Laser Sintering Equipment Molten Droplet Collection Element

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Solution Overview

Problem

The existing selective melting of powder processes using laser or electron beams face issues with molten metal droplets forming large solid particles that cannot be remelted, resulting in core defects and weakened mechanical properties in the manufactured parts, which are difficult to mitigate without costly diffusion heat treatments.

Innovation Solution

An installation with a collection element, such as a disc-shaped plate with a flared opening and annular concavity, is used to catch and solidify molten droplets, preventing them from falling onto the part being manufactured, and the collection element is mounted on a frame that moves in two perpendicular directions to ensure all projections are collected.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a laser beam or electron beam is used to melt successive layers of powder, then parts with small wall thicknesses and complex geometries can be produced, but drops of molten metal are thrown out of the liquid bath to form large solid particles that create defects in the part core

Engineering Contradiction:
Improveability to produce parts with small wall thicknesses and complex geometriesVSAvoidmolten metal droplets forming large solid particles that create defects
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The harmful molten metal droplets are extracted from the system by introducing a collection element (suction device) that actively removes projections before they can fall onto the part. The suction device extracts droplets from the liquid bath zone, preventing them from becoming defects in the final part.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A collection element acts as an intermediary between the liquid bath and the powder bed. This intermediary component (with suction capabilities) intercepts molten droplets in flight, providing a protective barrier that prevents harmful projections from reaching the part while allowing the laser/electron beam to continue melting powder.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If diffusion heat treatment is applied to limit defects from projections, then mechanical characteristics are improved, but the process becomes long and costly

Engineering Contradiction:
Improvemechanical characteristics of the partVSAvoidduration of diffusion heat treatment
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The harmful projections are eliminated in advance during the manufacturing process itself, before the part is completed. By using the collection element to remove droplets during melting operations, the part is produced with fewer defects from the start, eliminating or reducing the need for subsequent time-consuming diffusion heat treatment to correct defects.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The collection element converts the harmful effect of molten droplet projection into a beneficial outcome by capturing these droplets and preventing them from becoming defects. The suction device transforms what would be a harmful process (droplet ejection) into a controlled process where droplets are captured and removed, eliminating the need for corrective heat treatment.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Object-generated harmful factors

If a collection element is introduced to suck up splashes of molten powder, then projections are prevented from falling on the part, but the device complexity increases

Engineering Contradiction:
Improveprojections of molten powder falling on the partVSAvoidcomplexity of the manufacturing installation
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The collection element is designed to perform multiple functions: it collects and removes molten droplets, maintains appropriate atmospheric conditions in the working zone, and can be integrated with the existing laser or electron beam system. This multi-functionality justifies the added complexity by providing comprehensive protection against projections while supporting the primary manufacturing process.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 effectively prevents molten droplets from integrating into the final part, enhancing mechanical properties by eliminating core defects and reducing the need for lengthy and costly heat treatments.

Implementation Method 1

manufacturing a part by melting successive layers of powder by means of a laser beam or an electron beam

Methodology Applied
Scientific EffectLaser beam energy: Laser

Implementation Method 2

manufacturing a part by melting successive layers of powder by means of a laser beam or an electron beam

Methodology Applied
Scientific EffectElectron beam energy: Electron Beam

Implementation Method 3

The energy provided by this beam causes local melting of the powder which, on solidifying, forms a first layer of the metal part

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 4

the splashes of molten powder cling to the collection element after solidification

Methodology Applied
Scientific EffectSolidification: Freezing

Implementation Method 5

The drops or splashes of molten powder therefore pass entirely through the opening to fall back and solidify on the upper face of the collection plate

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2709790B1Laser selective sintering equipment for manufacturing parts
Publication Date: 2019.08.14 SAFRAN AIRCRAFT ENGINES SAS
  • EP2709790B1 patent drawingFigure 1~2
  • EP2709790B1 patent drawingFigure 3~6

AI summary

The invention relates to a tool for manufacturing a part by selectively melting a powder, comprising means for producing a beam, for example a laser beam or an electron beam, and means for moving the point of impact of the beam over a layer of powder. The tool furthermore comprises an element for collecting molten powder spray (24) produced when the powder is locally melted by the beam (11), comprising an aperture (15) allowing the beam (11) to pass, and means designed to move said collecting element (14) jointly with the beam (11), above the layer of powder.