[P1-74] Designing Lubricant Additives for Titanium Carbide Surface: First-principles and Molecular Dynamics Investigations
In order to highly improving performance of industrial products such as automobile, the innovative technology should be strongly required, especially for the fields of surface and interface technology. Several problems on surface fractures, i.e. fatigue, wear, corrosion and erosion have been arisen in a metallic bearing or gear which typically work under the conditions of high temperature, extreme pressure and shear.
One of the technologies for reducing surface fractures is a hard coating on surface. For example, in the field of tribology, diamond-like carbon (DLC) coatings have been strenuously investigated so far. Covering surface with the film leads to low friction and low wear performances, contributing to extending a product lifetime and to reducing a maintenance work of products. However, under the lubrication by engine oil, DLC coating unexpectedly caused wear. This negative effect may be due to existence of organic molybdenum compounds in engine oil as a friction modifier. A novel additive compound has been developed by modifying adsorption property. This story tells us that tailor-made additives have to be required for own hard coating applied to shear parts.
Titanium-based hard coatings are also forcused for extending lifetime of products. Especially, titanium carbides show extremely high hardness and coincidently have anti-wear, anti-corrosion, and anti-oxidant properties. This material has been applied to cutting tools used at high temperature, extreme pressure and shear. Hence, titanium carbide seems to be a suitable surface coating material for extending lifetime.
In the present study reported here, for the purpose of extending lifetime of industrial products, a chemical composition of lubricant oil was optimized for titanium carbide coatings. An optimum molecular structure of additive compounds and its interaction with titanium carbide were theoretically investigated by using a method of density functional theory (DFT). An adsorption energy on TiC(100) was calculated for several additive compounds. The simulation results showed that the amide-type molecule showed high adsorption energy, suggesting that these additives would exhibit a good lubrication performance.
One of the technologies for reducing surface fractures is a hard coating on surface. For example, in the field of tribology, diamond-like carbon (DLC) coatings have been strenuously investigated so far. Covering surface with the film leads to low friction and low wear performances, contributing to extending a product lifetime and to reducing a maintenance work of products. However, under the lubrication by engine oil, DLC coating unexpectedly caused wear. This negative effect may be due to existence of organic molybdenum compounds in engine oil as a friction modifier. A novel additive compound has been developed by modifying adsorption property. This story tells us that tailor-made additives have to be required for own hard coating applied to shear parts.
Titanium-based hard coatings are also forcused for extending lifetime of products. Especially, titanium carbides show extremely high hardness and coincidently have anti-wear, anti-corrosion, and anti-oxidant properties. This material has been applied to cutting tools used at high temperature, extreme pressure and shear. Hence, titanium carbide seems to be a suitable surface coating material for extending lifetime.
In the present study reported here, for the purpose of extending lifetime of industrial products, a chemical composition of lubricant oil was optimized for titanium carbide coatings. An optimum molecular structure of additive compounds and its interaction with titanium carbide were theoretically investigated by using a method of density functional theory (DFT). An adsorption energy on TiC(100) was calculated for several additive compounds. The simulation results showed that the amide-type molecule showed high adsorption energy, suggesting that these additives would exhibit a good lubrication performance.