(Al,Cr,Ta)N Coating for High Temperature Wear Resistance

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Solution Overview

Problem

Existing (Cr,Al,Ta)N hard coatings for cutting tools require complex deposition processes with multiple layers and nanolayers of specific compositions and thicknesses, leading to high complexity and difficulty in coating tools with different dimensions and geometries, especially for high-speed cutting operations.

Innovation Solution

A simplified hard coating composition of (Al, Cr, Ta)N with a chemical formula (AlaCrbTac)N, where a = x•(1-c), b = (1-x)•(1-c), and 0.60 ≤ x ≤ 0.70, 0.01 ≤ c ≤ 0.5, exhibiting a X-ray diffraction peak intensity ratio I200/(I200+I111) ≥ 0.25, which can be deposited using reactive arc ion plating techniques, allowing for variation in peak intensity ratio along the layer thickness and adjustable properties like residual stress and Young's modulus.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex multilayer and nanolayer structures with specific compositions are used, then wear resistance is improved, but device complexity increases

Engineering Contradiction:
Improvewear resistanceVSAvoidcoating process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple layers and nanolayers with different compositions into a single-layer (Cr,Al,Ta)N coating structure. This single layer maintains the wear resistance properties previously requiring complex multilayer structures by integrating the functional benefits of different material compositions into one unified coating deposited from a CrAlTa-containing target.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single-layer (Cr,Al,Ta)N coating performs multiple functions that previously required separate layers. By optimizing the composition ratios of Cr, Al, and Ta within this single layer, the coating simultaneously provides wear resistance, adhesion, and protective properties against reactive materials, eliminating the need for specialized sublayers.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If multiple targets with different compositions are used for deposition, then coating performance is improved, but ease of manufacture decreases

Engineering Contradiction:
Improvecoating performanceVSAvoidcoating deposition ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent combines Cr, Al, and Ta elements into a single CrAlTa-containing target material. This unified target simplifies the deposition process by eliminating the need to switch between multiple targets with different compositions, while still achieving the optimized coating performance through controlled release of all three elements during arc ion plating.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent optimizes the composition parameters of the CrAlTa target and deposition conditions to achieve the desired coating properties from a single target. By adjusting the ratios of Cr, Al, and Ta in the target material and controlling deposition parameters, the coating performance previously requiring multiple targets is achieved with one target.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If nanolayers with different element compositions are deposited alternately, then wear resistance is improved, but difficulty of detecting and measuring increases

Engineering Contradiction:
Improvewear resistanceVSAvoidnanolayer composition control
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent merges the alternating nanolayer structure into a homogeneous single-layer deposition. Instead of depositing alternating nanolayers A and B with different compositions, the CrAlTa target releases all elements simultaneously during deposition, creating a uniform coating that is easier to control and measure while maintaining wear resistance.

Inventive Principle:
Principle #5Merging (Combining)

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 coating provides excellent wear resistance and improved mechanical properties at elevated temperatures, with reduced complexity in the coating process and ability to adapt to various tool geometries, achieving high abrasion resistance and plasticity while maintaining high hardness.

Implementation Method 1

deposited from CrAlTa-containing targets in a reactive nitrogen atmosphere by using arc ion plating techniques

Methodology Applied
Scientific EffectArc ion plating: Arc Evaporation

Implementation Method 2

reactive arc ion plating pvd method for depositing hard coatings

Methodology Applied
Scientific EffectPhysical vapor deposition: Physical Vapour Deposition

Data Source

PatentEP3068920B1(al,cr,ta)n coating for enhanced high temperature resistance
Publication Date: 2019.04.03 OERLIKON SURFACE SOLUTIONS AG PFAFFIKON
  • EP3068920B1 patent drawingFigure 1
  • EP3068920B1 patent drawingFigure 2a~2f
  • EP3068920B1 patent drawingFigure 3a~3f

AI summary

The application relates to a hard coating comprising at least one layer comprising chromium, aluminium, tantalum and nitrogen as main components and a chemical composition (AlaCrbTac)N in which the following conditions are satisfied: a = x.(1-c), b = (1-x).(1-c), 0.60 ≤ x ≤ 0.70, and 0.01 ≤ c ≤ 0.5 and having an X-ray diffraction peak intensity ratio 1200 /(1200 +l111) ≥ 0.25. The application also relates to a reactive arc ion plating pvd process for making the hard coating.