Metastable Intermolecular Composite Deposition Vacuum Interface
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Solution Overview
Problem
Conventional metastable intermolecular composite (MIC) materials suffer from low energy density and burn rate due to the formation of thick interfacial regions during physical vapor deposition, which are contaminated with water vapor, leading to reduced reaction velocity and increased sensitivity to unintentional initiation.
Innovation Solution
Reducing the thickness of the interfacial region to less than 2 nm by performing deposition in a vacuum with a base pressure of <10−8 torr and using a heated metal getter to purify the sputter gas, effectively eliminating water vapor and creating an interface region that is substantially absent, thereby enhancing the reaction velocity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If physical vapor deposition is performed in conventional vacuum chambers, then thin film layers can be deposited, but thick interfacial regions form due to water vapor contamination, reducing reaction velocity
Solution Approach 1:
The patent applies inert atmosphere by performing physical vapor deposition in a highly purified vacuum environment with base pressure <10−8 torr and using heated metal getters to remove water vapor. This creates an inert interface region free of water vapor contamination, preventing the formation of thick reacted layers and enabling sharp interfaces between metal and metal oxide layers.
Solution Approach 2:
The patent extracts water vapor from the deposition environment using heated metal getters and high vacuum techniques. By removing water vapor from the system, the harmful interfacial reactions are eliminated, allowing for the formation of thin or non-existent interfacial regions that would otherwise form due to moisture contamination.
2Speed
If thick interfacial regions are formed during deposition, then some stability is achieved, but reaction velocity decreases and energy density is reduced
Solution Approach 1:
By creating an inert deposition environment with base pressure <10−8 torr and using heated metal getters, the patent eliminates water vapor that would otherwise form thick interfacial layers. This results in sharp interfaces with minimal reacted zones, enabling high reaction velocities while maintaining stability through controlled interface chemistry.
3Productivity
If conventional vacuum deposition is used, then deposition can be performed, but residual water vapor forms reacted layers at interfaces, reducing burn rate
Solution Approach 1:
The patent uses highly purified vacuum conditions with base pressure <10−8 torr and heated metal getters to create an inert environment that prevents water vapor from reacting with metal surfaces. This eliminates the formation of reacted layers at interfaces, maintaining maximum burn rates by preserving reactive metal surfaces.
Solution Approach 2:
The patent extracts water vapor from the deposition chamber using heated metal getters and high vacuum techniques. This removal of water vapor prevents the formation of reacted layers, ensuring that metal and metal oxide layers maintain sharp interfaces with minimal reacted material, thereby preserving high burn rates.
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 reaction velocity of MICs is increased by a factor of five or more, achieving higher energy density and reduced sensitivity to unintentional initiations, resulting in improved performance for energetic materials.
Implementation Method 1
using a heated metal getter to purify the sputter gas, effectively eliminating water vapor
Implementation Method 2
performing deposition in a vacuum with a base pressure of <10−8 torr
Implementation Method 3
These two materials are selected such that upon initiation they are capable of a chemical reaction with one another to form a different material or materials (products), and release heat
Data Source
AI summary
A method for forming a metastable intermolecular composite (MIC) includes providing a vacuum level of <10−8 torr base pressure in a deposition chamber. A first layer of a first material of a metal that is reactive with water vapor is deposited, followed by depositing a second layer of a second material of a metal oxide on the first layer. The first and second material are capable of an exothermic chemical reaction to form at least one product, and the first and second layer are in sufficiently close physical proximity so that upon initiation of the exothermic reaction the reaction develops into a self initiating chemical reaction. An interfacial region averaging <1 nm thick is formed between the first layer and second layer from a reaction of the first material with water vapor. In one embodiment, the first material is Al and the second material is CuOx.