High Energy Radial Deposition of Diamond-Like Carbon Coatings

At a Glance

Metadata	Details
Publication Date	2015-07-24
Journal	Coatings
Authors	Konrad Suschke, René Hübner, Peter P. Murmu, Prasanth Gupta, J. Futter
Institutions	GNS Science, MacDiarmid Institute for Advanced Materials and Nanotechnology
Citations	13
Analysis	Full AI Review Included

Technical Analysis and Sales Documentation: High Energy Radial Deposition of Diamond-Like Carbon Coatings

Documentation Prepared for 6CCVD Engineering and Sales Teams. Reference: Coatings 2015, 5, 326-337; doi:10.3390/coatings5030326

Executive Summary

This research investigates the direct ion deposition of high-energy Diamond-Like Carbon (DLC) coatings using a novel 360° Circular Anode Layer Ion Source (CALIS). The core findings establish a reproducible method for producing highly adherent, micron-thick DLC layers suitable for industrial applications like inner wall pipe coating.

Novel Deposition System: Utilizes a custom 360° radial direct ion source (CALIS) capable of coating conductive and semi-insulating inner pipe surfaces (up to 150 mm diameter tested).
Process Parameters: DLC films were synthesized using Butane (C4H10) precursor gas, with total acceleration voltages ranging from 4 kV to 8 kV and a stable ion current of 10 mA.
Three-Layered Structure: Cross-sectional TEM revealed a distinct three-layered structure, comprising an initial impurity-rich adhesion layer (Type I), a thick amorphous middle layer (Type II), and a final impurity-rich surface layer (Type III).
Structural Tailoring: The unique layer structure and composition are directly influenced by dynamic deposition parameters: ion source movement (1.5 mm h-1), ion current density, deposition angle, and sputtering effects.
Material Quality: Coatings exhibit excellent mechanical properties, including high hardness (>20 GPa, estimated via Raman G-FWHM of 160-170) and low friction (AFM roughness < 50 nm).
Growth Model: The layered growth suggests a continuous sandwich structure formed by overlapping perpendicular (Type II) and wide-angle non-perpendicular (Type III) deposition stages as the source moves.

Technical Specifications

The following parameters summarize the key experimental and material data extracted from the study on High Energy Radial Deposition of DLC coatings:

Parameter	Value	Unit	Context
Precursor Gas	Butane (C<sub>4</sub>H<sub>10</sub>)	N/A	Carbon source for DLC coating.
Anode Voltage (Bias)	1.5	kV	Potential difference maintained within the source.
Total Acceleration Voltage	4 to 8	kV	Used to control ion impact energy and film structure.
Target Ion Current	10	mA	Constant current maintained under high vacuum.
Operational Pressure Range	10<sup>-5</sup>	hPa	High vacuum range required for direct ion deposition.
Deposition Rate (Peak)	65 ± 5	nm min<sup>-1</sup>	Measured in the narrow, central deposition region.
Ion Source Travel Speed	1.5	mm h<sup>-1</sup>	Speed used to ensure uniform 3 µm thickness.
Nominal Coating Thickness	3 to 4	µm	Uniform thickness achieved across long lengths.
Hardness (Estimated)	>20	GPa	Indicative of high sp<sup>3</sup> content (DLC).
Raman G-FWHM	160-170	N/A	Full Width Half Maximum (indicator of hardness/sp<sup>3</sup> content).
Surface Roughness (Ra)	< 50	nm	Measured using Atomic Force Microscopy (AFM).
Coating sp<sup>2</sup>:sp<sup>3</sup> Ratio	3:1	N/A	Proportion determined by sub-plantation model.

Key Methodologies

The experimental design utilizes a specialized setup for dynamic, radial ion deposition, followed by detailed structural analysis.

Circular Anode Layer Ion Source (CALIS): A novel 360° ion source was employed, consisting of an anode and cathode, powered by a single high voltage supply and confined by permanent magnets.
Precursor and Substrates: Butane gas was used as the carbon precursor. Substrates included Silicon <100> wafers and stainless steel sections placed inside a 150 mm diameter pipe.
Dynamic Deposition: The CALIS source was moved along the pipe center at a constant speed (1.5 mm h-1) to create laterally homogeneous, thick coatings by overlapping deposition profiles.
Thickness Measurement: SLOAN Dektak Profilometry was used to determine deposition profiles and final coating thickness, achieving an accuracy of ±10 nm.
Cross-Sectional Analysis (TEM/FIB): Samples were prepared using Focused Ion Beam (FIB, utilizing Ga+ ions and a Pt protective layer) to create thin lamellae (0.1 nm point resolution) for Transmission Electron Microscopy (TEM).
Elemental Analysis (EDX): Energy Dispersive X-ray Spectroscopy (EDX) was performed across the coating cross-sections and interfaces to identify elemental composition (C, Si, Fe, Cr, Cl, S) and track impurity incorporation.
Structural Confirmation: Fourier transformation of TEM images confirmed localized hexagonal nanocrystalline structure within the amorphous DLC, exhibiting a lattice spacing of 150 pm.

