Metal Powder Diffusion Barrier for Pore-Reduced Additive Manufacturing

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Solution Overview

Problem

Existing additive manufacturing processes face issues with uncontrolled sintering of metal powders at elevated temperatures, leading to surface pores and the need for additional finishing processes.

Innovation Solution

A manufacturing process using a mixture of metal particles and a diffusion barrier substance, where the latter inhibits uncontrolled fusing by forming a selective diffusion barrier between metal particles, preventing them from diffusing and sintering uncontrollably, even at temperatures below their melting point.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If powder material is heated to elevated temperature for solidification, then material fusion and part formation is improved, but uncontrolled sintering occurs creating surface pores

Engineering Contradiction:
Improvepart formation qualityVSAvoidsurface pores from uncontrolled sintering
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

A coating material is applied to the powder particles as an intermediary substance. This coating acts as a diffusion barrier that prevents direct contact and uncontrolled sintering between metal powder particles while allowing the energy beam to pass through and melt the material for controlled fusion and part formation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention uses a composite material system consisting of metal powder particles coated with a diffusion barrier material. This composite structure combines the desirable properties of metal powder (fusibility, strength) with the protective properties of the coating material (diffusion barrier, pore prevention) to achieve controlled solidification without uncontrolled sintering.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If powder material is heated to elevated temperature for solidification, then material fusion is improved, but additional post-processing finishing is required

Engineering Contradiction:
Improvematerial fusion qualityVSAvoidpost additive manufacturing finishing time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The coating material serves as a protective intermediary that prevents surface defects during the heating and solidification process. By preventing uncontrolled sintering and pore formation at the source, the coating eliminates the need for subsequent post-processing finishing operations, thereby reducing manufacturing time.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The coating is applied to the powder particles before the additive manufacturing process begins. This preliminary action of coating the particles prevents surface defects from forming during solidification, eliminating the need for later corrective finishing operations and reducing overall process time.

Inventive Principle:
Principle #10Preliminary action

3Object-affected harmful factors

If diffusion barrier coating is applied to powder particles, then uncontrolled sintering is prevented, but coating material must be removed after manufacturing

Engineering Contradiction:
Improveuncontrolled sintering preventionVSAvoidcoating removal process
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The coating material is designed to be temporarily present during manufacturing to prevent defects, then systematically removed after the part is formed. The coating serves its protective function during the critical solidification phase and is then discarded through removal processes, allowing the part to be recovered in its final form without permanent coating interference.

Inventive Principle:
Principle #34Discarding and recovering

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 approach reduces uncontrolled sintering, minimizing surface pores and potentially shortening or eliminating the need for post-manufacturing finishing processes, while maintaining the chemical properties of the metal parts.

Implementation Method 1

the second substance 14 is operable to substantially inhibit or significantly reduce uncontrolled fusing (e.g., sintering) of some or all of the first substance particles 16 together before, for example, application of a solidification energy beam thereto. More particularly, the second substance 14 may form a selective diffusion barrier between some or all of the first substance particles 16

Methodology Applied
Scientific EffectDiffusion barrier: Diffusion Barrier

Data Source

PatentEP3096910B1Additive manufacturing an object from material with a selective diffusion barrier
Publication Date: 2021.07.07 RTX CORP
  • EP3096910B1 patent drawingFigure 1
  • EP3096910B1 patent drawingFigure 2
  • EP3096910B1 patent drawingFigure 3

AI summary

A manufacturing process is provided in which material is supported within a chamber. This material includes a plurality of discrete metal particles and ceramic disposed between at least some of the metal particles. At least a portion of the material is solidified together using an additive manufacturing system to form an object.