Cemented Carbide Composition for Uniform Carbonitride Distribution
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Solution Overview
Problem
Existing cemented carbide materials lack uniform distribution of composite carbonitride phases, leading to inadequate resistance against reactivity with steel, and there is a need for improved homogeneity in hardness and toughness.
Innovation Solution
The development of cemented carbide containing first hard-phase particles of WC, second hard-phase particles with a granular core and peripheral portion composed of composite carbonitride Ti1-X-YNbXWYC1-ZNZ, and a metallic binder phase with an iron-group element, where the core portion has a specific atomic ratio and particle size, and the peripheral portion enhances adhesion strength, achieving uniform distribution and improved mechanical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional cemented carbide materials are used, then manufacturing simplicity is maintained, but uniform distribution of composite carbonitride phases is insufficient
Solution Approach 1:
The second hard-phase particles are segmented into a core portion containing composite carbonitride (Ti1-X-YNbXWYC1-ZNZ) and a peripheral portion with different composition. This segmentation allows the core to provide wear resistance while the periphery enhances adhesion to the binder phase, achieving uniform distribution and improved homogeneity in hardness and toughness throughout the cemented carbide.
Solution Approach 2:
Different regions of the second hard-phase particles are given different compositions and properties: the core portion contains composite carbonitride for wear resistance, while the peripheral portion has a composition optimized for adhesion to the metallic binder phase. This local quality differentiation resolves the contradiction by enabling both uniform distribution and enhanced performance without excessive overall complexity.
2Reliability
If composite carbonitride phases are added to improve resistance against reactivity with steel, then material performance is enhanced, but homogeneity in hardness and toughness becomes insufficient
Solution Approach 1:
The cemented carbide is designed to have uniform distribution of second hard-phase particles throughout the material, with the area ratio of these particles at the surface differing by no more than 10 percentage points from the area ratio in the region extending 0.5 mm from the surface. This homogeneity in particle distribution ensures consistent hardness and toughness throughout the material while maintaining high resistance against reactivity with steel.
Solution Approach 2:
The invention uses a composite structure with first hard-phase particles (WC), second hard-phase particles (composite carbonitride Ti1-X-YNbXWYC1-ZNZ with core and periphery), and a metallic binder phase containing an iron-group element. This composite material approach enables both high resistance against reactivity with steel and homogeneous mechanical properties by carefully balancing the composition and distribution of different phases.
3Strength
If second hard-phase particles with core and peripheral structure are used, then adhesion strength is improved, but manufacturing complexity increases
Solution Approach 1:
The invention specifies precise compositional parameters for the composite carbonitride in the core portion (Ti1-X-YNbXWYC1-ZNZ where X is 0.05-0.20, Y is 0.00-0.05, and Z is 0.30-0.60) and controls the area ratio distribution (difference ≤10 percentage points between surface and 0.5 mm depth regions). These parameter changes enable improved adhesion strength through the peripheral portion while keeping manufacturing feasible through well-defined compositional ranges and distribution criteria.
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 results in cemented carbide with enhanced resistance against reactivity with steel, improved homogeneity in hardness and toughness, and increased mechanical strength, making it suitable for cutting tools.
Implementation Method 1
obtaining a sintered material by sintering the formed material
Data Source
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. The core portion contains composite carbonitride expressed as Ti1-X-YNbXWYC1-ZNZ, where X is not smaller than 0.1 and not greater than 0.2, 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 cemented carbide has an absolute value of a difference not greater than 10, between a ratio (%) of an area occupied by the second hard-phase particles at a surface thereof and a ratio (%) of an area occupied by the second hard-phase particles in a region extending from the surface by 0.5 mm in a direction of depth.