Ceramic Honeycomb Filter Plugs with Amorphous Oxide Matrix
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ceramic honeycomb filters for diesel engine exhausts face challenges in thermal shock resistance due to differences in thermal expansion coefficients between the sintered ceramic honeycomb body and plugs, leading to cracking and peeling issues under temperature and mechanical stress.
Innovation Solution
A ceramic honeycomb filter with plugs formed from a plugging material containing ceramic particles and colloidal oxide, where the colloidal oxide is converted to an amorphous oxide matrix at low temperatures, reducing residual stress and thermal expansion coefficient differences with the sintered ceramic honeycomb body.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If plugs are formed from conventional cordierite ceramic material and heated to high temperatures (1300°C or higher) to bond to the sintered ceramic honeycomb body, then the plugs achieve sufficient bonding strength, but large residual stress is generated at the interfaces between plugs and honeycomb body due to thermal expansion coefficient differences, causing cracking and peeling
Solution Approach 1:
The invention changes the material composition parameters of the plugging material by incorporating glass phase forming components (such as boron oxide, aluminum oxide, silicon dioxide) in specific proportions. This compositional parameter change enables the material to bond at lower temperatures (below 1300°C) while achieving appropriate bonding strength without generating excessive residual stress, thus resolving the contradiction between bonding strength and thermal shock resistance
Solution Approach 2:
The invention uses a composite plugging material consisting of multiple components: cordierite particles, glass phase forming components (boron oxide, aluminum oxide, silicon dioxide), and binding agents. This composite material structure allows the plugs to have both sufficient bonding strength to the honeycomb body and matched thermal expansion coefficients, preventing cracking and peeling under thermal shock conditions
2Manufacturing precision
If plugging material is heated to high temperatures to convert cordierite-forming material to cordierite, then complete sealing of flow path open ends is achieved, but thermal expansion coefficient mismatch between plugs and honeycomb body increases due to random orientation of cordierite crystals in plugs
Solution Approach 1:
The invention applies different material characteristics to different parts of the plug structure. The glass phase forming components are specifically added to the plugging material to create a localized bonding layer at the interface between the plug and honeycomb body. This local quality enhancement provides both complete sealing and thermal expansion matching without requiring the entire plug to have uniformly oriented crystals
Solution Approach 2:
The glass phase forming components act as an intermediary substance between the cordierite particles and the honeycomb body. These components form a bonding matrix that seals the flow path openings completely while also serving as a thermal expansion buffer, reducing the mismatch between the plug and honeycomb body through its intermediate thermal properties
3Strength
If conventional sintering processes are used to form plugs, then bonding to honeycomb body is achieved, but production costs increase due to high temperature requirements (1300°C or higher)
Solution Approach 1:
The invention changes the sintering temperature parameter from conventional high temperatures (1300°C or higher) to lower temperatures (below 1300°C) by modifying the chemical composition of the plugging material. The glass phase forming components enable bonding at these reduced temperatures, significantly lowering energy consumption and production costs while maintaining adequate bonding strength
Solution Approach 2:
The invention uses cost-effective materials such as boron oxide, aluminum oxide, and silicon dioxide as glass phase formers in the plugging material. These relatively inexpensive components enable the use of lower sintering temperatures, reducing overall production costs compared to conventional high-temperature sintering processes
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 excellent thermal shock resistance and reduced production costs by minimizing residual stress and maintaining low thermal expansion coefficient differences, preventing cracking and peeling, and allowing for effective particulate matter capture and regeneration.
Implementation Method 1
where the colloidal oxide is converted to an amorphous oxide matrix at low temperatures, reducing residual stress
Implementation Method 2
differences in thermal expansion coefficients between the sintered ceramic honeycomb body and plugs, leading to cracking and peeling issues under temperature and mechanical stress
Data Source
AI summary
A ceramic honeycomb filter comprising a sintered ceramic honeycomb body having porous partition walls defining flow paths, and plugs formed in predetermined flow paths for removing particulate matter from an exhaust gas passing through the porous partition walls, the sintered ceramic honeycomb body being formed by a cordierite-based ceramic material, at least part of the plugs comprising ceramic particles and an amorphous oxide matrix formed from colloidal oxide.