W18Cr4V钢冷镦冲头沉积氮化钛研究

用活化反应离子镀技术在Ｗ１８Ｃｒ４Ｖ钢冷镦冲头上沉积氮化钦，对氮化钛涂层进行了晶体结构和组织形貌分析，测试了涂层深度及硬度，涂层冷镦冲头经生产应用考核，使用寿命提高２～３倍．     

Low pressure synthesis of boron nitride with(C2H5)2O·BF3 and Li3N precursor

Cubic boron nitride(c-BN) was synthesized through benzene thermal method at a lower temperature of 300 ℃ by selecting liquid(C2H5)2O·BF3 and Li3N as reactants. Hexagonal boron nitride(h-BN) and orthorhombic boron nitride(o-BN) were also obtained. The samples were characterized by X-ray powder diffractometry and Fourier transformation infrared spectroscopy. The results show that all the BF3, BCl3 and BBr3 in the same family compounds can react with Li3N to synthesize BN since the strongest bond of B-F can be broken. Compared with BBr3, liquid (C2H5)2O·BF3 is cheaper, less toxic and more convenient to operate. Li3N not only provides nitrogen source but also has catalytic effect on accelerating the formation of c-BN at low temperature and pressure.     

Preparation of titanium dioxide from titania-rich slag by molten NaOH method

Preparing titanium dioxide from titania-rich slag(TiO2 73wt%) by molten NaOH method has been developed.The effects of tem-perature and reaction time on the titanium conversion were investigated.The results showed that temperature had significant influence on the titanium conversion as well as the structure of the product.About 92% of titanium in the titania-rich slag could be converted after reacting with NaOH at 500℃ for 1 h.Metatitanic acid was formed through the steps of washing treatment,acid dissolution,and hydrolysis.Well-dispersed spherical titanium dioxide particles with an average size of 0.1-0.4 μm can be obtained by calcination of metatitanic acid.In addition,the content of titanium dioxide in the product is up to 98.6wt%,which can be used as pigments after further treatment of coating and crushing.     

脉冲激光沉积CN_x薄膜的微观组织结构表征

利用脉冲激光烧蚀CNx靶,在室温至450℃基片温度时沉积CNx薄膜.利用扫描电镜(SEM)、X射线衍射(XRD)、X射线光电子谱(XPS)和拉曼光谱(Raman)等对CNx薄膜的表面形貌、化学成分、结晶性以及价键状态进行了分析.结果表明:所得CNx薄膜呈非晶状态,表面形貌与沉积温度密切相关,基片温度高于150℃时薄膜表面较为光滑.随着基片温度的增加,薄膜中C—N键的面积分数从31.2%逐渐减少至14.1%,N—sp3C和N—sp2C键的面积分数随之减少,300℃时最利于形成sp3键.Raman光谱中比值ID/IG总体呈上升趋势,G峰的位置向高波数(高频)方向移动且半高宽(FWHM)下降,薄膜由CNx薄膜的无序结构逐渐向高有序化程度类石墨结构转变,石墨化程度增加.     

Preparation of calcium carbonate particles coated with titanium dioxide

The preparation of a new mineral composite material,calcium carbonate particles coated with titanium dioxide,was studied.The mechanism of the preparation process was proposed.The new mineral composite material was made by the mechanochemical method under the optimum condition that the mass ratio of calcium carbonate particles to titanium dioxide was 6.5:3.5.The mass ratios of two different types of titanium dioxide(anatase to rutile) and grinding media to grinded materials were 8:2 and 4:1 respectively,and ...     

一种改性钛渣钛组分的分离方法

研究了碱浸出过程中的影响因素,考察了浸出温度,NaOH溶液的浓度,以及物料粒度和液固比等因素对于浸出效果和回收率的影响.得到了碱浸阶段适宜的工艺条件为：溶液中NaOH的质量分数为15%、浸出温度100℃、浸出时间6 h、液固比20 mL/g、钛渣粒度小于38μm,搅拌速度500 r/min.采用三段浸出的方法获得了品位为91.42%,回收率为78.47%的人造金红石产品.     

