Photoelectrocatalytic degradation of rhodamine B using Ti/TiO2 electrode prepared by laser calcination method

The method of Ti/TiO₂ photoelectrode prepared by using laser calcination method instead of oven calcination process was introduced. The prepared TiO₂ film was observed with AFM and XRD. Photoelectrocatalytic degradation of rhodamine B (RB) using this electrode was investigated, and anodic potential and pH were optimized. The laser power applied in this electrode preparation was also discussed, and it indicated that TiO₂ particle prepared with high laser power was crystallized adequately and the photoelectrocatalytic ability was satisfactory. RB degradation was investigated under different conditions, and it showed that photoelectrocatalytic degradation could achieve efficient and complete mineralization of organic pollutant. The photoelectrocatalytic oxidation using the Ti/TiO₂ electrode calcinated by laser was compared with that of the electrode calcinated by furnace, and it showed that the reaction rate of RB degradation using the electrode by laser was faster than that by furnace. Additionally, electrochemical impedance spectroscopy (EIS) was performed at the two different photoelectrodes, which verified the higher photocatalytic activity of the laser-treated electrode further.     

Application of pulse discharge sintering (PDS) technique to rapid synthesis of Ti3SiC2 from Ti/Si/C powders

To synthesize Ti₃SiC₂ samples, pulse discharge sintering (PDS) technique was utilized to sinter elemental powders of Ti/Si/C with stoichiometric and off-stoichiometric ratios in a temperature range of 1200–1500 °C. The results showed that high purity Ti₃SiC₂ could not be obtained from the Ti/Si/C powder with molar ratio of 3:1:2, and Ti₃SiC₂ preferred to form at relatively low sintering temperature for a short time. When 5Ti/2Si/3C and 3Ti/1.5Si/2C powders were sintered for 15 min, the TiC content was respectively decreased to 6.4 and 10 wt.% at 1250–1300 °C. The corresponding relative density of the samples sintered from 5Ti/2Si/3C powder was calculated to be as high as 99% at the temperature above 1300 °C. It is suggested that low-temperature rapid synthesis of Ti₃SiC₂ would be possible through the PDS technique, provided that the composition of the starting powders should be adjusted to be off-stoichiometric ratio from 3:1:2.     

V-5Cr-5Ti合金的动态压缩力学性能及本构关系

利用Hopkinson压杆技术对V-5Cr-5Ti合金动态压缩力学性能进行了实验测试,获得了不同应变率下V-5Cr-5Ti合金的压缩应力—应变曲线,结果显示V-5Cr-5Ti合金具有较强的应变率敏感性。根据实验结果,确定了描述V-5Cr-5Ti合金常温动态性能本构参数,并将实验结果与计算结果进行了比较,两者吻合较好。     

衬底温度对反应溅射TiN_x薄膜结构与电阻率的影响

采用反应磁控溅射方法,在不同Si(100)衬底温度下,制备出了TiNx薄膜。通过X射线衍射(XRD)、扫描电子显微镜(SEM)对TiNx薄膜的物相、微观结构进行了表征,采用电子能谱仪(EDS)测定了TiNx薄膜的成分,运用四探针测试仪测量了TiNx薄膜的电阻率,研究了衬底温度对溅射TiNx薄膜结构与电阻率的影响。研究结果表明:衬底温度从室温升高到600℃时,随着温度升高,TiNx薄膜的(111)晶面衍射峰逐渐增强,500℃后减弱;(200)晶面衍射峰在300℃时最强,之后减弱。随着衬底温度的升高,TiNx薄膜的晶粒逐渐增大,300℃达最大后减小。随着衬底温度升高,TiNx薄膜的N/Ti原子含量比降低,200℃时降到最低为0.99,随后升高,500℃时最高为1.34,随后再次降低。N/Ti原子含量比与薄膜电阻率呈明显反比变化。     

ICP-AES法测定Ti-6Al-4V合金中Al，V的质量分数

用电感耦合等离子体发射光谱（ICP—AEs）法测定了Ti-6Al—4V合金中Al,V的质量分数,研究了元素分析谱线、仪器分析参数、准确度和精密度等,确定了最佳实验条件．结果表明,该方法的加标回收率为101．3％-108．4％,RSD〈2．0％．该方法简便、快速、准确、精密度好,适用于合金中Al,V质量分数的测定．     

