cBN Sintered Material With Carbon-Mediated Grain Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-cubic boron nitride sintered materials used in cutting tools tend to experience sporadic chipping due to weak binding strength between cubic boron nitride grains, leading to a short tool life and increased costs.
Innovation Solution
A method of producing a cubic boron nitride sintered material involving the formation of an organic cubic boron nitride powder by attaching an organic substance onto the cubic boron nitride source material powder, followed by mixing with a binder source material powder containing WC, Co, and Al, and sintering to create a material with increased binding strength between grains through uniform carbon distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a high-cBN sintered material is used to increase hardness and cutting performance, then cutting ability is improved, but binding strength between grains becomes weak leading to sporadic chipping
Solution Approach 1:
Carbon is introduced as an intermediary substance at the interface between cBN grains to enhance binding strength. The carbon forms a bonding layer that mediates the connection between adjacent cBN grains, preventing sporadic chipping while preserving the high hardness of the material.
Solution Approach 2:
Carbon is selectively distributed at the interface regions between cBN grains rather than uniformly throughout the material. This local concentration of carbon at grain boundaries provides enhanced bonding precisely where needed, without compromising the overall hardness of the high-cBN structure.
2Strength
If cubic boron nitride grain content is increased to improve cutting performance, then material hardness increases, but tool life decreases due to grain falling
Solution Approach 1:
Carbon acts as a bonding intermediary that strengthens the connection between cBN grains, enabling the material to maintain high grain content for hardness while preventing grain detachment that would otherwise limit tool life.
Solution Approach 2:
The sintered material is designed as a composite structure combining cBN grains with carbon at the interfaces. This composite approach allows the material to simultaneously achieve high hardness from the cBN grains and extended tool life from the carbon-bonded grain structure.
3Reliability
If binder content is increased to improve binding strength, then grain binding improves, but cubic boron nitride grain content decreases
Solution Approach 1:
Carbon serves as a minimal-binder intermediary that provides effective grain bonding without requiring large volumes of binder material. This allows the system to achieve strong grain binding while maintaining high cBN grain content.
Solution Approach 2:
The bonding mechanism is changed from traditional binder-based bonding to carbon-based interface bonding. This parameter change in the bonding mechanism allows for reduced binder content while maintaining or improving binding strength through the carbon intermediary at grain interfaces.
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 method results in a cubic boron nitride sintered material with enhanced binding strength and a longer tool life, reducing the likelihood of grain falling and extending the cutting tool's lifespan.
Implementation Method 1
forming an organic cubic boron nitride powder by attaching an organic substance onto a cubic boron nitride source material powder
Implementation Method 2
obtaining the cubic boron nitride sintered material by sintering the powder mixture
Data Source
AI summary
A method of producing a cubic boron nitride sintered material includes: forming an organic cubic boron nitride powder by attaching an organic substance onto a cubic boron nitride source material powder; preparing a powder mixture including more than or equal to 85 volume % and less than 100 volume % of the organic cubic boron nitride powder and a remainder of a binder source material powder by mixing the organic cubic boron nitride powder and the binder source material powder, the binder source material powder including WC, Co and Al; and obtaining the cubic boron nitride sintered material by sintering the powder mixture.