Manufacture and characterization of Boron Oxide solid lubricant using RF

magnetron sputtering at low-vacuumCharacterization of boron based coatings on Silicon substrate, the manufacturing issues

arising form boron coating manufacturing, and noble solutions to resolving the problems.

Introduction

Coating Technology– Metal Coatings– Diamond-like carbon

(DLC)– Boron Coatings

Manufacturing methods– Chemical Vapor

Deposition– Electroplating– Radio Frequency

Magnetic Sputtering

Boron Coatings

• Types– Boron Oxides– Boron Nitrides

• Hexagonal BN• Cubic BN

– Boron Carbide– Boron nitrogen carbon

(BNC)• Advantages– Thermal Stability– Chemical Stability

Radio Frequency Magnetic Sputtering

• Advantages– High-melting Point

Materials– Top-down

manufacturing– Low maintenance– High adhesion– High reproducibility

Initial Idea

• Boron Coatings– Clear advantages over

DLC coatings– Very little fundamental

research– Possible compatibility

with carbon for hybrid coating systems

• Applications– Steel/Iron based tooling– High-temperature

Applications– Possible use as a

intermediate layer for DLC applications

Problems Encountered

• Reproducibility• Control of environment• Manufacturing

parameters• Measurement of

manufacturing variables• Boron coating chemical

stability• Residual stresses

Applied Solutions

• Multiple-layer manufacturing

• Extra measurement equipment

• Addition of Carbon interlayer

Manufactured FilmsFilms manufactured had a variety of different possible modifiers. As such, it was decided on the following manufacturing vectors:– Gas composition– Pressure– Distance– Substrate Bias– Self-Bias– Interlayer– Multi-layer application

Methods of Characterization

• Friction Test• Profilometry• Raman Spectroscopy• Scanning Electron

Microscopy (SEM)• Auger Electron

Spectroscopy (AES)

Physical Characteristics

• Reactivity with atmosphere

• Low material strength• High wear rate• Small friction coefficient

reduction• Interesting optical

characteristics– Fluorescence

• High impurity content

Conclusion

• Reduction of residual stresses by multi-layer application

• Ease of manufacture by established methods• Possibility of manufacturing and modifying

desired molecular structure

Further Work

• Establishing explanation for optical properties

• Modifying manufacturing method to reduce impurities

• Testing in high pressure and high temperature environments

• Testing on steel/iron substrates

• Optimization of manufacturing parameters

• Development of BNC coating and characterization

• Determining density of coatings

References

Images:– http://www.polymedia.ch/OpArticles/view/57

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