Optical Unit Temperature Control in 3D Powder Bed Fusion

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing three-dimensional powder bed fusion technologies face inaccuracies and decalibration due to uneven heating and varying operating temperatures within the irradiation device, leading to suboptimal quality in produced work pieces.

Innovation Solution

An apparatus with a control unit that adjusts the temperature of the optical units and shielding gas within the process chamber to maintain consistent operating conditions, using heat transfer arrangements and feedback loops to stabilize temperatures and reduce thermal expansion effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the irradiation device operates for extended periods, then productivity is improved, but temperature variations cause inaccuracies and decalibration

Engineering Contradiction:
Improveproduction rateVSAvoidirradiation accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent implements feedback control by continuously monitoring the temperature of optical elements and adjusting cooling parameters accordingly. Temperature sensors detect thermal variations in real-time, and the control system modifies cooling gas flow or cooling element operation to maintain optimal temperature ranges, thereby preserving irradiation accuracy during extended production periods.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent actively manages temperature parameters by introducing cooling mechanisms that adjust thermal conditions of optical elements. By changing the temperature parameter through controlled cooling, the system prevents thermal expansion and refractive index changes that would otherwise degrade irradiation accuracy over time.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If cooling is applied to optical elements, then temperature stability is improved, but device complexity increases

Engineering Contradiction:
Improvetemperature stabilityVSAvoidcooling system complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent introduces cooling gas as an intermediary medium between the heat-generating optical elements and the environment. The cooling gas absorbs excess heat from optical elements through convection and thermal conduction, transporting it away from critical components. This intermediary approach provides effective temperature control while avoiding direct mechanical contact that would complicate the system further.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 accurate and high-quality production of three-dimensional work pieces by maintaining homogeneous temperature distribution across optical elements and within the process chamber, thereby reducing inaccuracies and achieving stable operating conditions over extended periods.

Implementation Method 1

a heat transfer arrangement (38) configured to transfer heat generated by a heat source (40) of the heat transfer arrangement to the at least one optical unit (26, 32)

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

The laser radiation penetrating into the powder layer causes heating and consequently melting or sintering of the raw material powder particles

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 3

heating and consequently melting or sintering of the raw material powder particles

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 4

heating and consequently melting or sintering of the raw material powder particles

Methodology Applied
Scientific EffectSintering: Sintering

Data Source

PatentEP3321005B1Apparatus for producing a three-dimensional work piece with process temperature control
Publication Date: 2021.09.01 NIKON SLM SOLUTIONS AG
  • EP3321005B1 patent drawingFigure 1
  • EP3321005B1 patent drawingFigure 2

AI summary

An apparatus (10) for producing a three-dimensional work piece (12) comprises a process chamber (14) accommodating a carrier (16) for receiving a raw material powder (18) and an irradiation device (20) for selectively irradiating electromagnetic or particle radiation onto the raw material powder (18) applied onto the carrier (16) in order to produce the work piece (12) from said raw material powder (18) by an additive layer construction method, the irradiation device (20) comprising at least one radiation source (22, 24) and at least one optical unit (26, 32) with a plurality of optical elements (28, 34). A heat transfer arrangement (38) is configured to transfer heat generated by a heat source (40) to the at least one optical unit (26, 32) of the irradiation device (20). The apparatus further comprises a control unit (42) configured to control the heat transfer arrangement (38) so as to adjust a temperature of the at least one optical unit (26, 32) of the irradiation device (20).