Composite Part Bonding via Surface Features

Solution Overview

Problem

Composite parts made from different materials face challenges in assembly and bonding due to differing material properties, such as thermal expansion coefficients, leading to cracks, gaps, and weakened bonds during hot forming techniques.

Innovation Solution

Incorporating a titanium-based internal insert component with surface features and an aluminum-based external part component, where the surface features increase the bonding area and create a mechanical interlock, and optionally using a shell or coating layer to enhance metallurgical bonding, thereby improving the bond strength between the materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If different materials are used to create composite parts, then a blend of material properties (strength, light weight) is achieved, but cracks, dislocations, and gaps occur between materials due to different coefficients of thermal expansion

Engineering Contradiction:

Improveblend of material propertiesVSAvoidbond strength

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The insert component is pre-formed with surface features (protrusions, recesses, roughness) before being placed in the mold cavity. These surface features are prepared in advance to create mechanical interlocking with the molten material, preventing gaps and dislocations that would otherwise occur due to thermal expansion differences during casting.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Surface features are applied locally to specific regions of the insert component where bonding is critical. The protrusions and recesses create localized mechanical interlocks at the interface between the insert and the cast material, providing enhanced bond strength precisely where needed while maintaining the overall lightweight composite structure.

Inventive Principle:

Principle #3Local quality

2Ease of manufacture

If hot forming techniques are used to assemble composite parts, then materials are joined together, but cracks and gaps form between materials due to different rates of thermal expansion

Engineering Contradiction:

Improveassembly processVSAvoidbond quality

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The insert component is pre-formed with surface features (protrusions, recesses, roughness) before being placed in the mold cavity. These surface features are prepared in advance to create mechanical interlocking with the molten material, preventing gaps and dislocations that would otherwise occur due to thermal expansion differences during casting.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The surface topology of the insert is modified by introducing protrusions and recesses that change the physical parameters of the bonding interface. This mechanical interlocking structure compensates for the thermal expansion parameter differences between materials during the hot forming process, maintaining bond quality despite temperature variations.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If a smooth surface is used on the internal insert component, then manufacturing is simpler, but bonding area is reduced and mechanical interlock is weakened

Engineering Contradiction:

Improvesurface preparationVSAvoidbond strength

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

Surface features are applied locally to specific regions of the insert component where bonding is critical. The protrusions and recesses create localized mechanical interlocks at the interface between the insert and the cast material, providing enhanced bond strength precisely where needed while maintaining the overall lightweight composite structure.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The surface features include asymmetric protrusions and recesses that create interlocking geometry. This asymmetric surface topology provides mechanical anchoring that prevents gaps and dislocations, significantly enhancing bond strength compared to a symmetric smooth surface while remaining manufacturable through standard processes.

Inventive Principle:

Principle #4Asymmetry

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 results in a stronger composite part with improved mechanical bond strength, mitigating losses in bond strength from gaps and enhancing the overall strength of the composite part, particularly in applications requiring lightweight yet high-strength materials.

Implementation Method 1

the surface features increase the bonding area and create a mechanical interlock

Methodology Applied

Scientific EffectMechanical interlock:

Implementation Method 2

casting a molten material around the internal insert component; solidifying the molten material to form the external part component

Methodology Applied

Scientific EffectSolidification: Freezing

Data Source

PatentUS11338359B2Composite part with external part cast around internal insert and method for producing the same

Publication Date: 2022.05.24 ALUDYNE NORTH AMERICA LLC

AI summary

Composite parts (100) and methods of making the same are disclosed. A composite part may include an internal insert component (124) made of a first material. The internal insert component may be provided with surface features such as mechanical surface features or material surface features, on at least a portion of its surface. The composite part may further include an external part component (136) that is cast around at least a portion of the internal insert component, and is made of a second material different from the first material. The surface features of the internal insert component may help establish a bond within the composite part between the internal insert component and the external part component.