Core-Shell Cemented Carbide Composition for Steel-Reactive Wear

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Solution Overview

Problem

Existing cemented carbides with Ti-based compounds have inadequate resistance against reactivity with steel, limiting their mechanical strength and wear resistance.

Innovation Solution

The development of cemented carbide compositions featuring TiNbWCN and TiNbCN as source materials, with specific atomic ratios and microstructural configurations of WC, carbonitride, and an iron-group binder phase, enhancing mechanical strength and resistance against steel reactivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If Mo is added to composite carbonitride to improve mechanical strength, then hardness and wear resistance are enhanced, but resistance against reactivity with steel deteriorates

Engineering Contradiction:
Improvemechanical strengthVSAvoidreactivity with steel
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by replacing Mo with Nb in the composite carbonitride structure. Specifically, it uses TiNbWCN and TiNbCN compounds where Nb provides both the desired mechanical strength enhancement and improved resistance against reactivity with steel, thus resolving the contradiction through parameter optimization

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite carbonitride materials containing Ti, Nb, W, C, and N in specific ratios. The composite structure of TiNbWCN and TiNbCN combines the benefits of multiple elements: Ti for base strength, Nb for enhanced mechanical properties and reduced steel reactivity, W for hardness, and controlled C:N ratios for overall performance optimization

Inventive Principle:
Principle #40Composite materials

2Strength

If Ti-based compounds are used in cemented carbide, then wear resistance is improved, but resistance against reactivity with steel is insufficient

Engineering Contradiction:
Improvewear resistanceVSAvoidreactivity with steel
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the Ti-based compound composition by incorporating specific ratios of Nb and W along with controlled carbonitride content. The atomic ratios of C and N are precisely controlled (C: 0.4-0.6, N: 0.4-0.6) to achieve optimal balance between wear resistance and reduced steel reactivity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system where TiNbWCN and TiNbCN compounds are combined with WC and an iron-group binder phase. This composite structure leverages the synergistic effects of different materials: TiNbWCN/TiNbCN for wear resistance and reduced steel reactivity, WC for hardness, and the iron-group binder for toughness and binding

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP3613864B1Cemented carbide and method for preparing cemented carbide
Publication Date: 2021.12.29 SUMITOMO ELECTRIC INDUSTRIES LTD
  • EP3613864B1 patent drawingFigure 1

AI summary

Cemented carbide contains first hard-phase particles containing WC, second hard-phase particles which contain carbonitride containing at least Ti and Nb, and a metallic binder phase containing an iron-group element. The second hard-phase particle includes a granular core portion and a peripheral portion which covers at least a part of the core portion. The core portion contains composite carbonitride expressed as Ti1-X-YNbXWYC1-ZNZ, where Y is not smaller than 0 and not greater than 0.05 and Z is not smaller than 0.3 and not greater than 0.6. The peripheral portion is different in composition from the core portion.