Preheated Wire Additive Manufacturing Under Vacuum for Precise Metal Builds

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Solution Overview

Problem

Existing additive manufacturing methods for three-dimensional metallic components face challenges such as high energy input leading to deep melting, material inefficiency, and excessive residual powder due to the use of powder layers and high heat input during the layering process, especially in components with complex structures and cavities.

Innovation Solution

The method employs preheating the metallic wire using resistance heating or inductive heating within vacuum conditions before it reaches the processing point, reducing the energy required from the laser beam for fusion, allowing for precise control and minimizing heat input into the workpiece, thereby reducing material waste and improving layer precision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If powder layers are applied and fused layer by layer, then complex three-dimensional structures can be produced, but large quantities of residual powder are not fused to the component

Engineering Contradiction:
Improveability to produce complex three-dimensional structuresVSAvoidresidual powder waste
Core Design Contradiction:
Adaptability or versatilityVSLoss of substance

Solution Approach 1:

The patent changes the material form parameter from powder to wire, and changes the heating method parameter from direct laser heating of powder to electrical preheating of wire. This allows precise material delivery through wire feeding while minimizing excess material, directly addressing the residual powder waste problem while maintaining the ability to create complex structures

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical powder spreading and layering system with an electrical wire feeding and heating system. Instead of mechanically applying and fusing powder layers, the system uses electrical resistance heating or inductive heating to preheat wire before fusion, eliminating the powder application step that generates residual waste

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If high energy is supplied by laser or electron beam to apply powder layers, then material deposition is achieved, but undesirably deep melting of already produced material layers occurs

Engineering Contradiction:
Improvematerial deposition rateVSAvoiddepth of melting penetration
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary heating action by electrically preheating the wire before it reaches the processing point. This preliminary action raises the wire temperature close to its melting point in advance, so that when the laser or electron beam acts on the wire, significantly less energy is needed to complete the fusion, thereby preventing deep melting of previously deposited layers while maintaining deposition productivity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the heating parameter from direct high-energy laser/electron beam heating of the workpiece to electrical preheating of the wire feedstock. This parameter change separates the preheating function from the fusion function, allowing precise control of total heat input and preventing excessive penetration into already produced layers

Inventive Principle:
Principle #35Parameter changes

3Temperature

If wire is preheated using electron beam, then wire heating is achieved, but the same electron beam must also provide melting energy at the processing point

Engineering Contradiction:
Improvewire preheating temperatureVSAvoidelectron beam system requirements
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent segments the heating function into two separate systems: an electrical preheating system (resistance heating or inductive heating) for heating the wire before it reaches the processing point, and a laser or electron beam system for providing the remaining melting energy at the processing point. This segmentation allows each system to be optimized for its specific function, reducing the complexity and power requirements of the electron beam system compared to using it for both preheating and melting

Inventive Principle:
Principle #1Segmentation

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 enables the production of complex three-dimensional components with lower energy input, reduced material waste, and improved precision, allowing for continuous operation and efficient material deposition with minimal disruption to vacuum conditions.

Implementation Method 1

the wire is directly preheated electrically by means of resistance heating or inductively

Methodology Applied
Scientific EffectResistance heating: Joule Heating

Implementation Method 2

the wire is directly preheated electrically by means of resistance heating or inductively

Methodology Applied
Scientific EffectInductive heating: Induction Heating

Implementation Method 3

the melting energy is applied by a laser beam

Methodology Applied
Scientific EffectLaser heating: Laser

Data Source

PatentEP3322554B1Method for the additive manufacture of metallic components
Publication Date: 2023.06.07 EVOBEAM
  • EP3322554B1 patent drawingFigure 1
  • EP3322554B1 patent drawingFigure 2

AI summary

The invention relates to a method for the additive manufacture of three-dimensional metallic components (12), said components (12) being built layer-by-layer or section-by-section under vacuum conditions by fusing a metallic material with the component (12) at a machining point by means of a radiation source with a high energy density. In order to keep the energy applied to the machining point by the radiation itself relatively low, the metallic material is supplied in the form of a wire (28) which is preheated under vacuum conditions before reaching the machining point.