Corrugated Roll Tungsten Carbide Cobalt Coating Reinforcement

corrugated roll tungsten carbide cobalt coating reinforcement image

Thermal spraying technology is a key technology in the field of surface modification. As a wear-resistant and corrosion-resistant coating, tungsten carbide/cobalt coating is widely used in aerospace, metallurgy, machinery and other fields because of its high hardness and good toughness. Compared with hard chromium plating, thermal sprayed WC-Co coating has obvious advantages in wear resistance, corrosion resistance, fatigue resistance and so on, and has the advantages of rapid preparation and less environmental pollution.

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Tungsten Oxide Electrochromic Film

pure yellow tungsten power

A variety of color-changing films can be seen everywhere in life, and the materials for making color-changing films are very wide. One of the new materials is the tungsten oxide electrochromic film.

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Researchers Have Developed A New Tungsten Oxide Nanofiber Membrane

tungsten oxide powder picture

The life on earth is inseparable from the sun. With the development of science and technology, people realize that sunlight provides enough renewable green energy to achieve higher solar-thermal energy conversion efficiency and achieve more efficient water evaporation performance. The topic of photothermal materials----tungsten oxide nanofiber membranes is constantly being explored.

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Advantages of Nano Tungsten Oxide Insulating Glass

tungsten oxide powder picture

Nano tungsten oxide heat-insulating glass is one kind of coated glass, which is produced through mixing a mixture of 5-10nm nano tungsten oxide and indium-phosphide oxide with resin and diluent, and then coat on the glass surface. The new coated glass has the advantages of good heat insulation performance, high transparency and good anti-UV effect, and is widely used in architectural glass curtain wall, vehicle and ship glass and other industries.

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Tungsten Oxide Insulating Glass Could Protect Children's Skin Health

tungsten oxide

Tungsten oxide insulating glass can effectively prevent ultraviolet rays come into the room, and protect people skin health, especially for infants’ and children’ skin health.

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Tungsten Oxide Insulating Glass Makes Eco-friendly Society

tungsten oxide powder picture

Tungsten oxide insulating glass is a new type of eco-friendly building material. During the glass producing process, a proper proportion of rare metal oxide tungsten trioxide is added to make the glass have better thermal insulation performance, and barrier the ultraviolet rays and infrared ray from the sun. In Europe and America, it has become the industry standards to use the thermal insulating glass in the architecture project. The increasingly energy crisis has got the Chinese government attention, and the government cast the proposal to build eco-friendly society through using the eco-friendly and energy-saving materials in the different industries.

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Mo Crucible and Assembling Mold

Molybdenum Crucible picture

In order to save the cost, the production of Mo crucible mainly uses the assembling mold with the method of powder metallurgy. 

The feature of Mo crucible is that the part is composed of wall cylinder and the hypo-cone.

The ratio of height to thickness of the wall cylinder is close to 8. It is easy to generate the cracks on the surface during the manual pressing. Therefore, we use the assembling molds and adopt the method of powder metallurgy to solve this problem. Due to the friction between powders and between powder and molds, the pressure loss occurs during the pressing. We adopt the double-direction pressing in order to increase the density of hypo-cone and ensure the uniformity of green compact density. After finishing the first pressing, the die cushion will be removed and the second pressing starts. In order to facilitate the demolding of the hypo-cone of the Mo crucible from the base, the base is composed of three vertically and equitably separated block (include the die block, the upper die punch and the wall cylinder of the Mo crucible).

Molybdenum Crucible picture

The advantages of using the assembling molds are listed as below:

1.0 The use of assembling mold for pressing can help control the density of various parts of Mo crucible, and ensure that the density of parts of the parts are consistent.Therefore, it improves the performance of the process.

2.0 The adoption of double-direction pressing compensates for the low density caused by the pressure loss and increases the density of every part.

3.0 The base of assembling mold is composed of three parts which can solve the problem that the hypo-cone part is not easily demolded. The application of assembling mold is one of the effective ways to produce the Mo crucible. The promotion of this method can show the feature of powder metallurgy production and accelerate the development of powder metallurgy industry.

Iridium Tube Function- Production of Tungsten Iridium Stream Mouth

Iridium tube picture

Iridium is the element in Ⅷseries. The Iridium is the main product of Iridium which is characterized by high melting point, boiling point, hardness, density, elastic modulus and corrosion resistance and low Poisson’s ratio. One of its main application is to combine with tungsten in order to produce tungsten iridium stream mouth. 

