Graphite-Silicon Composite Intermediate Layer Thermal Shock
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Solution Overview
Problem
Existing methods for forming graphite-silicon composites for radioactive-ray optical elements and heat-countermeasure members are costly, require multiple steps, and suffer from reduced X-ray intensity, increased noise, and insufficient thermal shock resistance due to the use of polycrystal-silicon or silicon-carbide films and doping with boron.
Innovation Solution
A graphite-silicon composite with an intermediate layer containing oxygen, carbon, and silicon, produced by layering graphite and silicon and heating them under controlled pressure and oxygen concentration, maintaining high crystallinity and diffraction performance while securing strength against thermal shock.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polycrystal-silicon or silicon-carbide films are preliminarily formed on the substrate by vacuum-based devices, then the joining of carbon substrate and silicon substrate can be achieved, but the production process becomes complex and costly
Solution Approach 1:
The invention extracts and removes the complex vacuum-based film formation steps and doping processes from the production method. Instead of using polycrystal-silicon or silicon-carbide films formed by vacuum devices, the patent directly joins graphite and silicon substrates through a simplified heating process, eliminating the need for vacuum equipment and complex preliminary film formation steps.
Solution Approach 2:
The invention enables the graphite and silicon substrates to join themselves through direct heating at 500-2000°C without requiring external vacuum-based film formation equipment. The substrates spontaneously form the desired composite structure through self-diffusion and bonding when heated, eliminating the need for complex external processing equipment.
2Adaptability or versatility
If doping is performed to adapt to different substrate types, then the composite can be optimized for specific applications, but the number of production steps increases and cost increases
Solution Approach 1:
The invention extracts and removes the doping step from the production process. By eliminating boron doping and other chemical modification steps, the patent reduces the number of production steps while maintaining the ability to produce composites suitable for various applications including radioactive-ray optical elements and heat-countermeasure members.
Solution Approach 2:
The invention achieves substrate optimization through parameter changes in the heating process (temperature range of 500-2000°C) rather than through doping. By adjusting heating temperature and atmosphere conditions, the composite can be optimized for different applications without requiring additional doping steps, thus maintaining productivity.
3Reliability
If boron doping is used in the composite, then the composite can be formed successfully, but X-ray diffraction intensity decreases and noise increases
Solution Approach 1:
The invention extracts and removes boron doping from the production process. By eliminating the doping step, the patent prevents the introduction of boron impurities that would otherwise degrade X-ray diffraction quality. The composite is formed successfully through direct heating without requiring boron doping, thus maintaining high X-ray diffraction intensity and low noise.
4Reliability
If a compound layer of silicon and carbon is formed at the joining interface, then the graphite and silicon substrates can be joined, but the elastic modulus increases making the composite vulnerable to thermal shock
Solution Approach 1:
The invention controls the heating temperature parameter (500-2000°C) and atmosphere conditions to optimize the joining process. By carefully controlling these parameters, the patent achieves strong joining between graphite and silicon substrates while minimizing the formation of excessive compound layers that would increase elastic modulus and reduce thermal shock resistance. The direct heating method allows for controlled diffusion bonding without creating harmful interface compounds.
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 composite achieves excellent X-ray diffraction performance, sufficient thermal shock resistance, and maintains high heat conductivity, making it suitable for radioactive-ray optical elements and heat-countermeasure applications.
Implementation Method 1
the applied pressure is adjusted to 24.5 MPa or higher
Implementation Method 2
the heating temperature is adjusted to 1260° C. or higher
Implementation Method 3
an intermediate layer that is located between the graphite and the silicon, wherein the intermediate layer includes oxygen, carbon and silicon
Data Source
AI summary
A graphite-silicon composite, including: graphite; silicon; and an intermediate layer that is located between the graphite and the silicon, wherein the intermediate layer includes oxygen, carbon and silicon. Furthermore, provided is a method for producing a graphite-silicon composite, including: layering graphite and silicon; and heating the layered graphite and silicon while applying pressure to them, wherein, during heating the layered graphite and silicon while applying pressure to them, an oxygen concentration in the atmosphere is adjusted to 0.2 vol %, the applied pressure is adjusted to 24.5 MPa or higher, and the heating temperature is adjusted to 1260° C. or higher.