Tungsten copper contact has excellent electrical, thermal conductivity and chemical stability, but the problem in densification is always a barrier in its developing way. And this incomplete densification will have an bad influence on the hardness, the strength, wear resistance and arc ablation resistance conversely. So the relevant researchers propose that pressure sintering, a total reduction of chemical and explosive compaction method special process to improve the density of tungsten copper contact material. However, there are some defects in these processes, such as high operation and maintenance costs, be suitable for the parts with small size and so on.

In order to improve the properties of tungsten copper contacts, we combine tungsten copper contact used in high voltage circuit breakers to study HIP process for tungsten copper material impact, and its elimination of the porosity, densification mechanism and related factors. HIP (Hot Isostatic Pressing), it places the product into a closed container, which is applied to each peer pressure while applying heat, under the action of high temperature and pressure, the product can be sintered and densified. HIP has many advantages, such as combines the advantages of hot pressing with isostatic pressing, lower molding temperature, excellent densification and performance, which is essential for high-performance material manufacturing; now, in the United States, Japan and Europe to achieve the industrial, marine, aviation, aerospace, automotive and other fields have been widely used.

Tungsten alloy shielding for digital compound machine is used to shield the radiation released from the digital compound machine. Digital compound machine, also known as copying machine, is the ultimate tool for the modern office. It is a machine that outputs document in the form of laser printing and can edit and operate images and text as required. In addition to the basic function of copying, it also can be used for printing, scanning, fax, etc. Digital compound machine is to translate the optical signals of original manuscript scanned by the optical system into electrical signals by CCD, then process the image signal through digital image processing circuit and input them into the laser modulator. Modulated laser beam will scan photosensitive drum which is charged to produce electrostatic effect, and complete the copying process after developing, transfer printing and fixing. Digital compound machine substantially has the same functions with laser printer and scanners.

The form of laser printing used by digital compound machine is an electrostatic digital printing process. It produces high-quality text and graphics by repeatedly passing a laser beam back and forth over a negatively charged cylinder called a "drum" to define a differentially-charged image. The drum then selectively collects electrically charged powdered ink, and transfers the image to paper, which is then heated in order to permanently fuse the text or imagery. Today, it is accepted that even low-power lasers with only a few milliwatts of output power can be hazardous to human eyesight when the beam hits the eye directly since the laser has thermal effect, light pressure effect, electromagnetic effect and biostimulation. And laser radiation can also cause skin burns with difficulty heals, skin aging. What's more, the electromagnetic radiation released from digital compound machine also easy to cause fetal malformation, miscarriage, premature birth. Therefore, it is better to put a tungsten alloy shielding around the digital compound machine to shield the radiation generated from it.

Tungsten alloy is a tungsten-base alloy with addition of some other elements. According to the research, the radiation shielding performance of a metal material increases with the enhancing of its density, the density of tungsten alloy can reach very high, and therefore it has great radiation shielding ability to effectively absorb and shield radiation released from the digital compound machine, so as avoiding these radiation damaging office workers. With the popularity of digital compound machine in major offices, tungsten alloy radiation shielding for digital compound machine will also serve as a radiation shielding appearing in major offices. 

Tungsten alloy radiopharmaceuticals container is used for containing radiopharmaceuticals which have radioactivity. Radiopharmaceuticals are a group of pharmaceutical drugs or biological agents which have radioactive nuclides. Radiopharmaceuticals can be divided into diagnostic radiopharmaceuticals and therapeutic radiopharmaceuticals, which used for medical diagnosis and treatment, respectively. Diagnostic radiopharmaceuticals mainly include compounds labeled by 99mTc, 201TI, 67Ga, 123I, 75Se, 51Cr and 113mIn whose location and variations in vivo can be detected by γ-ray detector in vitro; while the therapeutic radiopharmaceuticals are compounds labeled by 131I, 32P, 198Au, 186Re, 89Sr, 90Y, 153Sm, 188Re, 117mSn, 117Lu, which achieve the desired therapeutic effect by providing focused radiation exposure to the diseased tissue of a patient. 131I is still the most commonly used radiopharmaceuticals for treatment of thyroid disease.

