Induction Sintering Metal Foam Thin Films

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Solution Overview

Problem

Existing methods struggle to manufacture metal foams with uniformly formed pores and excellent mechanical strength, particularly in the form of thin films or sheets, due to difficulties in achieving desired porosity and processability.

Innovation Solution

The method involves induction heating of a metal foam using an electromagnetic field, applying it to a green structure composed of a conductive magnetic metal with high relative magnetic permeability and conductivity, which generates Joule heat for sintering, allowing for the production of metal foams with controlled porosity and mechanical strength in thin film or sheet form.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional sintering methods are used to manufacture metal foam, then porosity can be achieved, but uniform pore formation and mechanical strength deteriorate

Engineering Contradiction:
Improveuniform pore formationVSAvoidmechanical strength
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The patent employs induction heating to rapidly elevate the sintering temperature to approximately 1,000°C, maintaining it for a brief duration of 5-30 minutes. This rapid heating and controlled holding parameter regime enables uniform pore formation while preserving mechanical strength, resolving the contradiction between manufacturing precision and strength in metal foam production.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If metal foam is manufactured in thin film form, then processability improves, but mechanical strength and porosity control deteriorate

Engineering Contradiction:
Improveprocessability of thin filmVSAvoidmechanical strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent applies a binder coating to the green body before sintering, which serves as a preliminary protective measure. During the rapid induction heating process, this binder layer prevents excessive oxidation and structural collapse of the thin film, enabling successful manufacturing of thin metal foam films with both good processability and maintained mechanical strength.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If sintering time is extended to improve porosity, then pore formation improves, but productivity deteriorates

Engineering Contradiction:
Improveporosity controlVSAvoidproduction efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent replaces conventional slow thermal conduction heating with electromagnetic induction heating, which rapidly generates heat directly within the metal particles through induced eddy currents. This substitution of heating mechanism achieves the desired porosity control in just 5-30 minutes, dramatically improving productivity compared to traditional extended sintering processes.

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

4Productivity

If rapid sintering is applied to improve productivity, then production speed improves, but uniform pore formation and mechanical strength deteriorate

Engineering Contradiction:
Improvesintering speedVSAvoiduniform pore formation
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent employs a periodic control strategy where the induction heating is applied in a controlled manner to rapidly reach the target temperature of 1,000°C, then maintained at this temperature for a specific duration of 5-30 minutes. This periodic heating profile ensures uniform pore formation and mechanical strength while maintaining high productivity, resolving the contradiction between sintering speed and manufacturing precision.

Inventive Principle:
Principle #19Periodic action

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 rapid production of metal foams with uniformly formed pores and excellent mechanical properties, ensuring desired porosity and processability, even in thin film or sheet form, thereby expanding their applications.

Implementation Method 1

a step of applying an electromagnetic field to a green structure comprising a metal component comprising at least a metal to which the induction heating method is applicable. Heat is generated in the metal by the application of the electromagnetic field to heat the structure, whereby it can be sintered

Methodology Applied
Scientific EffectInduction heating: Induction Heating

Implementation Method 2

eddy currents are generated in the metal, and Joule heating occurs due to the resistance of the metal

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 3

if an electromagnetic field is applied to a metal having a proper conductivity and magnetic permeability, eddy currents are generated in the metal

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3527307B1Method for manufacturing metal foam
Publication Date: 2023.05.03 LG CHEM LTD
  • EP3527307B1 patent drawingFigure 1

AI summary

The present application provides a method for manufacturing a metal foam. The present application can provide a method for manufacturing a metal foam, which is capable of forming a metal foam comprising uniformly formed pores and having excellent mechanical properties as well as the desired porosity, and a metal foam having the above characteristics. In addition, the present application can provide a method capable of forming a metal foam in which the above-mentioned physical properties are ensured, while being in the form of a thin film or sheet, within a fast process time, and such a metal foam.