Development of gas turbine oils that can be used in higher temperature conditions remains the greatest technological challenge. Though the maximum operating temperature of conventional lubricating oils is generally se...Development of gas turbine oils that can be used in higher temperature conditions remains the greatest technological challenge. Though the maximum operating temperature of conventional lubricating oils is generally set around 100 ℃, or 140 ℃ for scavenged oils, it is predicted that the future will require oils to function at 200 ℃ or above. To find a clue to developing oils that can be used at higher temperatures, this study attempted to estimate service lives and operating temperature ranges of certain oils, including oils conforming to MIL-PRF-23699, which are deemed promising candidates for high-temperature applications, by analyzing their reaction rates of degradation and degeneration by oxidation. Among a number of methods used in the analyses of reaction rates, this study chose thermo-gravimetry （TG）, with which estimations can be made relatively easily.展开更多
Comparative molecular field analysis and comparative molecular similarity indices analysis were employed to analyze the antiwear properties of a series of 57 esters as potential lubricant-based oils. Predictive 3D-qua...Comparative molecular field analysis and comparative molecular similarity indices analysis were employed to analyze the antiwear properties of a series of 57 esters as potential lubricant-based oils. Predictive 3D-quantitative structure tribo-ability relationship models were established using the SYBYL multifit molecular alignment rule with a training set and a test set. The optimum models were all shown to be statistically significant with cross-validated coefficients q^2 > 0.5 and conventional coefficients r^2 > 0.9, indicating that the models are sufficiently reliable for activity prediction, and may be useful in the design of novel ester-based oils.展开更多
For environmental protection, energy conservation, and other reasons, water-based lubricants are increasingly chosen to replace oil lubricants. Water-based lubricants are divided into emulsified and solution types. So...For environmental protection, energy conservation, and other reasons, water-based lubricants are increasingly chosen to replace oil lubricants. Water-based lubricants are divided into emulsified and solution types. Solution type water-based lubricants have attracted significant attention for the good stability, easy biodegradability, and safety for workers. However, some problems exist with current solution type water-based lubricants, such as poor lubricity and corrosion resistance. During the cold-rolling process, A1 plate rolled using oil-based lubricant lubrication shows metallic luster, but that rolled using water-based lubricant shows corrosion spots, black strips, and no metallic luster. Therefore, this study mainly analyzed the reasons for the darkness of A1 plate cold-rolled with water solution lubricants. The differences in plate surfaces lubricated by water solution and oil were investigated by scanning electron microscopy, auger electron spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. The analysis results showed that the surface of the oil-lubricated sample is smooth, the oxygen content is low, and the oxide layer is thin, while the surface of the water solution-lubricated sample is rough, the oxygen content is high, the chemical composition is more complex, and the oxide layer is not uniform and thick.展开更多
文摘Development of gas turbine oils that can be used in higher temperature conditions remains the greatest technological challenge. Though the maximum operating temperature of conventional lubricating oils is generally set around 100 ℃, or 140 ℃ for scavenged oils, it is predicted that the future will require oils to function at 200 ℃ or above. To find a clue to developing oils that can be used at higher temperatures, this study attempted to estimate service lives and operating temperature ranges of certain oils, including oils conforming to MIL-PRF-23699, which are deemed promising candidates for high-temperature applications, by analyzing their reaction rates of degradation and degeneration by oxidation. Among a number of methods used in the analyses of reaction rates, this study chose thermo-gravimetry （TG）, with which estimations can be made relatively easily.
基金supported by the National Nature Science Foundation of China (NSFC, No. 51675395)
文摘Comparative molecular field analysis and comparative molecular similarity indices analysis were employed to analyze the antiwear properties of a series of 57 esters as potential lubricant-based oils. Predictive 3D-quantitative structure tribo-ability relationship models were established using the SYBYL multifit molecular alignment rule with a training set and a test set. The optimum models were all shown to be statistically significant with cross-validated coefficients q^2 > 0.5 and conventional coefficients r^2 > 0.9, indicating that the models are sufficiently reliable for activity prediction, and may be useful in the design of novel ester-based oils.
基金supported by the National Key Basic Research Program of China(Grant No.2013CB934200)the National Natural Science Foundation of China(Grant Nos.51335005&51527901)
文摘For environmental protection, energy conservation, and other reasons, water-based lubricants are increasingly chosen to replace oil lubricants. Water-based lubricants are divided into emulsified and solution types. Solution type water-based lubricants have attracted significant attention for the good stability, easy biodegradability, and safety for workers. However, some problems exist with current solution type water-based lubricants, such as poor lubricity and corrosion resistance. During the cold-rolling process, A1 plate rolled using oil-based lubricant lubrication shows metallic luster, but that rolled using water-based lubricant shows corrosion spots, black strips, and no metallic luster. Therefore, this study mainly analyzed the reasons for the darkness of A1 plate cold-rolled with water solution lubricants. The differences in plate surfaces lubricated by water solution and oil were investigated by scanning electron microscopy, auger electron spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. The analysis results showed that the surface of the oil-lubricated sample is smooth, the oxygen content is low, and the oxide layer is thin, while the surface of the water solution-lubricated sample is rough, the oxygen content is high, the chemical composition is more complex, and the oxide layer is not uniform and thick.
