Технологія і техніка друкарства (Sep 2018)
Thermodynamic Analysis of the Interaction of High-speed Composites of Printing Machines Based on Nickel with Oxygen
Abstract
The article analyzes the oxidation processes in the friction film on the surface of antifriction composite based on the powder nickel alloy EP975 with solid lubricant CaF2 in air at high rotational speeds or temperatures which occur on contact surfaces. This composite had been developed to equip units of high-speed printing machines which operate at severe exploitation conditions. The oxidation processes were studied by analyzing the interaction of composite with air by means of thermodynamic analysis. The thermodynamic analysis method description has been presented in the article. The article shows the results of the thermodynamic simulation the interaction of the researched antifriction composite with air at high temperatures using the ASTRA.4 program. The simulation results were compared with the experimental data. It has been shown the friction film contains solid lubricant and oxides of the composite’s alloying elements. The composite’s functional properties level depends on the quantitative ratio of the formed oxides in combination with CaF2 in the friction film at high rotational speeds or operating temperatures. Thermodynamic computer modeling of the interaction of air with individual elements and reinforcing compounds, in the investigated composite allows calculation of the composition of the condensed and gas-vapor phases, over a wide range of temperatures. The positive results of this research allow us to recommend new composite materials on the basis of nickel, for difficult conditions of working friction units of high-speed printing machines. Further research will focus on determining the quantity of oxide phases in the friction films and their effect on the tribotechnical properties of the composite at different temperature conditions for high-speed printing equipments.
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