Laser-Formed CBN/PCD Cutting Edge for Sharpness and Fracture Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cutting tools with cubic boron nitride or polycrystalline diamond cutting edges face challenges in achieving a sharpness enhancement due to limitations in forming a round honed face with a radius of curvature of 10 µm or less using conventional polishing or electric discharge machining methods.
Innovation Solution
A cutting tool design featuring a cutting edge with a radius of curvature between 2 µm and 8 µm, achieved through laser irradiation, allowing for varying arithmetic average roughness along the cutting edge to enhance sharpness and fracture resistance, and enabling precise formation without repositioning during manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional polishing or electric discharge machining is used to form the round honed face, then the manufacturing process is simple and well-established, but the radius of curvature cannot be reduced to 10 µm or less, limiting cutting edge sharpness
Solution Approach 1:
The patent replaces conventional mechanical polishing or electric discharge machining with laser beam processing to form the round honed face. The laser beam irradiates the cutting edge portion, utilizing thermal energy to precisely control the radius of curvature to 10 µm or less, achieving superior sharpness that mechanical methods cannot attain
Solution Approach 2:
The patent changes the processing method from mechanical/electrical to thermal (laser) processing, and optimizes laser processing parameters including irradiation amount, scanning speed, and beam focus to precisely control the radius of curvature of the cutting edge within the target range
2Manufacturing precision
If the radius of curvature of the cutting edge is reduced to enhance sharpness, then cutting performance improves, but the cutting edge becomes more susceptible to fracture
Solution Approach 1:
The patent applies different surface qualities to different regions of the cutting edge. The round honed face has a controlled radius of curvature (10-50 µm) for optimal cutting sharpness, while the chamfer honed face provides a transition zone. This local differentiation allows the cutting edge to achieve both sharpness and fracture resistance by optimizing each region's geometry
Solution Approach 2:
The chamfer honed face acts as a cushioning zone before the round honed face. This pre-designed geometric feature with larger radius provides stress distribution and prevents stress concentration at the cutting edge, thereby preventing initial fractures while maintaining sharp cutting performance
3Strength
If the round honed face radius is increased to prevent fracture, then cutting edge strength improves, but cutting sharpness deteriorates
Solution Approach 1:
The patent segments the honed face into two distinct zones: the chamfer honed face with larger radius for strength and fracture prevention, and the round honed face with smaller radius (10-50 µm) for sharpness. This segmentation allows each zone to fulfill its specific function without compromise
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 cutting tool achieves improved sharpness and reduced workpiece adhesion, while varying radius and roughness along the cutting edge address different performance requirements, enhancing machining precision and preventing burrs and initial fractures.
Implementation Method 1
achieved through laser irradiation
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A cutting tool according to an aspect of the present disclosure includes a cutting edge portion which contains at least one of cubic boron nitride and polycrystalline diamond. The cutting edge portion includes a rake face, a flank face, and a cutting edge. The flank face is contiguous to the rake face. The cutting edge is provided as a ridge line between the rake face and the flank face. The radius of curvature of the cutting edge is 2 µm or more and 8 µm or less.