反应烧结制备Ti_2AlN-TiN复合材料

采用2Ti/2Al/3TiN粉体为原料,通过反应热压烧结,以制备Ti2AlN-TiN复合材料。采用X射线衍射（XRD）、场发射扫描电镜（FE-SEM）结合能谱仪（EDS）分析试样。研究结果表明,在1350℃保温2h,压力为30MPa,可烧结得到组织细小、致密的Ti2AlN-TiN复合材料。材料中层片状Ti2AlN晶粒长约5m,TiN晶粒大小为1~2m。复合材料具有良好的机械性能,其显微硬度与弯曲强度分别达8.57GPa和450MPa。     

Flux pinning effect of cubic equiaxed morphology and its Ti stabilizing in Nb<Subscript>3</Subscript>Sn superconductors

Two sets of internal-Sn Nb3Sn superconducting strands were fabricated through RRP method, one with 2 wt% of Ti alloyed in Sn core and the other just pure Sn. Four reaction temperatures of 650℃, 675℃, 700℃ and 725℃ and 128 h duration were applied for A15 phase formation heat treatment after Cu-Sn alloying procedure of 210℃/50 h + 340℃/25 h. For the heat-treated coil samples, transport non-Cu JC was examined through standard 4-probe technique and phase microstructure was observed by means of Field Emission Sc...     

Microstructure evolution in Si+ ion irradiated and annealed Ti3SiC2 MAX phase

Ti₃SiC₂ samples were irradiated by a 6-MeV Si⁺ ion to a fluence of 2 $\times$ 10¹⁶ Si⁺ ions/cm² at 300°C followed by annealing at 900°C for 5 h. A transmission electron microscope was used to characterize microstructural evolution. The phase of Ti₃SiC₂ transformed from the hexagonal close-packed (HCP) to a face-centered cubic structure after irradiation. Hexagonal screw dislocation networks were identified at the deepest position of the irradiated area, which are the products of dislocations reactions. After annealing, the irradiated region has reverted to the original HCP structure. High-density cavities and stacking faults were formed along the basal planes. In addition, ripplocations have been observed in the irradiated region in the Ti₃SiC₂ sample after annealing. Our insights into the formation processes and corresponding mechanisms of these defect structures might be helpful in the material design of advanced irradiation tolerance materials.     

Effect of Ti–Si–Fe alloys on microstructure and properties of nitride/oxynitride bonded SiC ceramics sintered under CO/N2 atmosphere

Ti–Si–Fe alloys extracted from high-titanium blast furnace slag were utilized to replace part of the silicon powders, and then nitride/oxynitride bonded SiC ceramics were prepared by reactive sintering in graphite bed. Ti–Si–Fe alloys could react with CO/N₂ at a low temperature (1200 °C), and the addition of Ti–Si–Fe alloys could reduce the nitriding temperature of Si. Density functional theory calculations suggested that Ti–Si–Fe alloys enhanced reaction activity via weakening the strength of CO and NN bonds. The regional equilibrium phase diagrams of Si–C–N–O and Ti–Si–C–N–O under CO/N₂ atmosphere were calculated by thermodynamics. The change of whiskers morphology was observed by scanning electron microscope. Furthermore, the bulk density, the cold modulus of rupture, and the cold compressive strength improved with Ti–Si–Fe alloys content. The results showed that the addition of Ti–Si–Fe alloys not only significantly promoted nitriding of Si and formation of Si₃N₄ whiskers, but also improved the mechanical properties of the samples.     

不同造孔剂对CaCu3Ti4O12多孔陶瓷介电性能的影响

以碳粉和蛋清作为造孔剂,利用固相法制备CaCu3Ti4O12(CCTO)多孔陶瓷.研究了造孔剂含量对CCTO多孔陶瓷体积密度、显微结构和介电性能的影响.结果表明,随着碳粉含量增加,体积密度先增加后减小;而随着蛋清含量增加,体积密度先减小后增加.和碳粉相比,蛋清加入制备的试样具有较小、较均匀的孔隙.当频率大于331.5KHz时,添加碳粉可以降低介电损耗.当频率大于4KHz时,添加碳粉介电常数有所下降.当频率大于2KHz时,添加蛋清可以增大介电损耗,但是增加幅度较小.添加蛋清可以增大介电常数.