TY - GEN
T1 - Thermodynamics and friction mechanism analysis of DLC films on H13 steel under high Temperature
AU - Zeng, Qunfeng
AU - Eryilmaz, Osman
AU - Dong, Guangneng
AU - Luo, Li
N1 - Publisher Copyright:
Copyright © (2013) by Politecnico di Torino (DIMEAS) All rights reserved.
PY - 2013
Y1 - 2013
N2 - Diamond like carbon (DLC) films combine high hardness with exceptional tribological properties. They can afford super low friction and high wear-resistance under dry lubrication. The tribological properties of DLC films on HI3 steel substrate were investigated in open air environment under high temperature up to 500 °C. Raman spectroscopy and optical microscopy were used to measure the structural changes of DLC films and observe wear scar on the worn surface under different test temperatures, respectively. The experimental results showed that average coefficient of friction (COF) of DLC films decreased from 0.067 to 0.018 with the increase of temperature below 300 °C (from 100°C to 200 °C), however, average COF increased to 0.376, 0.228 and 0.539 at the temperature of 300 °C, 400 °C and 500 °C, respectively. In order to understand the friction mechanism, we have studied their evolution in the tribological system by the film structure on the worn surface. It was found that there are the film graphitization and oxidization phenomena generated during the friction test process as measured by Raman spectroscopy. So, it is needed to know the reaction dynamic mechanism of DLC films on the steel substrate in open air and apply it the real tribological system. The thermodynamics analysis of DLC films on steel under high temperature in open air was discussed according to its tribochemistry reaction. And Fe/O2 system under high temperature is also calculated by using thermodynamic method in order to reflect the real tribological system. The possible friction mechanism of DLC films at elevated temperature is graphitization and oxidization. Under low temperature, the graphitization of DLC films is beneficial to their low friction. With increase of temperature, there is oxidation occurring at the contact surface, Fe3O4 is the main product on the worn surface at 300 °C and 400 °C, and as temperature increasing to 500 °C, α-Fe2O3 starts to generate and becomes the main product.
AB - Diamond like carbon (DLC) films combine high hardness with exceptional tribological properties. They can afford super low friction and high wear-resistance under dry lubrication. The tribological properties of DLC films on HI3 steel substrate were investigated in open air environment under high temperature up to 500 °C. Raman spectroscopy and optical microscopy were used to measure the structural changes of DLC films and observe wear scar on the worn surface under different test temperatures, respectively. The experimental results showed that average coefficient of friction (COF) of DLC films decreased from 0.067 to 0.018 with the increase of temperature below 300 °C (from 100°C to 200 °C), however, average COF increased to 0.376, 0.228 and 0.539 at the temperature of 300 °C, 400 °C and 500 °C, respectively. In order to understand the friction mechanism, we have studied their evolution in the tribological system by the film structure on the worn surface. It was found that there are the film graphitization and oxidization phenomena generated during the friction test process as measured by Raman spectroscopy. So, it is needed to know the reaction dynamic mechanism of DLC films on the steel substrate in open air and apply it the real tribological system. The thermodynamics analysis of DLC films on steel under high temperature in open air was discussed according to its tribochemistry reaction. And Fe/O2 system under high temperature is also calculated by using thermodynamic method in order to reflect the real tribological system. The possible friction mechanism of DLC films at elevated temperature is graphitization and oxidization. Under low temperature, the graphitization of DLC films is beneficial to their low friction. With increase of temperature, there is oxidation occurring at the contact surface, Fe3O4 is the main product on the worn surface at 300 °C and 400 °C, and as temperature increasing to 500 °C, α-Fe2O3 starts to generate and becomes the main product.
KW - Diamond like carbon films
KW - Graphitization
KW - Oxidation
KW - Thermodynamics
KW - Tribological properties under high temperature
UR - https://www.scopus.com/pages/publications/84919415462
M3 - 会议稿件
AN - SCOPUS:84919415462
T3 - 5th World Tribology Congress, WTC 2013
SP - 696
EP - 702
BT - 5th World Tribology Congress, WTC 2013
PB - Politecnico di Torino (DIMEAS)
T2 - 5th World Tribology Congress, WTC 2013
Y2 - 8 September 2013 through 13 September 2013
ER -