cBN Sintered Material Composition 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 composition of more than 50 volume% and less than 80 volume% of cubic boron nitride grains, and more than 20 volume% and less than or equal to 50 volume% of a binder phase, where the binder phase includes specific compounds and solid solutions, and has a controlled oxygen content distribution at the interface between cBN grains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the content ratio of cubic boron nitride grains is increased to improve hardness, then the binding strength between grains decreases, but tool life is reduced
Solution Approach 1:
The patent optimizes the content ratio parameters of cBN grains (50-80 vol%) and binder phase (20-50 vol%) to achieve a balance between hardness and tool life. This parameter optimization allows the material to simultaneously possess sufficient hardness for cutting hardened steel and adequate binder phase for grain binding, resolving the contradiction between strength and duration of action
Solution Approach 2:
The patent creates a composite material system combining cBN grains with a specifically designed binder phase containing compounds of group 4-6 elements and aluminum with nitrogen, carbon, boron, and oxygen. This composite structure leverages the high hardness of cBN grains while the binder phase provides binding strength, achieving both hardness and tool life requirements
2Reliability
If oxygen content at interfaces is high, then oxidation resistance improves, but binding strength between cBN grains and binder phase decreases
Solution Approach 1:
The patent applies local quality control by managing oxygen distribution non-uniformly: allowing oxygen presence in regions for oxidation resistance while controlling and reducing oxygen content specifically at the interface regions between cBN grains and binder phase to maintain binding strength. This localized control resolves the contradiction between oxidation resistance and binding strength
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A cubic boron nitride sintered material includes: more than or equal to 50 volume% and less than 80 volume% of cubic boron nitride grains; and more than 20 volume% and less than or equal to 50 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 an oxygen content is measured in a direction perpendicular to an interface between cubic boron nitride grains using TEM-EDX, a first region having an oxygen content larger than an average value of an oxygen content of a cubic boron nitride grain exists, the interface exists in the first region, and a length of the first region along the direction perpendicular to the interface is more than or equal to 0.1 nm and less than or equal to 10 nm.