Yttrium aluminum garnet （YAG） ceramic fibers were prepared by sol-gel with aluminum chloride,aluminum powder,yttrium oxide and acetic acid as raw materials. Boric acid was added into YAG precursor sol to study the effects of boric acid on the spinnability of sol,and crystallization temperature and microstructure of YAG fibers. The results indicate that addition of boric acid has no effect on the sol spinnability. Upon 2 h calcination at 1 000 ℃ ,YAG gel fibers are fully crystallized into YAG. The addition of boric acid can improve the fiber crystallization and decrease the crystallization temperature. Larger grains and intergranular voids can be observed on the surface of the fibers with boric acid.

The thicker 93W-4.9Ni-2.1Fe tungsten heavy alloy sheets were prepared by powder rolling-stacking sintering. The comparison of microstructure and properties was conducted between single sintered tungsten alloy sheets and stacking sintered ones （i. e. thicker tungsten alloy sheets）,and the influences of cold-rolling on microstructure and properties of stacking sintered alloy sheets were studied. The results show that the thicker tungsten heavy alloy sheets can be prepared with homogeneous microstructure and well combined layers by powder rolling-stacking sintering, and their relative density, hardness and tensile strength are comparable with those of single sintered alloy sheets. Moreover,the mechanical properties of stacking sintered alloy sheets are improved significantly by cold-rolling. Therefore, powder rolling-stacking sintering is effective for preparation of the thicker tungsten heavy alloy sheets.

Abstraet..W-10Cu composite materials were prepared by high velocity compaction-cold forging-copper infil tration. Meanwhile,investigation was made on the influences of particle size and single sample weight of W powders on the microstructure and properties of the materials. The results show that the relative density of W skeleton decreases with the increase of single sample weight before and after cold forging. Upon compaction of the mixed powders,W skeleton has the greatest relative density,yet it is not satisfactory to W-10Cu composite material,of which the relative density should be no less than 81%. By cold forging,the maximum relative density of all the types o{ W skeletons can reach 81%, and among them W skeleton com- pacted with medium-grained powders has the greatest relative density. The W-10Cu composite materials with dense and uniform microstructure can be prepared by high velocity compaction-cold forging-copper in- filtration with three types of powders and they can also meet the performance requirement for electronic packaging materials. Keywords ： W-10Cu ; W powders ; particle size; single sample weight; W skeleton; electronic packing

Abatract： Characteristics and the architectural performance of titanium and its alloys are introduced, focusing on the examples of their applications in the buildings. Current development and existing problems are also summarized of titanium and its alloys as building materials in China, and the future development is pointed out. Keywords ： titanium and its alloy ; building material ; architectural performance ; current application ; prospect

The energy band structures, density of electronic states and absorption spectra of Al-doped, F-doped and Al-F co-doped anatase TiO2 were calculated using the first-principle plane wave ultra-soft pseudo-potential method based on the density functional theory. The results indicate that the band gaps of all the doped TiO2 decrease to different extent,and that of Al-doped TiO2 decreases most obviously. All the doped anatase TiO2 show blue shift of absorption edge at different level,and among them the blue shift of F-doped TiO2 is the maximum. In visible light region, there is notable increase of absorptivity of F-doped TiO2 and the absorptivity of Al-doped TiO2 is moderately increased, while the absorptivity of A1-F codoped TiO2 is not increased.

The contents of A1, Cu, Fe, Ni and Si in Nd-Mg alloy were determined by inductively coupled plasma-atomic emission spectrometry （ICP-AES）, and the optimal analytical spectral lines and detection limits of the instrument for the elements were chosen. The relative standard deviation is 2%-5% of the measured values with the above method,and the standard addition recovery is 97.5-105.9%.

Ultrafine-grained cemented carbide has good comprehensive physical properties. In this article, corrosion effects and mechanisms of WEDM working liquid on ultrafine-grain cemented carbide were studied by soaking tests of cobalt plate and actual cutting tests of cemented carbide, and SEM and EDX characterization. The results show that both water and triethanolamine in WEDM working liquid can lead to Co accelerated leaching from ultrafine-grained cemented carbide. The stable WC skeleton is destroyed due to the loss of Co binder phase during wire cut electrical discharge machining. At high temperature, W on the surface of ultrafine-grained cemented carbide is oxidized to WO3, and then dissolved into WEDM working fluid in the form of tungstate ion, accelerating the loss of WC in ultrafine-grained cemented carbide.

Micro-modeling machining experiments were carried out for an end spiral groove on YG8 cemen- ted carbide by using a lamp-pumped YAG T50 series laser marking machine. Effects of the machining pa- rameters were studied on the quality of micro-modeling including effective vector step length, effective vector step delay,Q frequency and laser current. The results show that with the increase of effective vector step length, groove depth decreases and its surface roughness increases. With the effective vector step or Q frequency increases, both groove depth and its surface roughness decrease. With laser current increases, both groove depth and its surface roughness increase. The optimal laser machining parameters for micro- modeling on cemented carbide surface are effective vector step length of 0. 001 mm,effective vector step delay of 60μs,Q frequency of 20 kHz and laser current of 16 A.

The comparison of grades and properties is conducted between cemented carbide buttons at home and abroad. Meanwhile, the latest development is summarized in respect of alloy materials, preparation process and button profile of cemented carbide buttons, and the improvement methods of alloy materials are detailed in respect of superfine-crystallization and nano-crystallization, functional gradient optimization and trace element addition. Besides, the suggestions are made to the future development of cemented carbide buttons.

Preliminary data collection, statistical calculation and analysis is conducted on the patent development history, distribution and management in the cemented carbide enterprises. The main problems of patent work in the cemented carbide enterprises are pointed out, and some suggestions and measures are presented.