Take advantage of the characteristics of tungsten powder, we often get it coated by metals for the new characteristics we want.

The tungsten powder coated by copper could be prepared by chemical plating with selfmade equipments. The microstructure and component of coating powder was recorded by the scanning electronic microscopy and x-ray diffraction instrument. It is shown that chemical plating method can be used to prepare the copper coated tungsten powder, and the coating is uniform as well as the thickness achieves 0.45 μm. The optimum technological parameters of chemical plating on the tungsten powder surface are that copper sulfate is 20 g/L, sodium potassium tart rate is 13.6 g/L, dis-odium ethylene diamine tetra acetate is 27.3 g/L, formaldehyde is 15 ml/L, pH value equals 12,temperature is 60 ℃,and the grain size of tungsten powder is 10 μm.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com

Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

In addition the blue tungsten oxide form affects tungsten powder particle size the process parameters also affect the size of tungsten powder. Influence of Process Parameters on the tungsten powder particle size is mainly hydrogen mode, heating systems and hydrogen influence humidity. There has two kinds of hydrogen mode one is cis hydrogen mode and the other is inverse hydrogen, the study found that cis hydrogen mode reduction of tungsten powder particle size is significantly thinner than the inverse hydrogen mode. ATB phase blue tungsten powder at low temperature with cis hydrogen mode can producing tungsten powder particle size thinner, narrow distribution, and the nature the better. In heating system, the researchers found that heating from a low temperature and the heating process more gentle process are good for the producing fine tungsten powder. At the same time hydrogen humidity also impact on the tungsten powder particle size, at the same other process parameters, continuously push the boat and single boat reduction effect is not the same, which is mainly due to different hydrogen humidity. Cis hydrogen mode is good for retrain tungsten powder grow up so producing of fine particles tungsten powder should be used cis hydrogen mode.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

 

Nanosized tungsten powder with a particle size of 60 nm was used as raw material, which was prepared by catalysis-gel process. By means of compacting with a steel die, the green compact was sintered in hydrogen so as to look into its shrinkage kinetic curve. By these methods the changes of grain size and relative density during sintering at different temperatures and different sintering time were tested. Now we could clearly see that the compact of nanosized tungsten powder begins to shrink at the temperature of 200 ℃ and stops shrinking at 1 300 ℃.And we can also se that  the highest shrinkage rate comes out  at 1 225 ℃. From 1 000 ℃ to 1 200 ℃, the relative density increases by 24%. After sintered at 1 200 ℃ for 120 min, the average grain size is 5 μm, and the relative density is 95% at the same time.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com

Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

Blue tungsten oxide forms including composition, phase composition, surface area, particle size and oxygen index and so on. Blue tungsten oxide particle size has a significant impact at the tungsten powder reduction on tungsten powder particle size, which the coarse blue tungsten is good for producing fine tungsten powder, because coarse blue tungsten oxide particles in the process of reduction has good permeability can exclusion vapor water which have a greater advantage. To a certain extent, blue tungsten oxide specific surface area also affect tungsten powder particle size having a large specific surface area of ​​blue tungsten oxide in favor of   producing fine tungsten powder. Because the more advanced blue tungsten oxide surface area, the greater its reaction interface, reducing activity, the better. In the study also found the relative composition of blue tungsten oxide will effect tungsten powder particle size this is also can not be ignored. After comparing the different components of blue tungsten oxide along with the effect of hydrogen reduction found that phase component ATB and W20O58 blue tungsten oxide reduction fine tungsten powder better than other blue tungsten oxide which containing more tungsten trioxide. And with ATB basic phase of blue tungsten, reducing effect at low temperatures is good than other blue-phase component of tungsten. ATB Blue Tungsten is hexagonal structure, because this structure is unstable, having a large number of lattice defects, developed specific surface area, with a high reduction activity.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn