Tungsten copper composite sintered body directly affects the comprehensive performance of final product so that the determination of the relative aspects of density, hardness, conductivity, shrinkage, scanning electron microscopy and crushing strength becomes essential. Next, we will combine the experience of some relevant theoretical principles and production practices as summarized in one by one analysis of the test method.

Relative Density Test: It usually uses Archimedes drainage method, which weighs tungsten copper sintered in the air and in distilled water separately by electronic balance. Subsequently removed with a filter paper and then sintered body dry surface of the water and drying weighed. The conclusion that the actual density tungsten-copper sintered body, the relative density and opening rate formulas based on Archimedes' principle.

Hardness Test: Different from Rockwell hardness of tungsten carbide, tungsten copper products commonly tested by Vickers hardness. The basic process is to measure metallographic sandpaper good surface finish to standard mirror wafer sample was placed on a micro hardness tester, then a relative angle between the plane of a rectangular pyramidal diamond indenter of 136 °, using 0.1kgf (0.98N) pressure pressed into the sample surface. After a period of time (usually set 10S), remove the pressure with a magnification of 40 times optical microscope to accurately measure the length of indentation diagonal by formula Vickers hardness (HV = 0.1891 × F / d², HV Vickers hardness, F is the applied pressure, d is the amount of indentation diagonal arithmetic mean) obtained the hardness.

TIG welding is also known as inert gas shielded arc welding. It usually uses high melting point metal such as thorium tungsten, cerium tungsten, tungsten and other refractory metal as non-consumable electrode of electric arc, using inert gas as the medium of electric arc and protective atmosphere, so that weld pool and electric arc will not affected by air during welding. It was proposed in 1930 when aviation industry has strived to develop at that time. On the other hand, SMAW and SAW welding can not meet airline industry non-ferrous metal welding. Besides, atomic hydrogen welding is more dangerous, and there will be welding line problems. Therefore, in order to meet the aviation industry non-ferrous metal welding requirements, TIG emerged.

Using TIG welding for metal welding not only has stable arc length and tungsten electrode difficult to melt, but also it has good protect effect and reliable crafts. It is suitable for welding non-ferrous metals and their alloys and welding material thickness is generally less than 3mm. TIG welding equipment including: welding power supply, ignition unit and control system; protection gas supply device; cooling water; welding gun and so on.

Tungsten electrode is an important part of TIG welding. Tungsten electrodes, thorium tungsten electrodes, cerium tungsten electrodes, zirconium tungsten electrode, yttrium tungsten electrode, lanthanum tungsten electrode and other composite tungsten electrodes are usually used in TIG welding. Each tungsten electrodes species has its own characteristics. Depending on different welding application can take different tungsten electrodes type. Tungsten electrodes are used in TIG welding having some property requirements:
1. Arc is easy ignition and stable;
2. The arc happens at the electrode front-end, without cathode spots climbing;
3. During welding, electrode consumption and deformation will not affect the property of the arc.

The problem of thermal expansion is an unfavorable factor in many areas, which is widely existing in function and structure materials such as precision components, optical fiber, circuit boards, sensors and fuel cells. ZrWMoO₈ composite ceramic material is an ideal expand controllable material.



Studies have pointed out a method that ammonium paratungstate preparing ZrWMoO₈ composite ceramic material, the steps are as follows:
1. Weighing zirconium oxychloride, aluminum nitrate and dissolving them into 100~150mL of distilled water to prepare a solution A;
2. Dissolving ammonium paratungstate, tetra-hydrate ammonium molybdate, ammonium metavanadate into 100~150mL of distilled water, and heated with stirring to completely dissolve, then to obtain solution B;
3. Both solution A and B are slowly dropped with the same speed  into a round-bottomed flask which is containing 50mL of ethanol, then white precipitate comes into being, stirring is supposed to be continually during the addition for ensuring mixing homogenous;
4. Transferring the solution to an evaporator for evaporation after the addition was completed, and then drying, milling to get a mixed powder;
5. Placing the powder in a muffle furnace at 550~650°C calcined for 2~3 hours, and then taking out to cool down to obtain a precursor;
6. The precursor powder is placed in a mold to form cylindrical specimens;
7. The precursor sample was placed in a molybdenum crucible with stamped, and placed into another ceramic crucible with a lid, the ceramic crucible is place into the resistance furnace when its temperature heated to 940~970°C. The ceramic crucible is calcined for 2 hours, and transferred into a dryer to cool down to room temperature after taken out and cooled down for 2 minutes, then we obtain the ZrWMoO₈  composite ceramic material.

Handling the environmental pollution is the focus and urgent problems for human today, especially governance of organic pollutants. Photocatalytic technology has the advantages that low energy consumption, clean mild conditions, no secondary pollution, etc. in purify organic pollutants, being a green environmental control technology which has a broad application prospect. Tungsten bismuth (Bi₂WO₆), as a new type of bismuth series light catalyst, is a multi-compound with layered structure. And because of its high catalytic activity under visible light irradiation, it can decompose water to produce oxygen and degradation of organic matter, making it particularly suitable for environmental pollution control and solar energy conversion.

Studies have pointed out a method that uses ammonium paratungstate as a raw material for preparing bismuth tungstate with three-dimensional wheel-like hierarchical structure. The steps are as follows:

1. Dissolving the bismuth salt in dilute aqueous acid to form a clear solution;
2. Dissolving ammonium paratungstate by a certain percentage in deionized water to obtain APT aqueous solution;
3. Add APT solution slowly into the clear solution obtained in Step 1, and continue stirring for 0.5~l hour to obtain solution named A;
4. Dissolving an amount of sulfate in deionized water, and slowly adding it into solution A, and continue stirring for 0.5~l hour, to obtain solution named B;
5. Transferring B solution into a stainless steel autoclave containing Teflon-lined, and heated to 150~200°C for 10~30h, to generate products;
6. The products is washed and carried out centrifugation, and dried under vacuum at 50~100°C, to obtain the bismuth tungstate with three-dimensional wheel-like hierarchical structure.