The process conditions were investigated of silicon extraction and calcium silicate preparation from the filter residue in the process of titanium extraction of roasted titanium slag with concentrated sulfuric acid. The main process steps include alkali-solution and calcification. The effects were investigated of NaOH-residue mass ratio, reaction temperature, reaction time and liquid-solid mass ratio on SiO2 extraction rate from the filter residue during alkali-solution. The optimum operating conditions of alkali-solution are obtained as follows： reaction temperature of 190 ℃ ,NaOH-residue mass ratio of 3 ： 1 ,liquid-solid mass ratio of 4.5 ： 1 and reaction time of 60 min. And SiO2 extraction rate is 74.09 % under the above conditions. The effects were investigated of reaction temperature and reaction time on calcification rate of sodium silicate solution during calcification. The optimum operating conditions of calcification are obtained as follows： reaction temperature of 100 ℃ and reaction time of 45 min. And the calcification rate of sodium silicate solution is 94% under the above conditions. Calcium silicate powder product contains 44.36% CaO and its main phase is CaSiO3 ,having loose and porous morphology and micron-level particle size.

WO3 and W powders were prepared with Cr-doped APT as raw material,and their physicochemical properties were studied. The results show that Cr-doped WO3 and W powders have consistent crystal structure with ordinary WO3 and W powders,and Cr exists in the form of Cr2O3 in the two powders. Compared with ordinary W powder,Cr-doped W powder has smaller particle size, good uniformity and complete crystal structure. Cr can effectively inhibit vapor deposition and growth of W power during reduction, but the oxygen index is slightly higher. Cr distribution in both WO3 and W powders is of good macroscopic and microscopic uniformity.

Using the refractory powders of pure molybdenum as raw material, the molybdenum billet with relative density of 96.45% was prepared by high-pressure torsion at 350 ℃ temperature and 1.5 GPa pressure. The rules of pore evolution and densification strengthening were analyzed with various detection methods in the process of high-pressure torsion. The effect was studied of height to diameter ratio of prepressed molybdenum billets on the microstructure and properties of high-pressure torsion molybdenum billets. The results show that the smaller the height to diameter ratio, the greater the material equivalent shear strain,and the higher the relative density and hardness value of high-pressure torsion molybdenum billets. Furthermore,its internal sub-grain size refinement and microscopic strain accumulation are more obvious. When the height to diameter ratio is reduced from 0.5 to 0.3, the dislocation density caused by grain refinement and strain accumulation increases from 1.67 ×10^14 m 2 to 3.03×10^14 m-2.

TiN coatings were deposited on the surface of cemented carbide substrate by multi-arc ion plating. The effect was studied of total gas flow on the surface morphology and mechanical properties of TiN coatings. The surface morphology of the coatings was observed by SEM. The pixel distribution of the coat- ings was analyzed by ImageJ software. And the mechanical properties of TiN coatings were evaluated by automatic scratch spectrometer and nanoindenter. The results show that with total gas flow increasing, both the amount and size of microparticles on coating surface increase, the adhesion force of the coatings in- creases firstly and then decreases, but its micro-hardness decreases firstly and then increases. When the total gas flow is 300 mL/min,the coatings have the most gas pits and the highest adhesion force of 106.4 N. When the total gas flow is 100 mL/min,the coatings have the highest micro-hardness of HV3 021.

In/Al2O3 catalyst was prepared with impregnation method and coprecipitation method, respectively,and research on selective reduction of NOx with the catalyst was carried out. The results show that the catalyst prepared by coprecipitation has higher low-temperature activity and NO selectivity. The bimetal component catalyst of In-Ti/Al2O3 was obtained by the carrier modification with transition metal Ti. And In-Ti/Al2O3 has high activity due to amorphous In oxides and high specific surface area. The added TiO2 can weaken the interaction between In and Al2O3 to form amorphous InTiO2 crystal, resulting in low- er reduction temperature of In.

The effects were studied of brazing parameters on interfacial microstructure, intermetallic com- pound layer thickness and mechanical properties of SnAg0.5CuZn0.1Ni/Cu lead-free brazed joints by OM, XRD, TEM,SEM and tensile testing. The results show that 0.1% Ni addition can obviously refine the pri- mary/9-Sn phase and eutectic microstructure of SnAg0.5CuZn solder alloy. The brazed joint has the maxi- mum shear strength of 45.6 MPa when brazing temperature is 270 ℃ and brazing time is 240 s. All the interfacial roughness,intermetallic compound layer thickness and the shear strength of the brazed joints vary with the change of brazing parameters.

The effects of current density, bath temperature and pH value on hardness of Ni-Co alloy coatings were investigated with single variable method in sulfate system. The optimal technological conditions were determined as follows： the bath temperature is 45 ℃ ,pH value is 3, and the current density is 6 A/dm2. Under these conditions, the Ni-Co alloy coatings with high hardness and good bonding properties on the CuCrZr matrix were prepared. The influences of annealing temperature on hardness and texture of Ni-Co alloy coatings were analyzed. The results show that with the increase of the annealing temperature, the hardness of the coatings increases firstly and then decreases,and the highest HV0.05value reached 506.2 at 300 ℃. After annealing,the coatings exhibits a strong （111） texture.

The orthogonal experiment was carried out of high speed milling of superalloy GH4169 with KYHS10 ceramic tool. The effects were studied by range analysis of milling speed,milling depth,and feed per tooth on the surface roughness of the machined materials. The influencing law was analyzed of each machining parameter on surface roughness. Aprediction model of surface roughness was established,and its reliability was verified. The results show that the primary and secondary influence factors on the surface roughness are milling depth, feed per tooth and milling speed. The surface roughness gradually decreases with the increase of the milling speed, but increases with the increase of the milling depth and feed per tooth.

Basic properties of several common molten salts are introduced as well as the advantages and disadvantages of molten salt synthesis method. The action mechanisms of molten salts for preparing inorganic powder materials and their selection principles are summarized. The latest development is reviewed on preparing inorganic powder materials such as oxides and their composite powders, nitrides and carbides by molten salt synthesis. And the future application of molten salt synthesis method for preparing inorganic powder materials is also pointed out.

Ti content in Sc2 O3 was determined by spectrophotometry. Sc·O3 is decomposed by hydrochloric acid,Cu,Co and Ni are separated by NH3 · H2O precipitation,Ti is separated from Sc with H2C2O4 saturated solution,and then Ti content can be determined with the colorimetric method based on the yellow complex generated between Ti4＋ and H2O2 in 0.9-1.8 mol/L H2SO4 medium. The dosage of H2C2O4 and H3PO4 was investigated. This method is suitable for the determination of 0.01%-0. 50% TiO2 content in Sc2O3, and both its standard addition recovery and precision are in line with experimental requirements.