Phase Gradient Nanocomposite Optical Window for Strength and Transparency

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Solution Overview

Problem

Optical windows for aircraft and high-speed missiles face challenges in balancing flexure strength, impact durability, and optical transparency, with nanocomposite windows suffering from increased optical absorption and scattering due to added phases, and existing coatings being insufficiently durable.

Innovation Solution

A phase gradient nanocomposite window design featuring a nanocomposite optical ceramic outer layer with a distribution gradient of formulations, combined with a single-phase inner layer and an electromagnetic interference treatment layer, utilizing centrifugal force to concentrate hardening agents at the surface for enhanced mechanical strength and reduced optical absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If nanocomposite materials with multiple phases are used to enhance mechanical strength, then flexure strength and impact durability are improved, but optical transparency deteriorates due to increased absorption and scattering

Engineering Contradiction:
Improveflexure strengthVSAvoidoptical transparency
Core Design Contradiction:
StrengthVSIllumination intensity

Solution Approach 1:

The patent applies local quality by creating a spatially varying composition within the nanocomposite material. Different regions of the material have different phase distributions - with the second phase concentrated in specific areas to provide mechanical strength where needed, while other regions maintain high optical transparency. This is achieved through controlled processing that creates a non-uniform microstructure, allowing the material to simultaneously exhibit both enhanced strength and maintained transparency in different locations.

Inventive Principle:
Principle #3Local quality

2Strength

If nanocomposite materials with multiple phases are used to enhance mechanical strength, then impact durability is improved, but optical transparency deteriorates due to increased absorption and scattering

Engineering Contradiction:
Improveimpact durabilityVSAvoidoptical transparency
Core Design Contradiction:
StrengthVSIllumination intensity

Solution Approach 1:

The patent applies local quality by creating a spatially varying composition within the nanocomposite material. Different regions of the material have different phase distributions - with the second phase concentrated in specific areas to provide mechanical strength where needed, while other regions maintain high optical transparency. This is achieved through controlled processing that creates a non-uniform microstructure, allowing the material to simultaneously exhibit both enhanced strength and maintained transparency in different locations.

Inventive Principle:
Principle #3Local quality

3Reliability

If conventional coatings are applied to windows to provide protection, then durability is improved, but the coatings are insufficiently durable in harsh environments

Engineering Contradiction:
ImprovedurabilityVSAvoidcoating longevity
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent applies composite materials by integrating the protective function directly into the bulk nanocomposite structure rather than relying on separate surface coatings. The multi-phase nanocomposite creates an inherently durable material where the second phase provides mechanical reinforcement and environmental resistance throughout the material volume. This bulk composite approach eliminates the weakness of thin surface coatings that can flake or degrade, providing sustained protection in harsh environments.

Inventive Principle:
Principle #40Composite materials

4Productivity

If near net shape sintering is used to produce windows, then manufacturing efficiency is improved and material waste is reduced, but optical absorption and scattering increase due to added hardening agents

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidoptical absorption
Core Design Contradiction:
ProductivityVSIllumination intensity

Solution Approach 1:

The patent applies local quality by creating a spatially varying composition within the nanocomposite material. Different regions of the material have different phase distributions - with the second phase concentrated in specific areas to provide mechanical strength where needed, while other regions maintain high optical transparency. This is achieved through controlled processing that creates a non-uniform microstructure, allowing the material to simultaneously exhibit both enhanced strength and maintained transparency in different locations.

Inventive Principle:
Principle #3Local quality

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 durable optical windows with improved mechanical durability and optical transparency, allowing for enhanced performance in harsh environments without sacrificing transparency, and enabling new hardening agents to be introduced without adverse effects on optical clarity.

Implementation Method 1

utilizing centrifugal force to concentrate hardening agents at the surface for enhanced mechanical strength and reduced optical absorption

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3523599B1Phase gradient nanocomposite window fabrication and method of fabricating durable optical windows
Publication Date: 2024.02.14 RAYTHEON CO
  • EP3523599B1 patent drawingFigure 1~4
  • EP3523599B1 patent drawingFigure 5
  • EP3523599B1 patent drawingFigure 6~7

AI summary

An optical window is provided and includes a core layer, a cladding layer and an electromagnetic interference (EMI) layer interposed between the core and cladding layers.