RESEARCH OF WEAR RESISTANCE OF CHROME DIAMOND COATING

At a Glance

Metadata	Details
Publication Date	2020-01-01
Journal	Metal …
Authors	Julia Averina, Galina Kalyakina, В. С. Болдырев, А. Г. Чередниченко, Evgenia Rybina
Institutions	Peoples’ Friendship University of Russia, Bauman Moscow State Technical University
Citations	1
Analysis	Full AI Review Included

Technical Documentation & Analysis: Diamond Composite Coatings

Executive Summary

This research validates the significant performance enhancement achieved by incorporating nanodiamond (ND) particles into conventional hard chromium plating, demonstrating a powerful application for diamond materials in surface engineering.

Core Value Proposition: Nanodiamond-chromium (ND-Cr) composite coatings significantly improve the physicomechanical indices of hard chromium plating, leveraging diamond’s intrinsic superhardness and low friction coefficient.
Performance Achievement: The composite coating demonstrated a non-porous structure, ensuring high corrosion resistance, and achieved microhardness values up to 328.4 MPa (HV0.2) in the tested samples.
Wear Resistance: The use of ND particles resulted in a substantial increase in the service life of tools and friction parts, ranging from 2 to 15 times compared to standard chromium plating.
Surface Quality: The coatings exhibited excellent surface quality, achieving high gloss values (up to 74 GU at 20°) and low wear rates (minimum 30 mg weight loss over 5000 Taber cycles).
Methodology: The coatings were produced via electroplating, utilizing the coprecipitation of nanosized diamond particles with chromium.
6CCVD Relevance: This study confirms the critical need for high-performance diamond materials in extreme wear and friction applications, directly aligning with 6CCVD’s expertise in bulk MPCVD Single Crystal Diamond (SCD) and Polycrystalline Diamond (PCD) solutions.

Technical Specifications

Parameter	Value	Unit	Context
Coating Thickness (Range)	11.852 to 46.340	µm	Measured samples (Table 1)
Microhardness (HV0.2)	318.9 to 328.4	MPa	Measured values for 11.852 µm and 22.020 µm coatings
Potential Microhardness	Up to 1000	MPa	Cited potential for ND-Cr coatings [4]
Service Life Improvement	2 - 15	times	Compared to conventional hard chromium plating
Wear Test Load	500	g	Taber rotational abrasimeter standard
Wear Test Cycles	5000	cycles	Taber rotational abrasimeter standard
Minimum Weight Loss	30	mg	Sample 2 (22.020 µm thickness)
Maximum Gloss Value	74	GU	Sample 3 (Measured at 20° angle)
Vickers Pyramid Apex Angle	136	°	Standard for Vickers microhardness testing

Key Methodologies

The study focused on characterizing the physical and mechanical properties of the chromium-diamond composite coating using established metrology standards.

Coating Preparation: The chromium-diamond coating was deposited via electroplating, utilizing the coprecipitation of nanosized diamond particles with hexavalent chromium.
Thickness Measurement: Coating thickness was precisely determined using an OLYMPUS LEXT OLS4100 confocal laser scanning microscope.
Porosity Testing: The filter paper method was employed, utilizing Solution 32 (Potassium iron-hydrogen-3 g/dm³; Sodium chloride-10 g/dm³) applied for 5 minutes to confirm the non-porous nature of the coating.
Microhardness Determination: The Vickers method (HV0.2) was used. A 136° tetrahedral diamond pyramid was pressed into the sample surface under a 0.5 kg load for 10-15 seconds.
Wear Resistance Testing: A Taber rotational abrasimeter was used. Samples were subjected to abrasive wheels under a 500 g load at 60 rpm for 5000 cycles. Wear resistance was quantified by measuring weight loss (mg).
Gloss Measurement: A gloss meter was used to measure the reflection coefficient at a 20° angle (suitable for mirror sheen surfaces), yielding results in Gloss Units (GU).

6CCVD Solutions & Capabilities

This research highlights the superior performance derived from diamond’s intrinsic properties—superhardness, chemical inertness, and low friction. While the paper uses nanodiamond powder as an additive, 6CCVD specializes in manufacturing bulk, high-ppurity MPCVD diamond materials, offering solutions that exceed the performance limits of composite coatings for critical applications.

Applicable Materials

To replicate or extend the performance characteristics demonstrated in this research, 6CCVD recommends the following materials:

Mechanical Grade Polycrystalline Diamond (PCD): Ideal for large-area wear plates, friction units, and high-throughput tooling where maximum abrasion resistance is required. 6CCVD offers PCD plates up to 125 mm in diameter.
Optical Grade Single Crystal Diamond (SCD): Recommended for applications requiring the highest purity, thermal conductivity, and ultra-low friction surfaces (Ra < 1 nm). Perfect for high-precision bearings or heat spreaders in extreme environments.
Boron-Doped Diamond (BDD): For electrochemical applications or sensors where the inertness and hardness of diamond must be combined with metallic conductivity.

Customization Potential

6CCVD’s advanced manufacturing capabilities allow engineers to move beyond thin composite layers to robust, application-specific diamond components.

Research Requirement / Application	6CCVD Capability	Specification Advantage
Wear Layer Thickness	Custom SCD/PCD Thickness	We provide SCD and PCD layers from 0.1 µm up to 500 µm, allowing for wear layers significantly thicker and more robust than typical electroplated coatings (e.g., 46 µm in the study).
Surface Finish & Friction	Ultra-Precision Polishing	For critical friction units, we guarantee surface roughness Ra < 1 nm (SCD) and Ra < 5 nm (Inch-size PCD), minimizing friction far beyond the capabilities of the tested composite coating.
Component Integration	In-House Metalization	We offer custom metalization (Au, Pt, Pd, Ti, W, Cu) for bonding, electrical contact, or integration into complex mechanical assemblies, ensuring seamless device manufacturing.
Large Area Coverage	Large Format PCD Wafers	We supply PCD wafers up to 125 mm in diameter, suitable for large-scale industrial wear plates and tooling.

Engineering Support

The 6CCVD in-house PhD team specializes in translating performance requirements for extreme environments (high wear, high temperature, chemical inertness) into optimal diamond material specifications. We offer consultation on:

Selecting the appropriate diamond morphology (SCD vs. PCD) based on required hardness and thermal management.
Designing custom metalization schemes for robust bonding in high-stress friction units.
Optimizing material thickness and surface finish for specific abrasive wear and friction unit projects, ensuring maximum service life extension.

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

View Original Abstract

Chrome plating is widely used as a protective and decorative coating and to increase the wear resistance of measuring and cutting tools.To improve the properties of the chrome coating, nanosized particles are coprecipitated with it.Since nanodiamond particles possess the properties of diamond, that is, superhardness, low coefficient of friction, high thermal conductivity and chemical inertness, they are used precisely during deposition with chromium.This article presents a study of chromium-diamond coating.Determination of its wear resistance, microhardness, porosity and other indicators.The use of chromium-diamond coating allows to improve to a greater extent the physicomechanical indices of hard chromium plating, as well as to increase corrosion resistance and increase the service life of parts operating under conditions of corrosion wear.

Tech Support

Original Source

DOI: https://doi.org/10.37904/metal.2020.3556