Honeycomb Seal Material Oxide Particles Thermal Shock
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Solution Overview
Problem
Existing honeycomb structures for exhaust gas purification face challenges in achieving high sealing properties, adhesion strength, and durability due to limitations in seal material performance, particularly in thermal shock resistance and long-term durability.
Innovation Solution
A honeycomb structure utilizing a seal material layer with oxide particles of specific size (0.01 to 100 μm) and an inorganic binder, applied to both the interface between honeycomb units and the outer peripheral surface, enhancing chemical bonding and mechanical properties, including surface roughness adjustment and the use of crystalline oxide particles for improved strength and heat resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional seal materials (carbide or nitride ceramic particles) are used, then thermal conductivity is improved, but sealing properties and adhesion strength deteriorate
Solution Approach 1:
The patent changes the material parameters of the seal material from carbide/nitride ceramics to oxide particles (alumina, zirconia, titania, silica) with specific particle size distributions (0.01-100 μm). This parameter change results in improved sealing properties and adhesion strength while maintaining acceptable thermal conductivity, resolving the contradiction between thermal conductivity and sealing performance.
Solution Approach 2:
The patent uses a composite seal material comprising oxide particles combined with an inorganic binder. This composite structure provides both the thermal stability of oxide ceramics and the adhesive properties needed for strong bonding between honeycomb units, achieving superior sealing properties without sacrificing thermal management capabilities.
2Strength
If seal material layer is applied only at interfaces, then adhesion strength is improved, but sealing of outer peripheral portion deteriorates
Solution Approach 1:
The patent divides the sealing function into two segments: interface sealing (between honeycomb units) and outer peripheral sealing (surrounding the honeycomb block). By applying seal material to both locations, the design ensures comprehensive sealing while maintaining adhesion strength at interfaces through the same material composition.
Solution Approach 2:
The seal material layer serves multiple functions simultaneously: it provides adhesion between honeycomb units at interfaces and creates a sealing barrier at the outer peripheral portion. This multi-functional application of the same material resolves the contradiction between adhesion strength and comprehensive sealing.
3Quantity of substance
If oxide particles with large size range are used, then filling properties are improved, but thermal shock resistance deteriorates
Solution Approach 1:
The patent optimizes the particle size parameter of oxide particles to a specific range of 0.01-100 μm. This controlled parameter change achieves sufficient filling properties for dense seal material while preventing excessive thermal stress concentration that would occur with very large particles, thereby maintaining thermal shock 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 proposed solution significantly enhances sealing properties, adhesion strength, and thermal shock resistance, ensuring long-term durability and effective performance in exhaust gas purification applications, particularly in environments subject to thermal stress.
Implementation Method 1
a seal material layer used for adhering the mutual honeycomb units with each other... the layer of the seal material comprises an inorganic binder and oxide particles
Implementation Method 2
enhancing chemical bonding and mechanical properties, including surface roughness adjustment and the use of crystalline oxide particles for improved strength and heat resistance
Data Source
AI summary
A honeycomb structure is formed by adhering a plurality of honeycomb units provided with cells to each other through a layer of a seal material layer, in which the layer of the seal material comprises an inorganic binder and oxide particles having a particle size of about 0.01 to about 100 μm.