Laser Debrazing of Brazed Joints for Component Reuse

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for dismantling cohesive metal connections, such as those in car bodies, are either costly, time-consuming, or not economically viable, leading to significant greenhouse gas emissions during recycling and limiting the reuse of components.

Innovation Solution

A method involving laser soldering to non-destructively separate metal components by directing a laser beam at the cohesive connection to melt the solder material while avoiding the component material's melting, followed by removal using a fluid flow with kinetic energy, allowing for the reuse of separated components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If established joining methods (screw, weld) are used, then strong mechanical connection is achieved, but non-removable and costly/dis time-consuming for disassembly

Engineering Contradiction:
Improvejoint strengthVSAvoiddisassembly ease
Core Design Contradiction:
StrengthVSEase of repair

Solution Approach 1:

The joint is segmented into three distinct components: base material, solder material, and filler material. This segmentation allows selective removal of the solder layer while preserving the base materials, enabling easy disassembly while maintaining strong initial connection through the solder-filler-material interface

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solder material's melting point is deliberately chosen to be between the base material melting point and room temperature. This parameter change enables selective melting and removal of the solder layer through controlled heating, allowing non-destructive disassembly while maintaining joint strength during assembly

Inventive Principle:
Principle #35Parameter changes

2Ease of repair

If thermal recycling (melting down) is used, then metal reuse is achieved, but significant greenhouse gas emissions occur

Engineering Contradiction:
Improvecomponent reuseVSAvoidgreenhouse gas emissions
Core Design Contradiction:
Ease of repairVSObject-generated harmful factors

Solution Approach 1:

The solder material is extracted from the joint through selective melting and removal, separating it from the valuable base materials. This extraction enables reuse of the base materials without complete melting and recycling, significantly reducing greenhouse gas emissions associated with thermal recycling while maintaining component integrity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The solder material is discarded as a removable layer while the base materials are recovered for reuse. This selective discarding and recovering approach allows direct reuse of high-value components without energy-intensive melting and recasting, reducing emissions while maintaining material circularity

Inventive Principle:
Principle #34Discarding and recovering

3Productivity

If solder material removal is attempted, then joint separation is achieved, but component material may melt or microstructure altered

Engineering Contradiction:
Improveseparation efficiencyVSAvoidcomponent integrity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The heating process is localized to the solder material layer through controlled energy application. The solder material's intermediate melting point enables selective local melting without affecting the base materials, ensuring separation efficiency while preserving component integrity and microstructure

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The solder material undergoes phase transition from solid to liquid at its characteristic melting point, which is between the base material melting point and room temperature. This phase transition enables clean separation through controlled heating while the base materials remain in solid phase, maintaining their structural integrity

Inventive Principle:
Principle #36Phase transitions

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

Enables the safe, effective, and economical separation of soldered connections without damaging the components, reducing greenhouse gas emissions and allowing for further mechanical processing and reuse.

Implementation Method 1

the focal spot of a laser beam is directed at a joining area of the metallurgical joint with a power density sufficient to melt a solder material and sufficient to at least prevent the melting of the component material

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

A temperature should be reached at which the solder material has a viscosity suitable for removal

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

the molten solder material is removed from the joining area by means of at least one fluid flow that has kinetic energy

Methodology Applied
Scientific EffectFluid flow with kinetic energy: Jet

Implementation Method 4

The liquid solder material is thereby blown away from the component surface

Methodology Applied
Scientific EffectFluid spray: Fluid Spray

Data Source

PatentEP3967434B1Method for non-destructive separation of a brazed joint
Publication Date: 2023.12.27 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV

AI summary

In the method for the non-destructive separation of a soldered joint on at least two metallic components joined by soldering, so that the separated components are available for mechanical processing in a closed loop, the focal spot of a laser beam is directed at a joining area of ​​the bonded joint with a power density sufficient to melt the solder material and at least sufficient to prevent melting of the component material, and with a forward movement of the focal spot. The molten solder material is removed from the joining area by means of at least one fluid flow possessing kinetic energy, and the components are separated from each other either continuously or only after the bonded solder joint has been completely severed. At least one of the components is then reused.