With the development of nuclear technology in the medical field and the emergence of Nuclear Medicine, the demand for radiopharmaceuticals is also increased significantly. In addition to be used for diagnosis and treatment of thyroid diseases, radiopharmaceuticals are also used for a variety of imaging such as gastric imaging, brain imaging, adrenal imaging, myocardial imaging, liver imaging, heart and great vessels blood pool imaging, and for renal function tests, pulmonary function tests, lung tumor diagnosis, localization of placenta, measurement of red blood cell life span, malignant effusion control, treatment of polycythemia vera and skin disease. Because radionuclides contained in radiopharmaceuticals can emit α rays, β-rays, γ-rays and other rays which have radioactivity, causing harm to human body. Therefore, it is necessary to use a tungsten alloy container for storing radiopharmaceuticals to prevent them from entering into the human body to cause internal exposure by all kinds of ways.

Tungsten alloy radiopharmaceuticals container with great radiation shielding effectiveness can shield radiation generated by radiopharmaceuticals, or prevent them from entering into the human body, to protect staffs and patients from radiation damage. Compared with traditional materials (such as lead), tungsten alloy has a higher density, so as in the case of equal quality, the volume of tungsten alloy is only 1/3 of lead, while the radiation shielding performance is not diminished. And tungsten alloy will not pollute the environment due to its environmental protection feature. 

Tungsten alloy microwave dryer is a new kind of equipment to dry materials by use of microwave technique. Its working principle is acting on the molecular motion. When drying materials, microwave acts directly on the molecule and is converted into thermal energy. Due to the absorbency and penetrability of microwave, water and food can absorb microwave to make themselves heat. Moreover, the uniformity and conformity of heating process prompt the rate of heating to be fast and improve the drying quality greatly.In a word, tungsten alloy microwave dryer has the advantages of quick drying, uniform drying, energy efficient, clean production, easy to automate control and improving product quality.

Tungsten alloy microwave dryer is widely used in food industry, ceramic industry, pharmaceutical industry, chemical materials, laboratory analysis. Such as the drying of powder, grain, slice, strip, plate, small blank, high moisture sticky materials and other materials; activation and regeneration of the catalyst; drying, sterilization and disinfection of sludge and other solid waste and food, medicine, pharmaceutical raw materials;drying, deinsectization and mould proof of rice, flour; solidification of high polymer material. Microwaves are a form of electromagnetic wave with wavelengths ranging from one meter to one millimeter. Long-term exposure to microwave radiation can produce heat damage in human tissues, up to and including serious burns that may not be immediately evident because of the tendency for microwaves to heat deeper tissues with higher moisture content, and will cause neurasthenia, weakened immunity, hemodynamic disorder and other affects. 

It is inevitable to be affected by electromagnetic radiation during the drying process, and induce radiation damage over time. The best solution is tungsten alloy microwave dryer. Tungsten alloy microwave dryer is made up of tungsten alloy material with high density, and thus has good radiation shielding properties, which can efficiently absorb and shield radiation. Therefore, tungsten alloy microwave dryer is capable of shielding microwave radiation, to prevent leakage of microwave radiation, then protect human body from radiation injury. 

During the welding process, arc performance not only connects with power supply unit and the environmental conditions, it also depends largely on the tungsten electrode’s arc performance. Good arc performance directly determines the use and application range of tungsten electrodes. The organizational structure of the tungsten electrode has a certain impact on tungsten electrode’s arc performance. In general, the integrity and uniformity of the tungsten electrode structure will directly affect the arc performance. If tungsten electrodes inside has splitting, delamination, micro-cracks, voids, mezzanine or severe non-uniform grain structure, the arc process is instability. So it will occur arc breaking, arc blasting, drift, and the worst case will cause thermal and electric, conductivity decreased, so that electrode’s local will overheating, melting, deformation, reducing the arc performance. In addition, at high temperatures, the electrode structure is closely related to the chemical composition. At High temperature, the doped rare earth oxides is easily migration, evaporation, dilution resulting in recrystallization coarsening to cause cracks.

