Extrusion Die Nitride Layer for Honeycomb Molding

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Solution Overview

Problem

Dies for extrusion molding used in producing honeycomb structured bodies, especially those made of hard materials like silicon carbide, suffer from machining-induced defects and wear, leading to reduced lifespan due to abrasion and uneven cell wall formation.

Innovation Solution

A die with a nitride layer formed by oxidizing and then removing the machining-affected layer through ion implantation, providing a harder, more durable surface that reduces wear and maintains shape integrity during repeated extrusion molding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If machining with a cutting tool or electrical discharge machining is used to produce the die, then the die can be manufactured with the required shape, but the machined surface develops cracks and defects that reduce die life

Engineering Contradiction:
Improvedie manufacturingVSAvoiddie life
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies preliminary action by performing surface treatment (oxidation followed by nitride layer formation) on the die surface before actual use. This pre-treatment creates a protective layer that prevents crack propagation and reduces wear, thereby extending die life while maintaining manufacturability through conventional machining methods

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent creates a composite structure by forming a nitride layer (such as tungsten carbonitride) on the die surface. This composite material combines the base die material with a harder, more wear-resistant surface layer, resolving the contradiction between ease of manufacture and reliability by providing both manufacturability and enhanced durability

Inventive Principle:
Principle #40Composite materials

2Reliability

If the die surface is hardened to increase abrasion resistance, then die life is extended, but the machining process becomes more complex

Engineering Contradiction:
Improveabrasion resistanceVSAvoidsurface treatment process
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the chemical composition and physical properties of the die surface through controlled oxidation and nitridation processes. By adjusting parameters such as temperature, atmosphere composition, and treatment time, the surface is transformed into a harder, more abrasion-resistant state without fundamentally changing the die's overall structure or requiring additional complex equipment

Inventive Principle:
Principle #35Parameter changes

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

The nitride layer enhances the die's abrasion resistance and extends its lifespan by preventing surface wear and ensuring consistent cell wall thickness, improving the quality and longevity of honeycomb structured bodies produced.

Implementation Method 1

forming an oxidized layer by heating the machining-affected layer to oxidize the layer

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

nitriding the treated surface by ion implantation to form a nitride layer

Methodology Applied
Scientific EffectIon implantation: Ion Implantation

Data Source

PatentEP2832511B1Die for extrusion molding, production method for die for extrusion molding, and production method for honeycomb structure
Publication Date: 2016.06.01 IBIDEN CO LTD
  • EP2832511B1 patent drawingFigure 1(a)~1(b)
  • EP2832511B1 patent drawingFigure 2~3
  • EP2832511B1 patent drawingFigure 4

AI summary

The die for extrusion molding of the present invention includes: a first face; a second face formed opposite the first face; a raw material supply section with a first through hole that extends from the first face toward the second face; and a molding section with a second through hole that extends from the second face toward the first face so as to communicate with the first through hole, wherein the die is obtainable through the steps of: machining a material of the die to form the material into a predetermined shape and to form a machining-affected layer on the inner wall surface of the second through hole in the molding section; forming an oxidized layer by heating the machining-affected layer to oxidize the layer so as to convert the machining-affected layer into an oxidized layer; removing the oxidized layer so that a treated surface is formed; and nitriding the treated surface by ion implantation to form a nitride layer.