Oxide Ceramic Joining Layer for High-Temperature Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing joined bodies face issues with low heat resistance, oxidation resistance, and joining reliability due to the use of metal-based joining layers, and honeycomb structural bodies with electrode materials like Cu, Al, and Si exhibit inadequate heat and oxidation resistance, leading to degraded electrical conductivity and uneven heat generation.
Innovation Solution
A joined body is formed using an oxide ceramic with a Fe3O4 phase, where a solute component capable of forming a spinel-type oxide with Fe is solid-dissolved, and a joint layer is created by firing a laminate of Fe metal powder and solute component powder, enhancing thermal stability and electrical conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal-based joining layer is used to join members, then the joining process is simple and effective, but the heat resistance, oxidation resistance, and joining reliability are low
Solution Approach 1:
The patent changes the material parameter from metal-based to oxide ceramic-based joining layer, specifically using Fe3O4 phase with solid-dissolved solute components. This parameter change transforms the chemical composition and crystal structure, enabling the joining layer to maintain stability at high temperatures while achieving reliable joining, thus resolving the contradiction between joining reliability and heat resistance
Solution Approach 2:
The patent creates a composite oxide ceramic material by solid-dissolving solute components (such as Ni, Co, Mn, Zn, or Ca) into the Fe3O4 phase. This composite structure combines the high heat resistance of Fe3O4 with the beneficial properties of the solute components, achieving both high joining reliability and excellent heat resistance simultaneously
2Reliability
If electrode materials like Cu, Al, or Si are used in honeycomb structural bodies, then the electrical conductivity is good, but the heat resistance and oxidation resistance are inadequate
Solution Approach 1:
The patent changes the material parameter from conventional electrode materials (Cu, Al, Si) to oxide ceramic materials with Fe3O4 phase containing solid-dissolved solute components. This parameter change maintains electrical conductivity while dramatically improving oxidation resistance and heat resistance, as the oxide ceramic structure is inherently stable in oxidizing environments at high temperatures
3Reliability
If a metal layer with Cr and/or Fe is used to ensure electrical connection reliability, then the electrical connection reliability is ensured, but the oxidation resistance is low
Solution Approach 1:
The patent creates a composite oxide ceramic material where solute components (Cr, Fe, Ni, Co, Mn, Zn, or Ca) are solid-dissolved in the Fe3O4 phase. This composite structure maintains the electrical conductivity benefits of Fe and Cr while the oxide ceramic matrix provides superior oxidation resistance, resolving the contradiction between electrical connection reliability and oxidation resistance
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 provides a more reliable and stable joining of members with improved electrical conductivity and heat resistance, preventing degradation and ensuring uniform heat distribution in honeycomb structural bodies.
Implementation Method 1
an oxide ceramic containing a Fe3O4 phase in which a solute component capable of forming a spinel-type oxide with Fe is solid-dissolved
Implementation Method 2
a joint layer is created by firing a laminate of Fe metal powder and solute component powder
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
A joined body 20 includes a first member 21, a second member 22, and a joint portion 30 which is formed from an oxide ceramic containing a Fe3O4 phase in which a solute component capable of forming a spinel-type oxide with Fe is solid-dissolved and which joins the first member 21 and the second member 22.