cBN Sintered Material Interface Composition to Prevent Tool Chipping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-cBN sintered materials used in cutting tools experience premature chipping due to weak bonding between cBN particles and the bonding material, leading to reduced tool lifetime and increased costs.
Innovation Solution
A cubic boron nitride sintered material with a bonding material containing metallic elements like titanium, zirconium, and tungsten, where these elements are concentrated at the interface with cBN particles to enhance bonding strength and reduce thermal cracking, thereby prolonging tool lifetime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the content ratio of cubic boron nitride particles is increased to achieve high hardness and wear resistance, then the cutting tool can effectively process hard materials, but the binding force between particles becomes weak causing unexpected chipping and reduced tool lifetime
Solution Approach 1:
The patent applies local quality by creating an interface region with enhanced metallic element concentration specifically at the boundary between cBN particles and bonding material. This localized compositional change strengthens the interface zone without altering the overall high-cBN composition, thereby maintaining hardness while improving particle binding and reducing chipping.
Solution Approach 2:
The patent changes the compositional parameter by requiring metallic elements to constitute 5-20 atomic% in the interface region, which is higher than in the bulk bonding material. This parameter change optimizes the balance between maintaining high cBN content for hardness and providing sufficient metallic bonding for particle attachment, resolving the contradiction between strength and reliability.
2Ease of manufacture
If conventional bonding materials are used to maintain simplicity and cost-effectiveness, then the manufacturing process remains straightforward, but the bonding strength between cBN particles and bonding material is insufficient leading to particle dropout
Solution Approach 1:
The patent modifies the bonding material composition by specifying that metallic elements (Ti, Zr, V, Nb, Hf, Ta, Cr, Re, Mo, or W) should constitute 5-20 atomic% in the interface region. This compositional parameter change enhances bonding strength through stronger metal-cBN interactions while maintaining a relatively simple sintered material structure that does not require complex multi-layer manufacturing processes.
Data Source
AI summary
A cubic boron nitride sintered material comprises cubic boron nitride particles and a bonding material, wherein the bonding material comprises at least one first metallic element selected from the group consisting of titanium, zirconium, vanadium, niobium, hafnium, tantalum, chromium, rhenium, molybdenum, and tungsten; cobalt; and aluminum; the cubic boron nitride sintered material has a first interface region sandwiched between an interface between the cubic boron nitride particles and the bonding material, and a first virtual line passing through a point 10 nm apart from the interface to the bonding material side; and when an element that is present at the highest concentration among the first metallic elements in the first interface region is defined as a first element, an atomic concentration of the first element in the first interface region is higher than an atomic concentration of the first element in the bonding material excluding the first interface region.