Diamond Nanocrystals via Tribosynthesis
Conversion of Amorphous Carbon, Suspended in Oil, to Nano-Size Diamond Crystallites via Tribosynthesis Improving Endurance of High-Loaded Wearing Surfaces
Tech Area / Field
- MAT-SYN/Materials Synthesis and Processing/Materials
- MAN-TRI/Tribology/Manufacturing Technology
3 Approved without Funding
Georgian Technical University, Georgia, Tbilisi
- University of Dayton, USA, OH, Dayton\nTokyo Institute of Technology / Graduate School of Science and Engineering, Japan, Tokyo
Project summaryThe objective of the project is to develop new remedies for increasing the wearing capacity of heavy loaded parts in automobiles and tractors. Up to date progress towards reducing wear rates and associated improved performance of transmission components has been in either one of two areas: advanced materials or lubrication/additives science. The proposed project focuses on advanced surface and oil/additives system. The study is focused towards understanding the interaction between the surface and the lubricant constituents that will result in considerable improvement in wear and friction performance. Our previous works in this direction showed that during metallic friction of the surfaces of rubbing components, in the environment of oil, containing highly dispersed amorphous carbon, the diamond nanocrystals are growing. The latter increases the microhardness and heat conductivity while the friction coefficient is reduced. Diamond crystallites were also observed after irradiation of metallic surface, coated by the highly dispersed composite containing amorphous carbon, with laser beam.
In the proposed project we intend to develop a new method for increasing the wear resistance of friction components (especially of heavy-loaded ones), by means of conversion of the suspended in the oil fine fraction of amorphous carbon to a hetero-phase film with the inclusions of diamond nanocrystals on the rubbing surfaces.
Another goal of the project is to investigate the processing parameters that influence the nucleation of diamond nanocrystals on metallic surfaces during friction and irradiation with the laser beam over a fine amorphous carbon. The mechanism of diamond nanocrystals synthesis and its modifications will be studied, and the optimal parameters of laser beam, technological modes and carbon containing composites will also established in order to obtain high-level tribological properties of the rubbing surfaces
Scientific value of the project is that the regularities of the diamond nanocrystals’ tribosynthesis phenomenon will be studied. The scientific merit of the proposed project is focused on the possibility of obtaining a new composition for transmission oil and determine the diamond growth mechanisms of formation of crystallites in oil tribosynthesis.
Practical and commercial value of the project is the possibility of production of highly-efficient low-cost lubricating materials with the fine amorphous carbon additives, in order to substantially reduce friction and wear of heavy-loaded mechanisms.
The technical merit of the project includes a design of special technology for production of transmission oil for high-loaded gears, car bearings and other machines that will provide increase in tribological, low temperature and conservation properties of the oil. The technology provides high colloid stability and increases performance duration within the wide range of conditions. In order to improve the tribological parameters, the following tasks are planned to be implemented in frames of the proposed project:
– TEM, SEM, X-ray and Auger-spectroscopy study of fractal structure of the amorphous carbon, coatings and diamond-structured carbon crystallites;
– High-energy electron diffraction study of the surfaces formed via tribosynthesis;
– Parametrization of fractals of the amorphous carbon;
– Determination of hydrodynamic and tribological parameters of the oils with the special additives;
– Determination of factors influencing creation of the crystallites of diamond;
– Determination of the optimal parameters of the rubbing surface and composition of the additives.
Validity of the expected results is provided by the experience and knowledge of Georgian scientific team participating in this project. This knowledge was accumulated by the participation in several several defense projects, conducting fundamental and applied research in the field of materials science and development of a high-performance oils and lubricants for heavy-loaded machines. In addition it can be noted that most of the participants have taken part in fundamental research projects including state projects implemented in the former USSR, such as “Space Physics of Metals” program.