Iridium tube picture

The iridium tube owns the following properties:

1.0 High corrosion resistance

2.0 High erosion resistance of silicate at elevated temperature

3.0 High erosion resistance of the melting reagent

4.0 Good plasticity at over 1600 centigrade

5.0 High elastic modulus, low Poisson’s ratio and low plasticity at low temperature

6.0 High melting point, boiling point, hardness and density

7.0 Good ductility, electrical conductivity and heat conductivity

Tungsten iridium stream mouth is the combination of tungsten basal body and the iridium tube. Its properties (such as the wear resistance, hardness, strength and so on) got a further improvement so that guarantees the uniformity of products. It is these properties that make it an indispensable component in today's high-tech crystal industry. The density of the tube is not less than 21.00g/cm3, and the purity of iridium is not less than that of SM-Ir99.95 iridium powder in the GB/T 1422. The degree of curvature is not more than 5mm/m, and its internal and external surfaces are smooth without the defects, such as burr, crack and so on.

The stream mouth is widely applied the metallurgy of rare earth metals, the heater of the induction furnace, the smelting of the silex and so on.

Type of Hot Runner Nozzle System

TZM picture

Hot runner applied to the injection mold during the production of the TZM alloy is the assembly of heating components that put the melting plastic into the cavity.

Generally, the hot runner systems can be divided into single-headed hot runner system, multi-headed hot runner system and valve-regulated hot runner system. The single-headed hot runner system includes one nozzle, the nozzle head, temperature controller and so on. 

Single-headed hot runner system:

The structure of its injection molds is relatively simple. During the production of TZM alloy, the molten plastic is poured into the nozzle connecting plate from the nozzle to the nozzle head and then injected into the mold cavity. It is necessary to control the sizes (d, D, L) and adjust the thickness of the nozzle connecting plate so that the fixing plate of fixed mold can press the end of the nozzle connecting plate to control the axial displacement. The same purpose can be achieved by directly using the nozzle of the injection machine against the end of the nozzle connecting plate.

TZM picture

Multi-headed hot runner system:

The structure of its injection molds is relatively complicated. During the production of TZM alloy, the molten plastic is poured into the nozzle connecting plate from the nozzle to the nozzle head and then injected into the mold cavity. The nozzles and fixed mold plates have matching requirements for radial dimension D1 and axial dimensional limit requirements. The nozzle head and the fixed mold insert have a matching requirement for radial dimension d to ensure that the molten plastic does not overflow to the non-cavity part, and the hardness of the fixed mold insert is required to be hardened by about 50HRC.

Valve-regulated hot runner system:

Compared with other normal hot runner systems, the plastic mold structure of this system is the most complicated because it has an additional valve needle transmission device which controls the opening and closing movement of the valve needle. The transmission device is equivalent to a hydraulic cylinder, which is connected with the mold by the hydraulic device of the injection machine to form a hydraulic circuit. As a result, it realizes the opening and closing movement of the valve needle and controls the molten plastic injection into the cavity.

Czochralski Method and Crystal Growth Furnace

Molybdenum Crucible picture

Czochralski method is abbreviated as CZ method. This method is mainly used to pull crystals from the solution. In the crystal growth furnace, molybdenum crucible is mainly used as a carrier. In 1964, this method was first applied to the growth of sapphire single crystals, successfully growing the sapphire crystals with higher quality.

The steps of Czochralski method are listed as below:

1.0 To heat the raw material to the melting point. Owing to difference in temperature, it forms the super-cooling. Therefore, the melt then begins to solidify on the surface of the seed crystal and grow the single crystals which own the same crystal structure with the seed crystal. Meanwhile, the seed crystal is pulled up at a slow speed, and the molten metal gradually solidifies on the solidification interface of the seed crystal, thereby forming an axisym metric single crystal ingot.

By controlling the speed of pulling, it grows the crystal neck, head, body and tail. 

2.0 When the crystal neck has been formed, the speed of pulling needs to slow down in order to make the diameter of crystal increase to the needed length. This step is the growth of crystal head. 

3.0 When the diameter of crystal increases to the needed length, the pulling speed should be uniform. The diameter of the crystal at this step is fixed. This is the part of crystal body.

4.0 After the growth of crystal body, the crystal ingot should be removed from the molten metal. At this time, the pulling speed begins to accelerate. The diameter of the ingot will decrease until the ingot turns into a point and is separated from the molten metal. This step is the growth of tail. The purpose is to prevent from generating the thermal stress during the quick separation between the ingot and the melt. The thermal stress which is generated during the separation will leads to the defects of the ingot, such as dislocation, slip line and so on.

Molybdenum Crucible picture

It is convenient for us to observe the growth of crystal if we adopt CZ method. The crystal grows on the liquid surface without the influence of Mo crucible. In addition, this method can decrease of the stress of crystals and make people use the seed crystal orientation more conveniently. It helps grow crystals with higher quality at a faster rate.

 

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