cBN Sintered Compact Interface Design for Longer Cutting Tool Life
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The rapid improvement in mechanical parts has made it challenging to cut workpieces effectively, leading to a short life of cutting tools and increased costs.
Innovation Solution
A cubic boron nitride sintered material with a specific composition and production method, including forming an organic-substance-attached cubic boron nitride powder and mixing it with a binder powder, followed by sintering to achieve a long tool life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the content ratio of cubic boron nitride grains is increased to improve hardness, then the material becomes more suitable for cutting hard workpieces, but the binder phase content decreases leading to reduced binding strength and shorter tool life
Solution Approach 1:
The patent applies local quality by creating a carbon-enriched first region specifically at the interface between cBN grains and binder phase, rather than uniformly distributing carbon throughout the material. This localized carbon concentration (0.1-10 nm thickness) provides enhanced binding strength at the critical grain-binder interface while maintaining the overall high hardness of the low-cBN sintered material with 20-80 volume% cBN grains.
Solution Approach 2:
The patent changes the chemical composition parameter by introducing a carbon content gradient at the grain-binder interface. The first region has a carbon content larger than the average binder phase carbon content, creating a compositional transition zone that improves interfacial bonding. This parameter change allows the material to maintain both high hardness and extended tool life through optimized interface chemistry.
2Duration of action of moving object
If the binder phase content is increased to improve binding strength between grains, then tool life is extended, but the cubic boron nitride grain content decreases reducing material hardness
Solution Approach 1:
The patent applies local quality by creating a carbon-enriched first region specifically at the interface between cBN grains and binder phase, rather than uniformly distributing carbon throughout the material. This localized carbon concentration (0.1-10 nm thickness) provides enhanced binding strength at the critical grain-binder interface while maintaining the overall high hardness of the low-cBN sintered material with 20-80 volume% cBN grains.
Solution Approach 2:
The patent creates a composite structure with three distinct regions: cBN grains, binder phase, and a carbon-enriched first region at the interface. This composite approach combines the hardness of cBN with the binding strength of the binder phase enhanced by the carbon-rich interface layer, achieving both high hardness and extended tool life simultaneously.
3Adaptability or versatility
If conventional low-cBN sintered materials are used for cutting hardened steel, then the material can be applied to specific workpiece materials, but the rapid improvement in mechanical parts makes it difficult to cut workpieces effectively leading to short tool life
Solution Approach 1:
The patent changes the chemical composition parameter by introducing a carbon content gradient at the grain-binder interface. The first region has a carbon content larger than the average binder phase carbon content, creating a compositional transition zone that improves interfacial bonding. This parameter change allows the material to maintain both high hardness and extended tool life through optimized interface chemistry.
Solution Approach 2:
The patent applies local quality by creating a carbon-enriched first region specifically at the interface between cBN grains and binder phase, rather than uniformly distributing carbon throughout the material. This localized carbon concentration (0.1-10 nm thickness) provides enhanced binding strength at the critical grain-binder interface while maintaining the overall high hardness of the low-cBN sintered material with 20-80 volume% cBN grains.
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 described cubic boron nitride sintered material achieves a long life of cutting tools by optimizing the binding strength between cubic boron nitride grains and the binder phase, thereby enhancing tool durability and reducing costs.
Implementation Method 1
forming an organic-substance-attached cubic boron nitride powder by attaching an organic substance to a cubic boron nitride powder
Implementation Method 2
obtaining the cubic boron nitride sintered material by sintering the powder mixture
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A cubic boron nitride sintered material includes: more than or equal to 20 volume% and less than 80 volume% of cubic boron nitride grains; and more than 20 volume% and less than or equal to 80 volume% of a binder phase, wherein the binder phase includes at least one selected from a group consisting of a compound composed of at least one element selected from a group consisting of a group 4 element, a group 5 element, a group 6 element in a periodic table, and aluminum, and at least one element selected from a group consisting of nitrogen, carbon, boron, and oxygen, and a solid solution originated from the compound, and when a carbon content is measured from a cubic boron nitride grain into the binder phase in a direction perpendicular to an interface between the cubic boron nitride grain and the binder phase using TEM-EDX, a first region having a carbon content larger than an average value of a carbon content of the binder phase exists, the interface exists in the first region, and a length of the first region is more than or equal to 0.1 nm and less than or equal to 10 nm.