Organizational structure and chemical composition of the tungsten electrode can affect their physical and mechanical properties, thus affecting its arc performance. Tungsten electrode as an important part in welding tool should have good physical and mechanical properties, such as, high melting point, high boiling point, low vapor pressure, good thermal conductivity and electrical conductivity, high temperature strength and high recrystallization temperature and creep and other good properties. If the physical property and mechanical properties of the tungsten electrode is defective, then it can result in electrode deformation and melting during the welding, leading arc performance deterioration. Different type rare earth tungsten electrodes have different deformation resistance and high temperature resistance. In general, tungsten electrode doped with two rare earth oxides is better than pure tungsten electrode and tungsten electrode doped with three rare earth oxides is better than tungsten electrode doped with two rare earth oxides.

Tungsten electrode arc performance is affected by physical and chemical property, mechanical properties, chemical composition and organizational structure. The following will analyzes the influence of tungsten electrode chemical composition on arc performance in welding process.

Pure tungsten electrode has high electron work function and it is not conducive to high electron stream emission, so the service life and arc performance is poor, which directly affect the welding performance. In order to improve the disadvantages of pure tungsten electrode, with further research, manufacturers developed rare earth tungsten electrode and multiple rare earth tungsten electrodes. According to the current density formula of physics emission mechanism Je = AT₂exp (-eφ / kT) shows that, in order to reduce eφ (electronic charge), we can add rare earth oxides or other elements in tungsten electrodes to low eφ’s value. Different types of rare earth tungsten electrodes having a particular Je value, so they arc performance are relatively stable.

Tungsten electrodes chemical composition’s type, content, distribution and high temperature characteristics determine the ignition and stability of the arc. In terms of content, taking single rare earth doped tungsten electrode as example, rare earth oxide content is higher, the better the arc performance of the electrodes. In addition, the uniformity distribution and high temperature evaporation and diffusion behavior of rare earth oxides also affected arc performance to some extent. The main reason for arc performance deterioration is caused by doped rare earth’s evaporation and decomposition. Different type rare earth tungsten electrode under different conditions has difference arc performance, tungsten electrode doped with two rare earth oxides is better than pure tungsten electrode and tungsten electrode doped with three rare earth oxides is better than tungsten electrode doped with two rare earth oxides.

Tungsten electrode during operation, the ends of the electrodes will produce ring mushroom nodules, called "Rim" phenomenon. This is because tungsten electrode surface has more added rare earth oxide content than the central portion, in favor of arc in a short time. When the protective gas is mixed with a small amount of O₂ or welding parameters transferred to short-term overload state, it will occurs "Rim" phenomenon. This phenomenon is still under study, some scholars believe that this is due to the tungsten oxide and rare earth oxides evaporation, decomposition, precipitation and segregation at the high temperature to occur dephlegmation and segregation precipitation. In fact, it is the chemical composition of the tungsten electrode changed at high temperatures. "Rim" phenomenon is good for arc in short time, but for a long time will lead to surface additives concentration reduction affected arc electrode performance and increased consumption.

With the increase of the added amount of TiC, its grain refinement, solid solution strengthening effect began to appear, which is beneficial for improving the bending strength of tungsten carbide buttons. And thereafter continue to add TiC, sintered body appeared in the ring structure with non-normal tissue, which is thus the core parts containing lower amounts of solid solution WC and an outer layer containing a high amount of WC solid solution consisting of the ring with will make the structure appear flexural strength decreased more obviously. The variation of fracture toughness is similar to the bending strength.

From the point of view fracture surface, tungsten carbide button after fracture section added TiC is smoother and the distribution is more uniform. And by observing the hard phase of WC and Co binder phase section can be found in WC grains tend to diversify, it also shows that the fracture of the alloy phase is broken along the border and the bonded phase WC grains and binder phase, rarely WC grains through the break, and it is related to the dispersion of fine-grained solid solution with TiC phase of strengthening.

Furthermore, there are some pores in the section, especially the surface of alloy without adding TiC. In the process of solid phase sintering, because of rigid WC skeleton hinder shrinkage during cooling of briquettes contraction and solidification Co generated carbide makes it impossible to completely fill the screen, resulting in the formation of pores shrink tube; on the other hand, uneven distribution and the gas generated during sintering forming agent is one of the reasons. In addition, TiC also has an influence on the routes of cracks expanding. It will have containing and pinning effect on the movements of WC grain boundaries. And owing to a great difference of elastic modulus and coefficient of thermal expansion, the residual stress of TiC and the matrix in the process of sinter cooling, which resulting in cracks in the offset process of moving forward, extending the cracks propagation path.