C12A7 Electride Ceramic Composite Thermal Conductivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electron-emitting ceramics, such as C12A7 electrides, suffer from poor thermal conductivity, brittleness, and limited long-term stability due to their poor thermal conductivity, which leads to thermal tensions and cracks, disrupting continuous electron emission.
Innovation Solution
The development of an electron-emitting ceramic composite that consists of at least 70 vol% C12A7 electride ([Ca24Al28O64]4+(4E-)) and 0-30 vol% of specific metals (e.g., Zr, Hf, V, Nb, Ta, Mo, W, Mn, Re, Fe, Ru, Os, Ni, Pd, Pt, Cu, Ag, Au, Cd, In, Sn, Sb, Te, Ti, Pb, Bi) to form a percolation network, enhancing thermal and electrical conductivity while maintaining continuous electron emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If C12A7 electride is used as electron-emitting ceramic, then electron emission capability is improved, but thermal conductivity deteriorates
Solution Approach 1:
The patent applies composite materials by combining C12A7 electride with metallic particles (such as Al, Ti, or their alloys) to create a composite ceramic material. This composite structure allows the material to maintain the excellent electron emission properties of C12A7 while the metallic particles form a percolation network that significantly improves thermal conductivity, thus resolving the contradiction between electron emission capability and thermal conductivity.
2Reliability
If C12A7 electride is used as electron-emitting ceramic, then electron emission capability is improved, but mechanical strength deteriorates
Solution Approach 1:
The patent uses composite materials by incorporating metallic particles into the C12A7 electride matrix. The metallic particles not only improve thermal conductivity but also act as reinforcement that enhances the mechanical strength and fracture toughness of the brittle ceramic, thereby resolving the contradiction between electron emission capability and mechanical strength.
Solution Approach 2:
The patent applies local quality by creating a percolation network of metallic particles distributed throughout the ceramic matrix. This network provides localized pathways for heat conduction and mechanical reinforcement without compromising the overall electron emission properties of the C12A7 electride, thus resolving the contradiction between electron emission capability and mechanical strength.
3Reliability
If C12A7 electride is used as electron-emitting ceramic, then electron emission capability is improved, but long-term stability deteriorates
Solution Approach 1:
The patent applies composite materials by combining C12A7 electride with metallic particles to create a composite structure. The metallic percolation network improves thermal conductivity, which prevents thermal stress accumulation and crack formation during prolonged operation, thereby significantly enhancing the long-term stability and durability of the electron-emitting ceramic while maintaining its electron emission capability.
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 ceramic composite achieves improved thermal conductivity, electrical conductivity, and long-term stability with continuous electron emission, allowing for efficient operation at lower temperatures and reducing the risk of thermal tensions and material degradation.
Implementation Method 1
the metals are present in a proportion between > 0 and 30 vol%, based on the total volume of the ceramic composite, wherein a percolation network of the metals is formed in the electron-emitting ceramic
Implementation Method 2
enhancing thermal and electrical conductivity while maintaining continuous electron emission
Implementation Method 3
By reducing the work function of the electrons from the layer surface in the chamber, lower temperatures are achieved during thermal electron emission
Data Source
AI summary
The invention concerns the field of ceramics and relates to electron-emitting ceramics and how they can be used e.g. as cathode material for electron emissions in space travel systems. The object of the invention is to provide an electron-emitting ceramic, which has improved temperature conductivity alongside simultaneously continuous electron emissions. The object is achieved by an electron-emitting ceramic containing at least > 70 vol.% C12A7-electride and a proportion of Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ru, Os, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, In, Sn, Sb, Te, Tl, Pb or Bi as a metal and/or with Ti, wherein the proportion of metals is between > 0 and < 30 vol. %, and the ceramic has a density of at least 85% of the theoretical density of the ceramic and the ceramic contains 0 to max. 10 vol.% process impurities.