WC Carbide Cutting Tool Surface Stress for Titanium Alloy Wear

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Titanium alloys are difficult to process due to high reactivity leading to adhesion and chipping issues with cutting tools, and existing methods fail to provide sufficient wearing resistance and tool lifetime improvement.

Innovation Solution

A cutting tool made of cemented carbide with a first hard phase of WC particles and a binder phase containing Co or Ni, featuring a surface layer with 1.0 GPa or more compressive residual stress and a thickness equal to or less than the average particle diameter, which inhibits crushing and adhesion, enhancing wearing resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a thick surface layer is formed on the cutting tool, then wearing resistance is improved, but the tool becomes more prone to chipping and adhesion issues

Engineering Contradiction:
Improvewearing resistanceVSAvoidchipping and adhesion
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies a surface layer with specific properties (compressive residual stress of 1.0 GPa or more) only to the surface region of the cutting tool, while the interior maintains different characteristics. This localized treatment improves wearing resistance at the surface without adversely affecting the overall tool structure, resolving the contradiction between surface durability and structural integrity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the physical parameter of compressive residual stress in the surface layer to 1.0 GPa or more, which fundamentally alters the surface properties to resist wearing while preventing chipping and adhesion. This parameter change allows simultaneous improvement of wearing resistance and reduction of harmful surface effects.

Inventive Principle:
Principle #35Parameter changes

2Strength

If compressive residual stress is applied to the surface layer, then chipping resistance is improved, but the surface layer thickness must be precisely controlled

Engineering Contradiction:
Improvechipping resistanceVSAvoidsurface layer thickness control
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent specifies a precise parameter range for surface layer thickness (0.5 μm to 5.0 μm) and compressive residual stress (1.0 GPa or more). By defining these critical parameters, the invention enables controlled manufacturing that achieves chipping resistance while maintaining acceptable tolerance levels, resolving the contradiction between strength improvement and manufacturing precision requirements.

Inventive Principle:
Principle #35Parameter changes

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 exhibits improved wearing resistance and extended lifetime when processing titanium alloys, particularly under high-speed conditions, by preventing damage from adhesion and chipping.

Implementation Method 1

On a surface of a plain part in a rake face of the cutting tool, 1.0 GPa or more of a compressive residual stress is applied to the first hard phase

Methodology Applied
Scientific EffectCompressive residual stress:

Data Source

PatentEP4104957B1Cutting tool
Publication Date: 2024.05.15 SUMITOMO ELECTRIC INDUSTRIES LTD
  • EP4104957B1 patent drawingFigure 1
  • EP4104957B1 patent drawingFigure 2
  • EP4104957B1 patent drawingFigure 3

AI summary

A cutting tool according to an aspect of the present disclosure is made of a cemented carbide including a first hard phase and a binder phase. The first hard phase is composed of WC particles. The binder phase contains at least one element selected from Co and Ni. The cutting tool includes a main body part and a surface layer part provided on a surface of the main body part. A thickness of the surface layer part is equal to or less than an average particle diameter of the first hard phase. On a surface of a plain part in a rake face, 1.0 GPa or more of a compressive residual stress is applied to the first hard phase. A ratio (B/A) of the average particle diameter (B) of the first hard phase on the surface of the plain part in the rake face to an average particle diameter (A) of the first hard phase on a cross section of the main body part is 0.7 or more and less than 1.