Multi-Electron Beam Powder Preheating to Prevent 3D Printing Discharge

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Solution Overview

Problem

The use of electron beams for sintering powders in 3D object production can lead to electrical discharges due to charge distribution, causing structural damage and inefficiencies, especially when multiple beams are involved, as existing methods do not adequately address charge density issues.

Innovation Solution

A method and device that pre-heat the powdery material using multiple electron beams with a controlled security distance and synchronization to prevent charge accumulation, ensuring homogeneous heating and avoiding electrical discharges, allowing for efficient fusion of the material without additional heating equipment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple electron beams are used to increase productivity, then production efficiency is improved, but charge distribution density increases causing electrical discharges that destroy powder layer structure

Engineering Contradiction:

Improveproduction efficiencyVSAvoidelectrical discharge

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The build area is divided into multiple regions, each scanned by a separate electron beam. The beam paths are segmented into discrete scan lines with controlled spacing, ensuring that charge accumulation is localized and managed within specific zones rather than affecting the entire powder layer uniformly.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The electron beams perform preliminary scanning of the powder layer before actual sintering begins. This preliminary action distributes charge more evenly across the powder particles, preventing critical charge density buildup that would lead to electrical discharges during the main sintering process.

Inventive Principle:

Principle #10Preliminary action

2Use of energy by moving object

If electron beam power is increased to improve heating efficiency, then energy utilization is improved, but charge density increases leading to electrical discharges

Engineering Contradiction:

Improveheating efficiencyVSAvoidelectrical discharge

Core Design Contradiction:

Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The electron beam operates in periodic cycles, alternating between high-power sintering passes and lower-power scanning passes. During scanning passes, the beam redistributes charge without delivering excessive energy. This periodic modulation allows efficient heating over time while preventing charge density from reaching discharge thresholds during any single pass.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The beam parameters (power, scanning speed, pulse duration) are dynamically adjusted during the process. When charge density approaches critical levels, the system reduces beam power or increases scanning speed to prevent discharge. This adaptive parameter control maintains heating efficiency while avoiding electrical discharges.

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

This approach ensures homogeneous pre-heating, prevents electrical discharges, and increases efficiency in 3D object production by maintaining controlled temperature gradients and charge distribution, enabling the use of multiple electron beams effectively.

Implementation Method 1

irradiating it with at least two electron beams emanating from at least two electron beam sources

Methodology Applied

Scientific EffectElectron beam heating: Electron Beam

Implementation Method 2

The powder sinters or melts and solidifies as the beam moves over the working area

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 3

the powder sinters or melts and solidifies as the beam moves over the working area

Methodology Applied

Scientific EffectMelting: Melting

Data Source

PatentUS20220176458A1Method and device for producing three-dimensional objects

Publication Date: 2022.06.09 ARCAM AB

AI summary

A method for producing three-dimensional objects layer by layer using a powdery material which can be solidified by irradiating it with at least two electron beams, said method comprises a pre-heating step, wherein the pre-heating step comprises the sub-step of scanning a pre-heating powder layer area (100) by scanning a first electron beam in a first region (I) and by scanning a second electron beam in a second region (II) distributed over the pre-heating powder layer area (100), wherein consecutively scanned paths are separated by, at least, a security distance (ΔY), said sub-step further comprising the step of synchronising the preheating of said first and second electron beams when simultaneously preheating said powder material within said first and second regions respectively, so that said first and second electron beams are always separated to each other with at least a minimum security distance (ΔX).