Nanostructured Composite Coating for Hardness and Adhesion

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Solution Overview

Problem

Existing methods for forming hard thin layers, such as magnetron sputtering and cathodic arc evaporation, fail to achieve high adhesion and low surface roughness for applications requiring thicknesses less than 2 micrometers, particularly in highly stressed thermo-mechanical environments, and cannot produce layers with hardness greater than 20 GPa and thickness less than 200 nm.

Innovation Solution

A magnetron cathode sputtering process in reactive co-sputtering mode is used to deposit a nanostructured composite coating based on titanium, zirconium, boron, and nitrogen, with specific power ratios and nitrogen content in the gas mixture, to achieve a hardness greater than 20 GPa and thickness less than 200 nm, while maintaining low surface roughness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If magnetron sputtering is used to deposit hard thin layers, then the layer composition precision and surface roughness are improved, but the adhesion level and hardness for thicknesses less than 2 micrometers deteriorate

Engineering Contradiction:
Improvesurface roughnessVSAvoidadhesion level
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

An intermediate layer is deposited before the final hard coating layer to prepare the surface for better adhesion. This preliminary layer modifies the substrate surface properties, enabling subsequent layers to adhere properly even at thin thicknesses

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

A nanocomposite structure is created by combining different materials in specific layers. The intermediate layer has different properties than the final hard coating, creating a gradient structure that optimizes both adhesion to the substrate and surface quality

Inventive Principle:
Principle #40Composite materials

2Reliability

If cathodic arc evaporation is used to improve adhesion through high ionization rate, then the adhesion level is improved, but the surface roughness increases significantly

Engineering Contradiction:
Improveadhesion levelVSAvoidsurface roughness
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The intermediate layer is deposited first to provide a foundation that can tolerate the roughness from cathodic arc evaporation, while still providing adequate adhesion. The final hard coating is then deposited on this prepared surface

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The coating process is divided into separate stages with different deposition methods. The intermediate layer uses one method optimized for adhesion, while the final layer uses another method optimized for surface quality and hardness

Inventive Principle:
Principle #1Segmentation

3Manufacturing precision

If hard coating thickness is reduced to less than 200 nm to maintain geometric precision, then the geometric precision is improved, but the hardness and adhesion levels deteriorate

Engineering Contradiction:
Improvegeometric precisionVSAvoidhardness
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

A nanocomposite structure with multiple layers of different materials and properties is created. This composite structure achieves high hardness and adhesion even at total thicknesses less than 200 nm, preserving geometric precision while providing protective functionality

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Different layers have different local properties optimized for their specific functions. The intermediate layer provides adhesion, while the final nanocomposite layer provides hardness and wear resistance, with each layer tailored to its required performance

Inventive Principle:
Principle #3Local quality

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 process enables the formation of extremely hard nanostructured coatings with high adhesion and reduced surface roughness, suitable for applications like razor blades and micro-electromechanical systems (MEMs), where high hardness and thinness are critical without compromising geometric precision.

Implementation Method 1

deposition by magnetron cathode sputtering of a layer of titanium, on at least one surface of said support

Methodology Applied
Scientific EffectSputtering: Sputtering

Implementation Method 2

the process of evaporation by cathodic arc is currently used because it makes it possible to obtain adhesion levels of the hard layer on the coated part very high due to the very high rate of ionization of the vapor generated by the technique of evaporation by cathodic arc which is about 90%

Methodology Applied
Scientific EffectCathodic arc evaporation: Cathodic Arc Deposition

Data Source

PatentEP2045352B1Method of obtaining a hard surface on the nanometric scale
Publication Date: 2012.06.13 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP2045352B1 patent drawingFigure 1~2
  • EP2045352B1 patent drawingFigure 3
  • EP2045352B1 patent drawingFigure 4~5

AI summary

The process for the formation of a nanocomposite material coating having a thickness of lower than 200 nm and a hardness of >= 20 GPa on a support (6), comprises depositing a titanium layer (7) on a surface of the support under a partial pressure (1 Pa) of argon by cathodic magnetron sputtering, depositing a titanium nitride layer (8) on the titanium layer by introducing nitrogen in an enclosure of cathodic sputtering, and depositing a layer of nanostructured composite material (9) on the titanium nitride layer in an active co-sputtering mode. The process for the formation of a nanocomposite material coating having a thickness of lower than 200 nm and a hardness of >= 20 GPa on a support (6), comprises depositing a titanium layer (7) on a surface of the support under a partial pressure (1 Pa) of argon by cathodic magnetron sputtering, depositing a titanium nitride layer (8) on the titanium layer by introducing nitrogen in an enclosure of cathodic sputtering, and depositing a layer of nanostructured composite material (9) on the titanium nitride layer in an active co-sputtering mode by application of power X on a source of titanium target 3 and power Y on target 2 source of zirconium bromide. The ratio of powers (X/Y) is 1. A gas mixture composed of argon and nitrogen (10 vol.%) is simultaneously injected, during the deposition of nanostructured composite material on the titanium nitride layer. A polarization tension of -300 V is applied in the cathodic sputtering enclosure.