cBN Sintered Compact Interface Composition for Wear-Resistant Cutting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cubic boron nitride (cBN) tools used for cutting high-strength hardened steel experience unstable life due to rapid wear and defects caused by hard particles, leading to increased cutting resistance and premature failure.
Innovation Solution
A cBN sintered material with a specific composition comprising cubic boron nitride particles, a binding phase, and an interfacial phase containing aluminum, nitrogen, and oxygen, which enhances adhesion and stress absorption, preventing crack propagation and particle detachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If cBN tools are used for cutting high-strength hardened steel, then cutting capability is achieved, but tool life becomes unstable due to rapid wear and defects
Solution Approach 1:
An interfacial phase comprising aluminum, nitrogen, and oxygen is introduced between the cubic boron nitride particles and the binding phase. This interfacial phase acts as a mediator that improves adhesion and stress distribution, preventing crack propagation and particle detachment during cutting operations on high-strength hardened steel, thereby stabilizing tool life while maintaining cutting capability.
Solution Approach 2:
The sintered compact is designed as a composite material system with three distinct phases: cubic boron nitride particles (20-80 vol%), binding phase (10-50 vol%), and interfacial phase (5-20 vol%). This composite structure combines the hardness of cBN with the adhesive properties of the interfacial phase, resolving the contradiction between cutting capability and tool life stability.
2Strength
If the volume percentage of cubic boron nitride particles is increased to improve wear resistance, then hardness increases but adhesion between particles and binding phase deteriorates
Solution Approach 1:
The interfacial phase serves as an intermediary layer between the cubic boron nitride particles and the binding phase. Even when cBN particle content is high (20-80 vol%), this interfacial phase ensures adequate adhesion by providing a transition zone that bonds the hard particles to the binding matrix, preventing particle detachment during cutting.
Solution Approach 2:
The interfacial phase is localized at the boundaries between cBN particles and the binding phase, providing targeted adhesion enhancement only where needed at the interfaces. The bulk cBN particles maintain their inherent wear resistance, while the interfacial regions provide the necessary bonding, achieving both high hardness and good adhesion simultaneously.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A cubic boron nitride sintered material comprises cubic boron nitride particles, a binding phase, and an interfacial phase. The interfacial phase intervenes between the cubic boron nitride particles and the binding phase. The interfacial phase includes aluminum, nitrogen, boron, and oxygen. A total of an average value of the atomic concentrations of aluminum included in the interfacial phase and an average value of the atomic concentrations of nitrogen included in the interfacial phase is 50.0 at% or more. A ratio of an average value of the atomic concentrations of nitrogen included in the interfacial phase to an average value of the atomic concentrations of boron included in the interfacial phase is more than 1.00.