6CCVD Solutions & Capabilities

The research demonstrates the technical feasibility of producing tailored, high-performance carbon films for challenging industrial applications, such as internal pipe surfaces. While this paper focuses on amorphous DLC, 6CCVD specializes in the highest quality, synthetic Crystalline Diamond (SCD/PCD/BDD), which serves as the ultimate benchmark for hardness, thermal management, and electrochemical functionality in related engineering projects.

Applicable Materials for Replication and Extension

To replicate the high-energy material interfaces studied here, or to advance the application into areas requiring high purity, extreme hardness, or conductive properties, 6CCVD offers specialized CVD diamond materials:

6CCVD Material	Suggested Application Context	Rationale
High Modulus PCD	Large-Area Mechanical Benchmarking	Used as a substrate or comparison material requiring ultimate hardness and stiffness over areas up to 125mm.
Optical Grade SCD	High-Purity Interface Studies	Single Crystal Diamond (SCD) provides a non-contaminating, thermally stable substrate ideal for analyzing DLC adhesion mechanisms without substrate interference (unlike Si or Steel).
Heavy Boron-Doped (BDD)	Advanced Electrochemical/Sensor Applications	If the DLC pipe coatings are intended for sensing (as referenced in related work [7]), BDD wafers offer the highest conductivity, stability, and corrosion resistance for benchmarking electrode performance.

Customization Potential for Engineering Success

The precision required in the DLC study—handling micron-scale films and analyzing specific interface metalization—is directly supported by 6CCVD’s core engineering services:

Precision Thickness Control: The paper’s DLC coatings were 3-4 µm thick. 6CCVD supplies thin film SCD and PCD starting from 0.1 µm up to 500 µm, allowing researchers to test materials across the full spectrum from true 3D crystal to thin film integration.
Custom Dimensions and Machining: The CALIS source was designed for 150 mm pipes. 6CCVD provides PCD plates/wafers up to 125 mm, which can be custom-cut (via laser machining) to fit unique geometries or standardized component carriers needed for advanced testing rigs.
Interface Engineering (Metalization): The TEM analysis required a Pt protection layer. 6CCVD possesses internal metalization capabilities (Au, Pt, Pd, Ti, W, Cu), enabling clients to order pre-coated diamond substrates tailored for specific electrical contacts, adhesion layers, or bonding requirements (e.g., Ti/Pt/Au stacks).
Ultra-Smooth Polishing: While DLC achieved Ra < 50 nm, 6CCVD achieves ultra-smooth surfaces critical for high-resolution analysis: Ra < 1 nm (SCD) and Ra < 5 nm (Inch-size PCD), ideal for subsequent deposition or direct measurement interfaces.

Engineering Support & Global Logistics

6CCVD’s in-house PhD team can assist with material selection for similar Advanced Functional Coating projects, ensuring the optimum balance of crystal quality, doping, and surface preparation for both fundamental research and industrial scale-up.

We offer reliable Global Shipping (DDU default, DDP available) to ensure your high-value CVD diamond materials arrive promptly and securely, regardless of your laboratory location.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

Diamond-like carbon (DLC) coatings were deposited with a new direct ion deposition system using a novel 360 degree ion source operating at acceleration voltage between 4 and 8 kV. Cross-sectional TEM images show that the coatings have a three layered structure which originates from changes in the deposition parameters taking into account ion source condition, ion current density, deposition angles, ion sputtering and ion source movement. Varying structural growth conditions can be achieved by tailoring the deposition parameters. The coatings show good promise for industrial use due to their high hardness, low friction and excellent adhesion to the surface of the samples.

Tech Support

Original Source

DOI: https://doi.org/10.3390/coatings5030326

References

2006 - Tribology of diamond-like carbon films: Recent progress and future prospects [Crossref]
2004 - Cutting performance of DLC coated tools in dry machining aluminum alloys [Crossref]
2004 - Nanocrystalline diamond-like carbon coatings produced on the Si3N4-TiC composites intended for the edges of cutting tools [Crossref]
2007 - Diamond-like carbon for data and beer storage [Crossref]
2014 - History of diamond-like carbon films—From first experiments to worldwide applications [Crossref]
1999 - Structural and mechanical properties of diamond-like carbon films prepared by pulsed laser deposition with varying laser intensity [Crossref]
1999 - Mechanical properties of diamond-like carbon composite thin films prepared by pulsed laser deposition [Crossref]
2004 - Raman spectroscopy of amorphous, nanostructured, diamond-like carbon, and nanodiamond [Crossref]