SMA Wire Oxide Coating for Composite Impact Resistance

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Solution Overview

Problem

Current composite materials with high strength-to-weight ratio and impact resistance, incorporating shape memory alloy (SMA) wires and fibers, face challenges in manufacturing efficiency and achieving optimal impact performance, inter-laminar strength, and complex structure formation.

Innovation Solution

A composite material comprising a polymer matrix with SMA wires and reinforcing fibers, where SMA wires have a dark oxide coating of at least 2000 Angstroms thickness, arranged in various configurations such as unidirectional, 2D, or 3D preforms, providing improved impact performance, inter-laminar strength, and the ability to form complex structures efficiently.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If SMA wires with thick oxide coating are used to enhance impact resistance, then impact performance is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveimpact resistanceVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The oxide coating is applied to SMA wires before they are embedded in the polymer matrix, allowing the coating to be formed in advance as part of the wire preparation process. This preliminary action integrates the coating step into the manufacturing sequence rather than requiring post-processing, thereby improving impact resistance while controlling manufacturing complexity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent specifies controlling the oxide coating thickness to be within 1-10 micrometers, optimizing this parameter to achieve sufficient impact resistance without excessive coating that would complicate manufacturing. By defining a specific parameter range, the invention balances performance improvement with manufacturability

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If complex 3D structures are formed using woven preforms, then structural capability is improved, but manufacturing efficiency decreases

Engineering Contradiction:
Improvestructural capabilityVSAvoidmanufacturing efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The complex 3D structure is created by assembling multiple woven preform layers in a stacked configuration, with each layer representing a segment of the overall structure. This segmentation allows each layer to be manufactured using efficient woven preform techniques while the stacking process creates the final complex 3D geometry, balancing structural capability with manufacturing efficiency

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention embeds SMA wires within the polymer matrix of woven preform layers, creating a nested structure where the wires are contained within the composite material. This nesting approach allows complex 3D structures to be formed while maintaining the manufacturing efficiency of woven preform processes

Inventive Principle:
Principle #7Nested doll (Nesting)

3Strength

If multiple plys are used to improve inter-laminar strength, then strength is improved, but processing complexity increases

Engineering Contradiction:
Improveinter-laminar shear strengthVSAvoidprocessing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

Multiple preform layers with SMA wires are combined and stacked to form a multi-ply composite structure. The weaving process integrates the layers into a unified preform that can be processed together, achieving improved inter-laminar strength while managing processing complexity through the merging of layers during the preform creation stage

Inventive Principle:
Principle #5Merging (Combining)

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 dark oxide coating enhances the composite's impact resistance and inter-laminar shear strength, allowing for the creation of complex 3D structures with improved manufacturing efficiency and multifunctional properties.

Implementation Method 1

One or more of the SMA wires in the composite materials and preforms described herein have a dark oxide coating

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentEP3843980B1product
Publication Date: 2023.07.12 QINETIQ LTD
  • EP3843980B1 patent drawingFigure 1a~1b
  • EP3843980B1 patent drawingFigure 1c
  • EP3843980B1 patent drawingFigure 2

AI summary

A preform comprising reinforcing fibres and shape memory alloy (SMA) wires, a composite material comprising a polymer matrix with a preform embedded therein, articles comprising a composite material, methods of making preforms, composite materials and articles.