Stationary-Shoulder Friction Stir Deposition for Heat Localization

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Solution Overview

Problem

Existing additive manufacturing by friction stir deposition processes lack sufficient control over heat localization, leading to inconsistent material deposits in terms of size, mechanical properties, and surface finish, as well as potential deformation in the substrate or built-up form.

Innovation Solution

The implementation of an additive friction stir deposition machine with a stationary tool and a rotatable guide tube, where the guide tube contains spiral grooves to direct feedstock material inwardly and passages for cooling fluid circulation to maintain stable temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If both the tool and feedstock rod rotate with respect to the substrate, then the feedstock can be added to the substrate to create patterns and build layers, but heat control becomes insufficient leading to inconsistent material deposits and tooling problems

Engineering Contradiction:

Improvematerial deposition capabilityVSAvoidheat localization control

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The patent inverts the conventional rotation scheme by making the feedstock rod stationary while rotating only the guide tube. This reversal of roles resolves the heat control issue by eliminating the source of uncontrolled heat generation (rotating feedstock against substrate) while preserving the material deposition capability through the rotation of the guide tube that delivers the feedstock to the stationary tool's deposition point.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The tool is segmented into two independent rotational components: a stationary feedstock rod and a rotatable guide tube. This segmentation allows independent control of material delivery (via guide tube rotation) and deposition (via stationary tool positioning), thereby achieving precise heat localization while maintaining productivity.

Inventive Principle:

Principle #1Segmentation

2Productivity

If the tool rotates against the upper surface of the plasticized layer, then material can be deposited, but an inconsistent finish is created in the final weld

Engineering Contradiction:

Improvematerial deposition rateVSAvoidsurface finish consistency

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

Instead of rotating the tool against the plasticized layer surface, the patent makes the feedstock rod stationary and rotates the guide tube. This inversion ensures that the stationary tool consistently processes the material at a fixed position, eliminating the inconsistent surface finish caused by rotational variation while maintaining deposition throughput.

Inventive Principle:

Principle #13The other way round (Inversion)

3Device complexity

If heat is not controlled locally, then the deposition process can proceed without complex cooling, but material deposits vary in size and mechanical properties and substrate deformation occurs

Engineering Contradiction:

Improvecooling system complexityVSAvoiddeposit consistency and substrate dimensional stability

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

By inverting the rotation scheme to have a stationary feedstock rod and rotatable guide tube, the patent inherently localizes heat generation to a fixed position at the tool-substrate interface. This eliminates the need for complex active cooling systems while ensuring consistent deposit properties and preventing substrate deformation, as the heat input is controlled by the stationary geometry rather than rotational motion.

Inventive Principle:

Principle #13The other way round (Inversion)

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

This solution enables precise control over heat localization, resulting in consistent material deposits with improved mechanical properties and surface finish, while minimizing deformation and tooling issues.

Implementation Method 1

Additive manufacturing by friction stir deposition is a known process that uses friction between a consumable feedstock material and a non-consumable substrate material

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

The stationary tool may also include passages for the flow of cooling fluid to circulate through it

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentUS12290873B2Friction stir additive method and machine

Publication Date: 2025.05.06 BOND TECH INC

AI summary

An additive friction stir deposition machine and the method of using it. The friction stir deposition machine has a stationary tool with a fixed shoulder and an opening. The fixed shoulder is fixed from rotation with respect to a substate onto which feedstock material is deposited to build a layer. A guide tube holds the feedstock material and is rotatable within the stationary tool. The opening in the stationary shoulder circumscribes the open end of the guide tube. The feedstock material is co-rotatable with the guide tube and rotating the guide tube rotates with the feedstock.