Sacrificial Coating for Additive Manufacturing Powder Safety

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current additive manufacturing techniques face limitations due to powders being flammable, reactive to oxygen and moisture, or requiring high energy for melting/sintering, which complicates handling and processing, leading to potential contamination and reduced throughput.

Innovation Solution

A method involving particles coated with a sacrificial material that differs in composition from the article material, allowing for separation during fusing, reducing flammability, contaminant affinity, and energy requirements, using either discontinuous or continuous coatings applied via line-of-sight or non-line-of-sight techniques.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If flammable powders like titanium are used in additive manufacturing, then the article material properties are achieved, but safety risks and handling complexity increase due to flammability

Engineering Contradiction:

ImprovesafetyVSAvoidhandling complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

A sacrificial coating material is applied as an intermediary layer between the flammable article material and the ambient environment. This coating acts as a protective barrier during handling and storage, preventing direct exposure of flammable powders to oxygen and eliminating the need for specialized explosion or fire suppression precautions.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The sacrificial coating creates an inert protective environment around each particle, effectively isolating flammable article materials from oxygen exposure during handling. This eliminates the need for complex inert atmosphere handling systems while maintaining safety.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

2Reliability

If reactive powders like aluminum are used in additive manufacturing, then the desired material properties are achieved, but contamination risks increase due to affinity for oxygen and moisture

Engineering Contradiction:

Improvematerial purityVSAvoidspecialized handling requirements

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The sacrificial coating serves as an intermediary barrier that prevents direct contact between reactive article materials and contaminants in the ambient environment. This simple coating approach eliminates the need for complex specialized handling systems while ensuring material purity.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If highly reflective powders like oxygen-free high conductivity copper are used in additive manufacturing, then the desired material properties are achieved, but energy efficiency decreases due to significant energy reflection during melting or sintering

Engineering Contradiction:

Improvematerial propertiesVSAvoidenergy efficiency

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The sacrificial coating changes the surface optical parameters of the article material particles. By applying a coating with different optical properties than the highly reflective copper, the surface reflectance is modified to improve energy absorption during melting or sintering, thereby increasing energy efficiency while maintaining the underlying material properties.

Inventive Principle:

Principle #35Parameter changes

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 sacrificial coating reduces the risk of ignition, prevents contaminant incorporation, and lowers the energy needed to fuse the article material, enhancing the additive manufacturing process by improving safety, reducing specialized handling needs, and increasing efficiency.

Implementation Method 1

fusing the article material can include heating the sacrificial material and conducting heat from the sacrificial material into the article material

Methodology Applied

Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

separating the sacrificial material from the article material can include floating the sacrificial material in the article material during melting of the powder and/or article material

Methodology Applied

Scientific EffectMelting: Melting

Implementation Method 3

separating the sacrificial material from the article material can include floating the sacrificial material in the article material during melting of the powder and/or article material

Methodology Applied

Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 4

A coating formed from a sacrificial coating is first deposited over the particle surface

Methodology Applied

Scientific EffectDeposition: Deposition (physical)

Data Source

PatentUS10626503B2Particulates and methods of making particulates

Publication Date: 2020.04.21 HAMILTON SUNDSTRAND CORP

AI summary

A method of making an article using an additive manufacturing technique includes depositing a powder. The powder includes particles formed from an article material and having particle surfaces. A coating formed from a sacrificial coating is deposited over the particle surface. The sacrificial material has a composition that is different from the composition of the article material and is separated from the article material during fusing of the article material into a layer of an additively manufactured article.