Preparation of silicon carbide nitride films on Si substrate by pulsed high-energy density plasma

Thin films of silicon carbide nitride （SiCN） were prepared on （111） oriented silicon substrates by pulsed high-energy density plasma （PHEDP）. The evolution of the chemical bonding states between silicon, nitrogen and carbon was investigated as a function of discharge voltage using X-ray photoelectron spectroscopy. With an increase in discharge voltage both the C 1s and N 1s spectra shift to lower binding energy due to the formation of C--Si and N--Si bonds. The Si--C--N bonds were observed in the deconvolved C ls and N ls spectra. The X-ray diffractometer （XRD） results show that there were no crystals in the films. The thickness of the films was approximately 1-2 μm with scanning electron microscopy （SEM）.     

Low pressure synthesis of boron nitride with (C2H5)2O · BF3 and Li3N precursor

Cubic boron nitride(c-BN) was synthesized through benzene thermal method at a lower temperature of 300 °C by selecting liquid (C₂H₅)₂O · BF₃ and Li₃N as reactants. Hexagonal boron nitride(h-BN) and orthorhombic boron nitride(o-BN) were also obtained. The samples were characterized by X-ray powder diffractometry and Fourier transformation infrared spectroscopy. The results show that all the BF₃, BCl₃ and BBr₃ in the same family compounds can react with Li₃N to synthesize BN since the strongest bond of B-F can be broken. Compared with BBr₃, liquid (C₂H₅)₂O · BF₃ is cheaper, less toxic and more convenient to operate. Li₃N not only provides nitrogen source but also has catalytic effect on accelerating the formation of c-BN at low temperature and pressure. Foundation item: Projects(20273007,50372006) supported by the National Natural Science Foundation of China     

Preparation of bentonite supported nano titanium dioxide photocatalysts by electrostatic self-assembly method

Electrostatic self-assembly method (ESAM) was used to prepare bentonite supported-nano titanium dioxide photocatalysts. The materials were characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Methyl orange was used to estimate the photocatalytic activity of the materials. The effects of the calcination temperature and silane dosage on the photocatalytic activity of the samples were investigated. The experimental results show that the bentonite facilitates the formation of anatase and restrains the transformation of anatase to rutile. Part of nano-size TiO2 particles insert into the galleries of bentonite. The photocatalysts exhibit a synergistic effect of adsorption and photocatalysis on methyl orange. Photocatalysts prepared by ESAM method exhibit higher photocatalytic activity and better recycle ability than those of the traditional method.     

Preparation and photocatalytic properties of Fe-doped TiO_2 nanoparticles

1　INTRODUCTIONAsagoodphotocatalyst ,TiO2 hasattractedex tensiveinterestduetoitsvariousexceedingpropertieswithalargesurfacearea ,nontoxicity ,highstability ,lowcost ,andhighcatalysisforchemicalwastetreat ment[1] .PhotocatalyticreactionsoccuronthesurfaceofTiO2 particles .Whenaphotonwithenergyhve qualtoorexceedingtheTiO2 energygap(Eg =3.2eV ,λ=387nm)isabsorbedbyaTiO2 particle ,electron holepairswillbegenerated ,whichcanre duceandoxidatethepollutantsinbothwaterandair .Itisgenerallybelie…     

Synthesis of brookite-typed titania from titanium chloride solution

The brookite-phase TiO_2 was prepared by a hydrothermal synthesis of titanium chloride solution. The thermolysis time and the pH value of the solution were controlled during the synthesis. X-ray diffraction experiments showed that TiO_2 powders partially containing the brookite-phase were successfully obtained. A great amount of OH-in the reaction solution was found to be important to obtain the brookite phase because the intermediate complex leading to the brookite phase consumes more OH- than other phases like the rutile.     

Effect of electropolishing on electrochemical behaviours of titanium alloy Ti-10V-2Fe-3Al

The electrochemical behaviours of titanium alloy Ti-10V-2Fe-3Al after electropolishing in a self-developed electrolyte in comparison with conventional grinding were studied by electrochemical impedance spectroscopy (EIS).Optical microscopy (OM),scanning electron microscopy (SEM),atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) were used to evaluate the surface characteristics of the alloy.It was found from the EIS experiments that the polarization resistance (Rp) was increased,the double layer capacitance (Qc) was decreased and the electrochemical impedance of the alloy was enhanced by electropolishing.The electropolished surface was flat,smooth and bright and its roughness was 3.310 nm.To underline the advantage of electropolishing process against grinding to provide the anodic oxidation process with a higher quality substrate,the ground and electropolished titanium alloys were anodized in parallel under the same conditions.The corrosion behaviours of the two kinds of anodized titanium alloys were compared.It was revealed that electropolishing generated a high quality substrate and improved the corrosion resistance of anodic oxide film formed on titanium alloy Ti-10V-2Fe-3Al.Furthermore,the mechanism of electropolishing improving the corrosion resistance of the anodic oxide film was proposed.     

