A series of TaVN-Ag nanocomposite films were deposited using a radio-frequency magnetron sputtering system. The micro- structure, mechanical properties, and tribological performance of the films were investigated. The...A series of TaVN-Ag nanocomposite films were deposited using a radio-frequency magnetron sputtering system. The micro- structure, mechanical properties, and tribological performance of the films were investigated. The results showed that TaVN-Ag films were composed of face-centered cubic （fcc） TaVN and fcc-Ag. With increasing Ag content, the hardness of TaVN-Ag composite films first in- creased and then decreased rapidly. The maximum hardness value was 31.4 GPa. At room temperature, the coefficient of friction （COF） of TaVN-Ag films decreased from 0.76 to 0.60 with increasing Ag content from 0 to 7.93at%. For the TaVN-Ag films with 7.93at% Ag, COF first increased and then decreased rapidly from 0.60 at 25℃ to 0.35 at 600℃, whereas the wear rate of the film increased continuously from 3.91 × 10^-7 to 19.1 × 10^7 mm3/（N·mm）. The COF of the TaVN-Ag film with 7.93at% Ag was lower than that of the TaVN film, and their wear rates showed opposite trends with increasing temperature.展开更多
In order to increase the processability and process window of the selective laser melting(SLM)-fabricated Al−Mn−Mg−Er−Zr alloy,a novel Si-modified Al−Mn−Mg−Er−Zr alloy was designed.The effect of Si alloying on the sur...In order to increase the processability and process window of the selective laser melting(SLM)-fabricated Al−Mn−Mg−Er−Zr alloy,a novel Si-modified Al−Mn−Mg−Er−Zr alloy was designed.The effect of Si alloying on the surface quality,processability,microstructure,and mechanical properties of the SLM-fabricated alloy was studied.The results showed that introducing Si into the Al−Mn−Mg−Er−Zr alloy prevented balling and keyhole formation,refined the grain size,and reduced the solidification temperature,which eliminated cracks and increased the processability and process window of the alloy.The maximum relative density of the SLM-fabricated Si/Al−Mn−Mg−Er−Zr alloy reached 99.6%.The yield strength and ultimate tensile strength of the alloy were(371±7)MPa and(518±6)MPa,respectively.These values were higher than those of the SLM-fabricated Al−Mn−Mg−Er−Zr and other Sc-free Al−Mg-based alloys.展开更多
A 2.5-mm Fe72.5B15.6Si7.8Nb1.7Zr1.7Cu0.7 glassy rod was successfully fabricated using copper mold casting.The introduction of Cu resulted in the formation of large quantities of a-Fe nanoparticles embedded in the glas...A 2.5-mm Fe72.5B15.6Si7.8Nb1.7Zr1.7Cu0.7 glassy rod was successfully fabricated using copper mold casting.The introduction of Cu resulted in the formation of large quantities of a-Fe nanoparticles embedded in the glassy matrix after isothermal annealing.The Fe72.5B15.6Si7.8Nb1.7Zr1.7Cu0.7 nanocrystalline alloy exhibited high saturation magnetization(~1.26 T) and a low coercive force(~0.8 A/m) after annealing at 833 K for 15 min due to the precipitation of ~15-nm-sized a-Fe nanoparticles in the glassy matrix.The structural evolution of the FeBSiNbZrCu amorphous alloy during the annealing process was discussed using a dual-cluster model.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 51374115 and 51574131)Postgraduate Research & Practice Innovation Program of Jiangsu Province (KYCX17-1832)Research Fund of Jiangsu University of Science and Technology (YCX16S-22)
文摘A series of TaVN-Ag nanocomposite films were deposited using a radio-frequency magnetron sputtering system. The micro- structure, mechanical properties, and tribological performance of the films were investigated. The results showed that TaVN-Ag films were composed of face-centered cubic （fcc） TaVN and fcc-Ag. With increasing Ag content, the hardness of TaVN-Ag composite films first in- creased and then decreased rapidly. The maximum hardness value was 31.4 GPa. At room temperature, the coefficient of friction （COF） of TaVN-Ag films decreased from 0.76 to 0.60 with increasing Ag content from 0 to 7.93at%. For the TaVN-Ag films with 7.93at% Ag, COF first increased and then decreased rapidly from 0.60 at 25℃ to 0.35 at 600℃, whereas the wear rate of the film increased continuously from 3.91 × 10^-7 to 19.1 × 10^7 mm3/（N·mm）. The COF of the TaVN-Ag film with 7.93at% Ag was lower than that of the TaVN film, and their wear rates showed opposite trends with increasing temperature.
基金the National Natural Science Foundation of China(Nos.51801079,52001140)the Portugal National Funds through FCT Project(No.2021.04115).
文摘In order to increase the processability and process window of the selective laser melting(SLM)-fabricated Al−Mn−Mg−Er−Zr alloy,a novel Si-modified Al−Mn−Mg−Er−Zr alloy was designed.The effect of Si alloying on the surface quality,processability,microstructure,and mechanical properties of the SLM-fabricated alloy was studied.The results showed that introducing Si into the Al−Mn−Mg−Er−Zr alloy prevented balling and keyhole formation,refined the grain size,and reduced the solidification temperature,which eliminated cracks and increased the processability and process window of the alloy.The maximum relative density of the SLM-fabricated Si/Al−Mn−Mg−Er−Zr alloy reached 99.6%.The yield strength and ultimate tensile strength of the alloy were(371±7)MPa and(518±6)MPa,respectively.These values were higher than those of the SLM-fabricated Al−Mn−Mg−Er−Zr and other Sc-free Al−Mg-based alloys.
基金financially supported by the National Key R&D Program of China(No.2016YFB1100103)the National Natural Science Foundation of China(No.51801079)+1 种基金the Natural Science Foundation for Young Scientists of Jiangsu,China(Nos.BK20180985 and BK20180987)the Natural Science Foundation in Higher Education of Jiangsu,China(No.18KJB430011).
文摘A 2.5-mm Fe72.5B15.6Si7.8Nb1.7Zr1.7Cu0.7 glassy rod was successfully fabricated using copper mold casting.The introduction of Cu resulted in the formation of large quantities of a-Fe nanoparticles embedded in the glassy matrix after isothermal annealing.The Fe72.5B15.6Si7.8Nb1.7Zr1.7Cu0.7 nanocrystalline alloy exhibited high saturation magnetization(~1.26 T) and a low coercive force(~0.8 A/m) after annealing at 833 K for 15 min due to the precipitation of ~15-nm-sized a-Fe nanoparticles in the glassy matrix.The structural evolution of the FeBSiNbZrCu amorphous alloy during the annealing process was discussed using a dual-cluster model.
