The researchers use two kinds of spray gun (internal and external powder feed) to observe the structure and properties of tungsten copper heat sink. It can be found that in the internal powder feeding conditions, W content of tungsten copper composite material is higher than the content of external powder feed. This is due to internal feed powder is powder being ejected before the gun are all located in the plasma flame, part of the W particle is melted, melted and un-melted W particles, and the molten copper solution together is sprayed into the substrate, so that easy obtain raw material powder composition approximating tungsten copper composite material; while in the process of external powder feed, he trajectory of the powder particles are not entirely consistent with the plasma flame, which can only make a fraction of smaller particle size of the W particles melt, and a lot without melting of W particles are difficult to be deposited, so the W collected rate decrease.

Besides, at internal powder feeding conditions, only a small amount of cuprous oxide can be detected, which indicates the impact of power in copper oxidation is not obvious. This is due to the internal powder feeding only a very small amount of oxygen is brought into a powder particle flow, thereby largely avoiding the oxidation of copper; by contrast, in the same power, a large number of external powders feed oxygen into the powder particles flow and exacerbates the copper oxide. With the power increase, the plasma flame temperature also increases, the oxidation of copper increased significantly. Overall, plasma spraying uses plasma arc, which compared with free arc has fine arc, high current density, and high degree of gas ionization. So it has many advantages, such as high temperature, high energy concentration, excellent arc stability, which is the ideal material for tungsten copper heat sink.

With the rapid development of science and technology, integrated in the microelectronics industry sectors related electronic products have become more sophisticated, the corresponding energy consumption also increased. So it places higher demands on heat sink properties, which not only required high density and strength, but also has excellent electrical conductivity, thermal conductivity and low coefficient of thermal expansion. Tungsten copper is composed of W with high hardness, high density, high strength, high melting point and low coefficient of thermal expansion and Cu with perfect electrical and thermal conductivity so that it can be an ideal material for heat sink. Furthermore, the properties of tungsten copper heat sink can be improved by the adjustment of W and Cu content.

Since there is a great difference in physical and chemical properties between W and Cu, which has 2000℃ difference in melting point. Both of them do not form a compound or solution, so it is a kind of typical pseudo alloy. Therefore, it is difficult to achieve by common pressed and sintered, the infiltration is the best way. But infiltration is easy to form pores certain deficiencies and to bring some difficulties to the subsequent processing. Plasma spraying is a strengthening of the material surface and surface-modified new multi-purpose precision spraying techniques. It uses plasma arc drove by DC as the heat source and has the following characteristics:

1. Ultra-high temperature characteristics, suitable for spraying refractory material;

2. High particle injection rate, the coating is dense and has higher bonding strength;

3. In the process of spraying, inert gas used as the shielding gas so that the coating material difficult to be oxidized.

Plasma spraying technique can make the surface of the substrate with a high temperature oxidation, thermal insulation, anti-friction, wear and corrosion, insulation, radiation protection and sealing properties, which can heat metal, alloy and ceramics to molten or semi-molten state and spray to the surface after pretreatment at high speed to form a firmly attached layer. In addition, plasma spraying also can be used in medical field, the coating layer of a few microns in artificial bone surface coating can achieve enhanced affinity for artificial bone and the strengthening effect.

Tungsten alloy radiation shielding for IDC room is a radiation shielding used to shield electromagnetic radiation generated by IDC room. IDC room, also known as Internet data center, is the standardized telecom room established by the telecom department through utilizing the existing bandwidth resources and Internet communications lines. With the evolving needs of Internet, IDC room rapidly develops into a vital part of China's Internet industry in the new century, to provide professional server rental managed services and related value-added services for the media, enterprises, Internet content providers, government, business or web server group. Therefore, the enterprises or government agencies no longer need to establish their own IDC room,lay the expensive communication lines, and hire network engineers with the use of IDC server hosting business.

Due to IDC room equipments will release large amounts of electromagnetic radiation which is harmful for human body, staffs can use tungsten alloy radiation shielding for IDC room to shield radiation. Electromagnetic radiation has thermal effects, non-thermal effects and cumulative effects on the human body. According to experts, electromagnetic radiation  more than 2 gigahertz will cause people to suffer from diseases, such as skin disease, cardiovascular disease, vitiligo, psoriasis, allergic purpura and diabetes, and lead to eyelid edema, bloodshot eyes, stuffy nose, runny nose, sore throat discomfort, or systemic skin urticaria, eczema, itching. Long-term and excessive electromagnetic radiation will also damage human reproductive, nervous and immune system, changing blood, lymph and cell protoplasm, causing fetal malformation or spontaneous abortion.

Tungsten alloy radiation shielding for IDC room mainly uses tungsten heavy alloy. According to the research, the radiation shielding performance of a metal material is closely related to its density, the radiation shielding ability increase with the increasing of density. Due to the high density of tungsten alloy, tungsten alloy radiation shielding for IDC room thus has high radiation shielding properties, which can effectively shield the electromagnetic radiation generated by the IDC room equipment, to reduce the radiation damage on staffs. Moreover, tungsten alloy is a harmless and non-toxic material that will not produce harmful substances or pollute the environment. 

Steel bonded carbide has many advantages, compared with conventional steel, it has higher hardness, wear resistance, hardenability (the ability to obtain the hardened layer depth of quenching); compared with tungsten carbide, it has excellent machinability (such as turning, milling, planing, etc.,), heat treatable and weldable. It also by forging changes its dimensions and internal organizational structure to improve performance, which is generally not available in tungsten carbide. By electrical welding, insert welding, surfacing, vacuum welding, steel bonded carbide can meet a variety of application needs.

Steel bonded carbide also has a smaller proportion of high specific strength, good self-lubricating, high natural frequency and damping characteristics, a significant damping effect. Wherein the circular SiC grains is working with the workpiece surface forms rolling friction, so as to effectively avoid the adhesion of wear and abrasion wear. Combined with the advantages of steel and tungsten carbide, steel bonded carbide has a wide scope of application, which can be used in military materials, marine, aerospace materials, high temperature and corrosion-resistant parts, wear parts of damping, mold material, crushing mining tools, measuring instruments and some fields has special requirements of materials proportion and overall performance.

The machining principle of steel bonded carbide is low cutting rate, accurate control of cutting depth and length, do not add any coolant (except grinding process). If we violet these principles, the surface of steel bonded carbide will be hardened, which hiders the machining process. Material of the tool in the milling process usually uses the high-speed steel and carbide; drilling process should not add coolant to ensure that no oil and drill using medium voltage feed and promptly chip to prevent debris from wear and tear on the drill bit; grinding with high hardness, good self-sharpening diamond grinding wheel 120 #, but should pay attention to the amount of coolant; after quenching, steel bonded carbide will easily crack in the process of electrical machining. In order to prevent the cracks from appearing or extending, it should be extending the annealing time until the stress relief and using quenching or isothermal quenching process.