baoyu135国产精品免费_成人精品视频一级毛片_亚洲中字无码A∨电影在线观看_国产免费高潮白浆二区三区_免费视频在线观看高清无码_精品无码久久国产2024_亚洲AV无码专区牛牛影院_精品第一国产综合精品aⅴ_午夜大片爽爽爽免费影院_日本在线高清视频

Violet tungsten oxide structure:

Violet tungsten oxide which is abbreviated as VTO, is a kind of tungsten oxide. Violet tungsten oxide is finely crystalline powder having unique structure. The appearance of violet tungsten looks like needle and rod. The surface area, grain size and apparent density of violet tungsten oxide are smaller when compared to blue tungsten oxide and yellow tungsten oxide. So its property is also quite different from other tungsten oxides.

Blue tungsten oxide has distinctive edge with specific crystal structure and big surface area. Its surface has different degrees of fragments and full of cracks which is usually used in production of tungsten wire and tungsten carbide. Violet tungsten oxide is very suitable for the production of tungsten metal powder and tungsten carbide.

The structure of violet tungsten oxide is fully distinguished from other tungsten oxides. Every big particle is made from rod like or needle like particles and the inner side of every particle has plentiful cracks. In addition, the structure of violet tungsten has a large gap with low density, which is beneficial to infiltration of hydrogen and water vapor in the process of reduction leading to the reduction can not only start from the surface but also can be carried out simultaneously. The size of violet tungsten oxide is the biggest among other three tungsten oxides because the violet tungsten oxide shows the appearance of rod instead of globular structure like other three tungsten oxides.

In the temperature between 250℃ and 300℃, firstly use the hydrogen or carbon monoxide to reduce tungsten trioxide, then heat the tungsten trioxide in the temperature from 200℃ to 250 ℃, finally get the violet tungsten oxide powder.

Violet tungsten oxide powder has the biggest medium pore volume, the smallest micro-pore volume and fractal dimension value, the narrowest pore size distribution, and the biggest average pore size, which are contributed to reduction of ultrafine tungsten powder.

Violet tungsten oxide feature:

In conclusion, the structure of the violet tungsten oxide looks like a rod or needle having rich crack and big gap conduced to the reduction of violet tungsten oxide. Furthermore, based on a number of advantages of violet tungsten oxide for instance, possess the smallest micro-pore volume and fractal dimension value, the narrowest pore size distribution, and the biggest average pore size and medium pore volume. All of these properties definitely impinge great influence on production of ultrafine tungsten powder instead of benefiting doping process.