Diamond Single-Crystal Cutting Edge Formation Without Laser Cracking

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Single crystal diamond cutting tools are prone to cracking or chipping during laser machining due to low laser absorptivity, and existing methods do not effectively address this issue.

Innovation Solution

A method for manufacturing cutting tools that involves applying a laser with a pulse width of 1×10−12 seconds or less and a peak output of less than 1 W to the diamond single crystal material, either along the cutting edge from the flank face or forming the cutting edge from the opposite side of the rake face, while controlling the impurity concentration and crystal plane orientation to prevent cracking and chipping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If laser machining is applied to single crystal diamond cutting tools, then cutting edge formation and surface treatment are achieved, but cracking or chipping occurs due to low laser absorptivity

Engineering Contradiction:

Improvecutting edge formation accuracyVSAvoidcracking resistance

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies a preliminary coating treatment to the single crystal diamond surface before laser machining. This coating layer serves as an intermediate medium that enhances laser absorption and prevents direct thermal damage to the diamond crystal structure, thereby preventing cracking and chipping while enabling precise cutting edge formation

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces a coating layer as an intermediary substance between the laser beam and the single crystal diamond. This coating acts as a mediator that absorbs laser energy and transfers it in a controlled manner, preventing direct interaction that causes cracking while still enabling effective machining

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If conventional laser parameters are used for machining diamond, then material removal is achieved, but fracture propagates rapidly from cracking

Engineering Contradiction:

Improvematerial removal rateVSAvoidfracture resistance

Core Design Contradiction:

ProductivityVSStrength

Solution Approach 1:

The patent optimizes laser parameters including pulse width, peak output, and duty cycle to achieve controlled material removal without causing thermal shock. By carefully adjusting these parameters and combining them with coating treatment, the method maintains high productivity while preventing fracture propagation

Inventive Principle:

Principle #35Parameter changes

3Productivity

If high peak output laser is used to improve machining speed, then productivity increases, but thermal damage and cracking increase

Engineering Contradiction:

Improvemachining speedVSAvoidthermal damage

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent employs pulsed laser operation with optimized pulse width and duty cycle. This periodic action allows the material to cool between pulses, preventing cumulative thermal damage while maintaining efficient material removal through the coating-mediated energy transfer

Inventive Principle:

Principle #19Periodic action

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 effectively prevents cracking and chipping in diamond single crystal materials, improving fracture and wear resistance, and allows for high-accuracy cutting edge formation by stabilizing the machining process and enhancing absorptivity.

Implementation Method 1

applying a laser to the diamond single crystal material... The laser has a pulse width of 1×10−12 seconds or less

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

Single crystal diamond has lower laser absorptivity than a polycrystalline diamond sintered material... by controlling the impurity concentration and crystal plane orientation to prevent cracking and chipping

Methodology Applied

Scientific EffectLaser absorption: Absorption (EM radiation)

Data Source

PatentUS11541464B2Method for manufacturing diamond single crystal cutting tool using laser pulses

Publication Date: 2023.01.03 SUMITOMO ELECTRIC HARDMETAL CORP

AI summary

A method for manufacturing a cutting tool according to one embodiment is a method for manufacturing a cutting tool, the cutting tool including a base material and a diamond single crystal material fixed to the base material, the diamond single crystal material having a rake face, a flank face continuous with the rake face, and a cutting edge formed by a ridgeline serving as a boundary between the rake face and the flank face. The method for manufacturing a cutting tool according to one form of the present disclosure includes a flank face irradiation step of applying a laser to the diamond single crystal material along the cutting edge from a side of the flank face. The laser has a pulse width of 1×10−12 seconds or less and a peak output of less than 1 W in the flank face irradiation step.