Surface-Coated Cutting Tool with Ti Multilayers for Deposition Resistance

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Solution Overview

Problem

Existing surface-coated cutting tools face challenges with deposition resistance, as they are either rough on the cutting edge portion or have insufficient deposition resistance, leading to inadequate performance in high-temperature cutting operations.

Innovation Solution

A surface-coated cutting tool with a multilayer structure containing titanium, featuring a titanium carbide and titanium nitride layer stack, and an aluminum oxide layer, along with voids in the interface between the inner and outer layers, to enhance deposition resistance and maintain wear resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a conventional coating is applied to improve wear resistance, then wear resistance is improved, but deposition resistance remains insufficient

Engineering Contradiction:
Improvewear resistanceVSAvoiddeposition resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The coating is divided into multiple functional layers: an inner layer containing an aluminum oxide layer for deposition resistance, and an outer layer containing titanium carbide and titanium nitride for wear resistance. This segmentation allows each layer to specialize in one function, resolving the contradiction between wear resistance and deposition resistance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coating uses composite material structure combining different ceramic materials (aluminum oxide, titanium carbide, titanium nitride) with distinct properties. The inner layer uses aluminum oxide for its non-stick properties, while the outer layer uses titanium carbide and nitride for hardness and wear resistance, achieving both requirements simultaneously.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the coating surface is made rough to increase deposition resistance, then deposition resistance is improved, but cutting edge quality deteriorates

Engineering Contradiction:
Improvedeposition resistanceVSAvoidcutting edge quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The coating applies different surface qualities to different regions: the inner layer provides a slightly rough surface for deposition resistance, while the outer layer provides a smooth, hard surface for cutting edge quality. This local differentiation resolves the contradiction between deposition resistance and cutting edge quality.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3470153B1Surface-coated cutting tool
Publication Date: 2022.08.03 SUMITOMO ELECTRIC HARDMETAL CORP

AI summary

A surface-coated cutting tool includes a substrate and a coating that is disposed on the substrate and formed so as to cover at least a portion of a flank face, in which the coating includes an inner layer and an outer layer formed on the inner layer, the inner layer is formed of at least one layer and includes an aluminum oxide layer as a layer in contact with the outer layer, the outer layer has a multilayer structure that includes three or more layers stacked on top of one another, and each of the layers that constitute the multilayer structure contains titanium.