Preparation and visible-light photocatalytic property of nanostructu- red Fe-doped TiO2 from titanium containing electric furnace molten slag

Nanostructured Fe-doped titanium dioxide was synthesized from titanium containing electric furnace molten slag （TCEFMS） by using an alkali fusion, followed by a hydrolyzation-acidolysis-cMcination route. The effects of Mkali/slag mass ratio, calcinating temperature, calcinating time, and water/slag mass ratio on the extraction efficiency and purity of products were systematically studied in this paper. It is indicated that the best extraction efficiency of nanostructured Fe- doped titanium dioxide is 99.35%, when the molten slag is calcinated at 700℃ for 1 h with the mass ratio of alkali/molten slag of 1.5：1. The influence of alkali/slag mass ratio on the photocatalytic activity of final products was evaluated by the photodegradation of methyl blue under visible light irradiation. A maximum photodegradation efficiency of 88.12% over 30 min was achieved under the optimum conditions.     

利用煤矸石制取高纯度超微细钛白粉的试验研究

本文对利用煤矸石制取高纯度超微细钛白粉的可行性进行了研究,对焙烧温度、反应温度、pH值、水解、水洗操作、盐处理及煅烧等影响因素进行了分析,通过对所制钛白粉产品质量检验得出:利用煤矸石制取钛白粉是一种切实可行的方法。     

丙三醇钛直接热分解制备纳米二氧化钛

针对以易水解的一元醇钛盐为前驱物,采用溶胶-凝胶水解法制备纳米二氧化钛时浪费大量溶剂、抑制剂和造成环境污染的问题,制备出一种新型的丙三醇钛盐,并通过直接焙烧丙三醇钛的方法制备了纳米级二氧化钛粉体.运用IR、XRD、DSC、SEM和TEM等手段对制得的丙三醇钛和纳米二氧化钛粉体进行了表征.结果表明,由丙三醇钛直接热分解可制备出具有完整、呈片状结构晶形的纳米二氧化钛,该方法简单可行,污染小、成本低,制得的粉体粒径主要分布在15~50nm范围内.     

Preparation and photocatalytic properties of Fe-doped TiO2 nanoparticles

Nanocrystalline Fe-doped TiO2 with size of 60-70 nm was prepared by a sol-gel technique, followed by freeze-drying treatment for 2 h. Thermogravimetric and differential thermal analyses, X-ray diffraction, scanning electron microscope, laser diffraction particle size analyzer and OV-Vis spectrophotometer technologies were used to characterize the product. The photocatalytic activities of the samples were evaluated by the degradation of wastewater of paper-making. The effects of Fe ion implantation on the photocatalytic activity of TiO2 were also dis-cussed. The results show that the iron content plays an essential role in affecting the photocatalytic activity of the Fe-doped TiO2 and the optimum content of Fe-doped is 0.05% (mass fraction). The photocatalytic activity of sam-ples with lower content of Fe-doped is higher than that of pure TiO2 in the treatment of paper-making wastewater.The photo-degradation effect of paper-making effluent is the best by means of Fe-doped TiO2 with 0.05 % Fe.     

近α钛合金砂带磨削的磨粒磨损研究

针对锆刚玉磨料砂带和近α钛合金工件材料的特点,通过三维体式显微镜对锆刚玉磨料砂带干式磨削近α钛合金时的磨粒磨损面积、磨粒高度、磨损量和金属去除量进行了研究;同时采用扫描电子显微镜和能量分散光谱扫描对磨粒磨损形态进行研究;并分析不同磨粒磨损阶段对磨削工件表面的影响。研究表明:磨粒磨损形态有脱落,磨耗和破碎,主要以磨耗磨损为主;砂带线速度vs、进给速度vw和磨削深度ap增大均使砂带磨粒磨损加剧。在低切削速度、低进给量、低切削深度下锆刚玉磨料砂带加工钛合金时的切削加工性最好,因此锆刚玉磨料砂带适用于钛合金的干式磨削加工。