistance, and unreliable joining, especially at high temperatures in air, due to unstable brazing filler performance.
Innovation Solution
A joined body is formed using an oxide ceramic of a transition metal that stably joins ceramic and metal members, or ceramic to ceramic, and metal to metal, with the oxide ceramic penetrating into porous ceramics to create a strong and reliable bond, allowing for high-temperature stability and oxygen resistance without the need for complex atmosphere control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metallic joining layer is used to join ceramic and metal members, then joining is achieved, but heat resistance and oxidation resistance are reduced
Solution Approach 1:
The patent changes the material parameter from metallic joining layer to oxide ceramic layer, fundamentally altering the chemical composition and properties of the joining layer to achieve both reliable joining and high heat resistance
Solution Approach 2:
The patent uses a composite structure where oxide ceramic serves as the joining layer between ceramic and metal members, combining the advantages of ceramic materials (heat resistance, oxidation resistance) with joining functionality
2Ease of manufacture
If brazing filler is used to join non-oxide ceramic and metal, then joining is achieved, but joining stability at high temperatures in air is reduced
Solution Approach 1:
The patent changes the chemical composition parameter of the joining layer from metallic brazing filler to oxide ceramic, which fundamentally improves chemical stability and oxidation resistance at high temperatures while maintaining joining capability
3Reliability
If high firing temperature is used to join members, then joining is achieved, but process complexity and energy consumption increase
Solution Approach 1:
The patent changes the chemical state parameter of the joining material from metallic to oxidized state, allowing joining to proceed at lower temperatures since the oxide ceramic can form stable bonds without requiring extreme thermal energy
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 oxide ceramic joint provides enhanced reliability and stability at high temperatures, maintaining strong joining and electrical conductivity, even with members having different thermal expansion coefficients, and allows for simpler and more reliable joining processes in air.
Implementation Method 1
the oxide ceramic penetrates into the pores of the porous ceramic and strongly combines a joining layer with the porous ceramic
Implementation Method 2
when fired in the air, the raw material becomes less reactive through oxidation of the metal, thereby preventing the incorporated component of the member from excessively diffusing into the joint
Implementation Method 3
maintaining strong joining and electrical conductivity
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A joined body 20 according to the present invention includes a first member 22 made of a porous ceramic, a second member 24 made of a metal, and a joint 30 formed of an oxide ceramic of a transition metal, the joint 30 joining the first member 22 to the second member 24. Alternatively, a joined body may include a first member made of a dense material, a second member made of a dense material, and a joint formed of an oxide ceramic of a transition metal, the joint joining the first member to the second member.