Highly pure and dense Ti2AlC and Ti2AlSn0.2C bulks were prepared by hot pressing with molar ratios of 1∶1.1∶0.9 and 1∶0.9∶0.2∶0.85,respectively,at 1450 ℃ for 30 min with 28 MPa in Ar atmosphere.The phase composi...Highly pure and dense Ti2AlC and Ti2AlSn0.2C bulks were prepared by hot pressing with molar ratios of 1∶1.1∶0.9 and 1∶0.9∶0.2∶0.85,respectively,at 1450 ℃ for 30 min with 28 MPa in Ar atmosphere.The phase compositions were investigated by X-ray diffraction (XRD);the surface morphology and topography of the crystal grains were also analyzed by scanning electron microscopy (SEM).The flexural strengths of Ti2AlC and Ti2AlSn0.2C have been measured as 430 and 410 MPa,respectively.Both Vickers hardness decreased slowly as the load increased.The tribological behavior was investigated by dry sliding a low-carbon steel under normal load of 20-80 N and sliding speed of 10-30 m/s.Ti2AlC bulk has a friction coefficient of 0.3-0.45 and a wear rate of (1.64-2.97)×10-6 mm3/(N·m),while Ti2AlSn0.2C bulk has a friction coefficient of 0.25-0.35 and a wear rate of (2.5-4.31)× 10-6 mm3/(N·m).The influences of Sn incorporation on the microstructure and properties of Ti2AlC have also been discussed.展开更多
Compound Zn2Sn0.8Ti0.2O4 was synthesized by a hydrothermal method in which SnCl4-5H2O,TiCl4,ZnCl2 and N2H4-H2O were used as reactants.The composite Zn2Sn0.8Ti0.2O4/C was then prepared through a carbothermic reduction ...Compound Zn2Sn0.8Ti0.2O4 was synthesized by a hydrothermal method in which SnCl4-5H2O,TiCl4,ZnCl2 and N2H4-H2O were used as reactants.The composite Zn2Sn0.8Ti0.2O4/C was then prepared through a carbothermic reduction process using the as-prepared Zn2Sn0.8Ti0.2O4 and glucose as reactants.The structure,morphology and electrochemical properties of the as-prepared products were investigated by XRD,XPS,TEM and electrochemical measurements.In addition,electrochemical Li insertion/extraction in composite Zn2Sn0.8Ti0.2O4/C were examined by ex situ XRD and SEM.The first discharge capacity of Zn2SnO4 is about 1670.8 mA-h/g,with a capacity retain of 342.7 mA-h/g in the 40th cycle at a constant current density of 100 mA/g in the voltage range of 0.05-3.0 V.Comparing with the Zn2SnO4,some improved electrochemical properties are obtained for Zn2Sn0.8Ti0.2O4,Zn2SnO4/C and Zn2Sn0.8Ti0.2O4/C.The composite Zn2Sn0.8Ti0.2O4/C shows the best electrochemical properties,and its first discharge capacity is about 1530.0 mA-h/g,with a capacity retain of 479.1 mA-h/g the 100th cycle.展开更多
基金the Fundamental Research Funds for the Central Universities，the National Natural Science Foundation of China，the Beijing Government Funds for the Constructive Project of Central Universities
文摘Highly pure and dense Ti2AlC and Ti2AlSn0.2C bulks were prepared by hot pressing with molar ratios of 1∶1.1∶0.9 and 1∶0.9∶0.2∶0.85,respectively,at 1450 ℃ for 30 min with 28 MPa in Ar atmosphere.The phase compositions were investigated by X-ray diffraction (XRD);the surface morphology and topography of the crystal grains were also analyzed by scanning electron microscopy (SEM).The flexural strengths of Ti2AlC and Ti2AlSn0.2C have been measured as 430 and 410 MPa,respectively.Both Vickers hardness decreased slowly as the load increased.The tribological behavior was investigated by dry sliding a low-carbon steel under normal load of 20-80 N and sliding speed of 10-30 m/s.Ti2AlC bulk has a friction coefficient of 0.3-0.45 and a wear rate of (1.64-2.97)×10-6 mm3/(N·m),while Ti2AlSn0.2C bulk has a friction coefficient of 0.25-0.35 and a wear rate of (2.5-4.31)× 10-6 mm3/(N·m).The influences of Sn incorporation on the microstructure and properties of Ti2AlC have also been discussed.
基金Project (51004028) supported by the National Natural Science Foundation of China
文摘Compound Zn2Sn0.8Ti0.2O4 was synthesized by a hydrothermal method in which SnCl4-5H2O,TiCl4,ZnCl2 and N2H4-H2O were used as reactants.The composite Zn2Sn0.8Ti0.2O4/C was then prepared through a carbothermic reduction process using the as-prepared Zn2Sn0.8Ti0.2O4 and glucose as reactants.The structure,morphology and electrochemical properties of the as-prepared products were investigated by XRD,XPS,TEM and electrochemical measurements.In addition,electrochemical Li insertion/extraction in composite Zn2Sn0.8Ti0.2O4/C were examined by ex situ XRD and SEM.The first discharge capacity of Zn2SnO4 is about 1670.8 mA-h/g,with a capacity retain of 342.7 mA-h/g in the 40th cycle at a constant current density of 100 mA/g in the voltage range of 0.05-3.0 V.Comparing with the Zn2SnO4,some improved electrochemical properties are obtained for Zn2Sn0.8Ti0.2O4,Zn2SnO4/C and Zn2Sn0.8Ti0.2O4/C.The composite Zn2Sn0.8Ti0.2O4/C shows the best electrochemical properties,and its first discharge capacity is about 1530.0 mA-h/g,with a capacity retain of 479.1 mA-h/g the 100th cycle.
