The surface of Titanium Hydride (TiH 2) is coated by Nano Titanium Dioxide (TiO 2) particles prepared in both of methods of hydrolysis reaction of Ti(OC 4H 9) 4 and base precipitation reaction of Ti(SO 4) 2. ...The surface of Titanium Hydride (TiH 2) is coated by Nano Titanium Dioxide (TiO 2) particles prepared in both of methods of hydrolysis reaction of Ti(OC 4H 9) 4 and base precipitation reaction of Ti(SO 4) 2. TiH 2 coated with nano TiO 2 particles, in which there is an oxidation film on its surface, shown in the experiments, will obviously achieve good effects on releasing hydrogen slowly in high temperature. There are different structures and properties of TiH 2 coated by nano TiO 2 particles prepared in different ways in high temperature, which can influence on releasing hydrogen.展开更多
Nanocrystalline TiO2 was prepared by high frequency plasma chemical vapor deposition (HF-PCVD). The effects of additive AlCl3 on crystal phase, particle size and microstructurai parameters of TiO2 nanocrystallites wer...Nanocrystalline TiO2 was prepared by high frequency plasma chemical vapor deposition (HF-PCVD). The effects of additive AlCl3 on crystal phase, particle size and microstructurai parameters of TiO2 nanocrystallites were investigated by X-ray diffraction(XRD) and transmission electron microscopy (TEM). The nanocrystallites obtained experimentally are mixture of anatase and rutile, the uniform diameters of particles are about 30 nm. The phase transformation from anatase to rutile was accelerated by AlCl3, and rutile content is increased from 26.7 wt pct to 53.6 wt pct with increasing of addition of AlCl3 from 0.0 wt pct to 5.0 wt pct. The particle size is reduced and the size distribution becomes very narrow. The crystal lattice constants have the trend to decrease, and celi volumes appear as shrinkable.展开更多
Al_(0.4)CoCrFe_(2)Ni_(2)high-entropy alloys with different additions of TiO_(2) nanoceramic particles(0,1.25vol.%,2.5vol.%,3.75vol.%and 5vol.%,respectively)were prepared by using the vacuum arc melting method.The effe...Al_(0.4)CoCrFe_(2)Ni_(2)high-entropy alloys with different additions of TiO_(2) nanoceramic particles(0,1.25vol.%,2.5vol.%,3.75vol.%and 5vol.%,respectively)were prepared by using the vacuum arc melting method.The effects of TiO_(2) addition on the crystal structure,microstructures and mechanical properties of the alloy were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and tensile testing.The microstructure analysis shows that the TiO_(2)nano-ceramic particles added in the alloy are decomposed,and a small amount of Al_(2)O_(3)and a great number of intermetallic compounds(γ'phases)with simple cube structure are formed.Theγ'phases are enriched at inter-dendrite,which increases the resistance of dislocation movement during the deformation of the alloy,thus balancing the problem of high plasticity and low strength of the alloy.When the addition of TiO_(2)is 2.5vol.%,the strength of the high-entropy alloy reaches the maximum of 489 MPa,which is 11.1%higher than the matrix alloy composed of single FCC phase.展开更多
文摘The surface of Titanium Hydride (TiH 2) is coated by Nano Titanium Dioxide (TiO 2) particles prepared in both of methods of hydrolysis reaction of Ti(OC 4H 9) 4 and base precipitation reaction of Ti(SO 4) 2. TiH 2 coated with nano TiO 2 particles, in which there is an oxidation film on its surface, shown in the experiments, will obviously achieve good effects on releasing hydrogen slowly in high temperature. There are different structures and properties of TiH 2 coated by nano TiO 2 particles prepared in different ways in high temperature, which can influence on releasing hydrogen.
文摘Nanocrystalline TiO2 was prepared by high frequency plasma chemical vapor deposition (HF-PCVD). The effects of additive AlCl3 on crystal phase, particle size and microstructurai parameters of TiO2 nanocrystallites were investigated by X-ray diffraction(XRD) and transmission electron microscopy (TEM). The nanocrystallites obtained experimentally are mixture of anatase and rutile, the uniform diameters of particles are about 30 nm. The phase transformation from anatase to rutile was accelerated by AlCl3, and rutile content is increased from 26.7 wt pct to 53.6 wt pct with increasing of addition of AlCl3 from 0.0 wt pct to 5.0 wt pct. The particle size is reduced and the size distribution becomes very narrow. The crystal lattice constants have the trend to decrease, and celi volumes appear as shrinkable.
基金supported by the Open Project of State Key Laboratory of Light Alloy Casting Technology for High-end Equipment(LACT-009)the Program for Natural Science Foundation of Liaoning Province(2022-BS-181).
文摘Al_(0.4)CoCrFe_(2)Ni_(2)high-entropy alloys with different additions of TiO_(2) nanoceramic particles(0,1.25vol.%,2.5vol.%,3.75vol.%and 5vol.%,respectively)were prepared by using the vacuum arc melting method.The effects of TiO_(2) addition on the crystal structure,microstructures and mechanical properties of the alloy were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and tensile testing.The microstructure analysis shows that the TiO_(2)nano-ceramic particles added in the alloy are decomposed,and a small amount of Al_(2)O_(3)and a great number of intermetallic compounds(γ'phases)with simple cube structure are formed.Theγ'phases are enriched at inter-dendrite,which increases the resistance of dislocation movement during the deformation of the alloy,thus balancing the problem of high plasticity and low strength of the alloy.When the addition of TiO_(2)is 2.5vol.%,the strength of the high-entropy alloy reaches the maximum of 489 MPa,which is 11.1%higher than the matrix alloy composed of single FCC phase.
