The pure molybdenum sheet and the Al2O3-doped molybdenum alloy sheets were prepared by the hydrothermal method and a subsequent powder metallurgy process. The effects of Al2O3particles addition on the recrystallizatio...The pure molybdenum sheet and the Al2O3-doped molybdenum alloy sheets were prepared by the hydrothermal method and a subsequent powder metallurgy process. The effects of Al2O3particles addition on the recrystallization temperature, microstructures and properties of the Mo sheets were investigated as the focus. The Al2O3-doped Mo sheets have greater strength than the pure Mo sheet, and the 0.50 wt% Al2O3-doped Mo sheet has the best performance. For the unannealed specimens, the strength increases with the increase in Al2O3content.Compared with that of pure Mo sheet, the strength of0.50 wt% Al2O3-doped Mo sheet increases by 72%, 54%,73% and 76%, respectively, when annealed at 1000,1100,1200 and 1300 ℃, which is a very obvious reinforcement effect. When lower than 1100 ℃, the elongation of the pure Mo sheet is the best. However, when the annealing temperature is equal to or greater than 1100 ℃,the 0.50 wt% Al2O3-doped Mo sheet obtains the best elongation. Moreover, the Al2O3addition can greatly improve the recrystallization temperature of molybdenum sheets; for example, the recrystallization temperature of the0.50 wt% Al2O3-doped Mo sheet increases by 200 ℃ at least than that of the pure Mo sheet. Lastly, the strengthening mechanism was discussed.展开更多
The NiCrAlY-Mo-Ag composite coatings were prepared by atmospheric plasma spraying. The tribological properties of the composite coatings were investigated from 25 to 900 ℃ in details. The tribo-layer formed on the wo...The NiCrAlY-Mo-Ag composite coatings were prepared by atmospheric plasma spraying. The tribological properties of the composite coatings were investigated from 25 to 900 ℃ in details. The tribo-layer formed on the worn surface of the composite coatings and influenced the tribological properties at different temperatures. The addition of silver could effectively decrease the friction coefficient and wear rate of the coatings at the wide range of temperature. The rubbing process could form the nickel molybdate and promote the formation of silver molybdate within the worn surfaces at high temperature. The synergistic lubricating effects of nickel molybdate and silver molybdate are attributed to the improvement of the tribological properties of coatings at high temperature.展开更多
基金financially supported by the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT1234)the National Natural Science Foundation of China (No. 50972039)
文摘The pure molybdenum sheet and the Al2O3-doped molybdenum alloy sheets were prepared by the hydrothermal method and a subsequent powder metallurgy process. The effects of Al2O3particles addition on the recrystallization temperature, microstructures and properties of the Mo sheets were investigated as the focus. The Al2O3-doped Mo sheets have greater strength than the pure Mo sheet, and the 0.50 wt% Al2O3-doped Mo sheet has the best performance. For the unannealed specimens, the strength increases with the increase in Al2O3content.Compared with that of pure Mo sheet, the strength of0.50 wt% Al2O3-doped Mo sheet increases by 72%, 54%,73% and 76%, respectively, when annealed at 1000,1100,1200 and 1300 ℃, which is a very obvious reinforcement effect. When lower than 1100 ℃, the elongation of the pure Mo sheet is the best. However, when the annealing temperature is equal to or greater than 1100 ℃,the 0.50 wt% Al2O3-doped Mo sheet obtains the best elongation. Moreover, the Al2O3addition can greatly improve the recrystallization temperature of molybdenum sheets; for example, the recrystallization temperature of the0.50 wt% Al2O3-doped Mo sheet increases by 200 ℃ at least than that of the pure Mo sheet. Lastly, the strengthening mechanism was discussed.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51272207, 51471181 and 51575505)
文摘The NiCrAlY-Mo-Ag composite coatings were prepared by atmospheric plasma spraying. The tribological properties of the composite coatings were investigated from 25 to 900 ℃ in details. The tribo-layer formed on the worn surface of the composite coatings and influenced the tribological properties at different temperatures. The addition of silver could effectively decrease the friction coefficient and wear rate of the coatings at the wide range of temperature. The rubbing process could form the nickel molybdate and promote the formation of silver molybdate within the worn surfaces at high temperature. The synergistic lubricating effects of nickel molybdate and silver molybdate are attributed to the improvement of the tribological properties of coatings at high temperature.
