How Does Tungsten Needle to Obtain a Precise Tip Radius?

Tungsten needle is a kind of tungsten rod with sharp ends. Usually, it is made of high-density tungsten metal so that it can be widely used in many fields. For its production, it adopts powder metallurgy, but this method is not enough when very sharp tips are required. 

As one of the core components of the field emission electron microscope, the performance of the field emission electron source determines the main electron optical performance parameters in the field emission electron microscope, which includes the emission angular current density of the electron gun, the total emission current of the electron beam and the stability of the electron beam, etc.

In order to meet the requirements of high brightness, large beam current, good beam stability, and small electron energy dispersion of the field emission electron source, it is necessary to sharpen the tip of the single crystal tungsten wire of the field emission electron source. Generally, the tip radius is required between 0.5-1.0μm.

The researchers with the patent number CN102339704B proposed a preparation method for obtaining a field emission electron source needle with a radius between 0.5-1.0 μm. Its specific operation is as follows:

1) Pour a certain amount of sodium hydroxide powder into a beaker with a balance, and then add a certain amount of pure water to prepare a corrosion solution with a concentration of 3-5mol/L; 2) Put the prepared corrosion solution from the U-shaped One end of the tube is poured into the U-shaped tube, and an electrode is inserted; 3) Fix the ceramic seat welded with the single crystal tungsten wire to the fixed frame with the micrometer head, and adjust the micrometer head so that the single crystal tungsten wire is immersed in the container. Put a certain distance below the liquid surface of one end of the U-shaped tube containing the corrosive liquid, and put an electrode under the liquid surface of the other end of the U-shaped tube containing the corrosive liquid; 4) Connect the connecting wire with the electrode clip and the switch to the The signal source is connected, connect one electrode clamp to the electrode on the ceramic seat for welding single crystal tungsten wire, and connect the other electrode clamp to the electrode at the other end of the U-shaped tube; 5) Turn on the signal source and adjust the signal source required for corrosion Parameters; 6) Start the switch on the connecting wire to start corrosion; 7) After the corrosion is over, turn off the switch; 8) Adjust the micrometer head so that the tungsten wire on the filament ceramic seat completely exits the corrosion solution.

Compared with other manufacturing methods, the AC electrochemical corrosion method is easier to be adopted by everyone, mainly because it has many controllable parameters, high corrosion precision, and good product stability.

If you have any inquiry of tungsten needles, please feel free to contact us:

Email: sales@chinatungsten.com/sales@xiamentungsten.com

Tel.: +86 592 5129696/+86 592 5129595

Fax: +86 592 5129797

Scan QR code of Chinatungsten WeChat platform to follow up the daily latest price and market of tungsten, molybdenum and rare earth.

New Production Method for Diamond Wire Saw

Diamond wire saw, also known as diamond wire, refers to a cutting wire that fixes diamond abrasives on metal wires by electroplating or resin bonding. It is mainly used to cut high-hard and brittle materials such as single crystal silicon, polycrystalline silicon, sapphire, magnetic materials, and hard alloys, etc.

Compared with free abrasive wire saws, it has the advantages of higher processing efficiency, lower energy consumption, and better cutting quality; compared with circular saws and band saws, it can not only change the cutting direction more flexibly, but also process more complex geometries. However, this does not mean that the wire saw has no disadvantages. The current wire saws that use carbon steel wire as the busbar/base material have the disadvantages of large wire diameter, high wire breakage rate and short service life. Therefore, in order to make up for the shortcomings of the existing wire saws, manufacturers began to use doped tungsten wires to replace high-carbon steel wires as the base material of diamond wires.

For the production of diamond wire saw, the researchers with the patent number CN113275659A proposed a new production method, the process is: (1) Optimal black tungsten wire, which goes through wire setting→three-stage electrolytic polishing→water washing→drying →take up the wire to prepare the silver-white metallic luster tungsten wire; (2) The tungsten wire treated in step (1) is discharged in turn→secondary degreasing→pickling→impact nickel→sanding→sand fixing→heat treatment→take up the wire, and you can prepare a tungsten diamond wire saw with a wire diameter of 30~40um.

The specific steps are as follows: the diamond wire busbar is a tungsten wire, and its surface is etched with "swallowtail" pits, which are formed by three-stage electrolytic polishing; each stage of electrolytic polishing in the three-stage electrolytic polishing. The equipment for each level of electrolytic polishing in the three-level electrolytic polishing consists of a working tank, a corrugated profiling plate cathode plate, an ultrasonic vibration plate, an anode guide wheel, a circulation tank, a heating pipe, a circulating liquid pump, a filter, and a plate heat exchanger, high-frequency DC switching power supply; the impact nickel layer is filled with pits and plated on the surface of the bus bar, the impact nickel layer and the bus bar form a "dovetail" structure, and the upper sand layer is plated on the surface of the impact nickel layer and consolidated with diamond particles , the surface of the upper sand layer is also coated with a layer of sand-fixing sand layer.

If you have any inquiry of tungsten wire, please feel free to contact us:
Email: sales@chinatungsten.com/sales@xiamentungsten.com
Tel.: +86 592 5129696/+86 592 5129595

Fax: +86 592 5129797

Scan QR code of Chinatungsten WeChat platform to follow up the daily latest price and market of tungsten, molybdenum and rare earth.

Tungsten Sheet Price in Early January 2023

Φ100x0.3mm tungsten sheet price is 4.60 USD/PC in the first half of January 2023, EXW XIAMEN, CHINA. 

Tungsten sheets can be as thin as 0.01mm or as thick as 127mm, with widths typically ranging from 10mm to 800mm. They can be used in many different applications and is valued for its corrosion resistance, ability to withstand extremely high temperatures, and ability to create rigidity and hardness when combined with other metals in the alloy.

Tungsten is used in the aerospace, research, building materials and light bulb industries. It is the predominant metal in electric furnace heating elements, as well as in any assembly where high pressure/high temperature environments are expected. Sheets made of tungsten are commonly used in furnace construction, but are also important for making parts for the electronics and semiconductor industries, and can be found in a variety of lighting, vacuum plating, electronic vacuums and shielding.

If you have any inquiry of tungsten sheet, please feel free to contact us:

Email: sales@chinatungsten.com/sales@xiamentungsten.com

Tel.: +86 592 5129696/+86 592 5129595

Fax: +86 592 5129797

Scan QR code of Chinatungsten WeChat platform to follow up the daily latest price and market of tungsten, molybdenum and rare earth.

Lanthanated Tungsten Electrode Price in Early January 2023

Ø3.2x175mm lanthanated tungsten electrode price is 1.90 USD/PC in the first half of January 2023, EXW XIAMEN, CHINA. 

Wl20 electrodes contain at least 1.7% to 2.2% lanthanum for excellent arc starting, low burnout rate, good arc stability and excellent re-ignition characteristics. They are ideal if you want to optimize your welding capabilities. They can work well on either AC or DC electrode negatives with tips, or they can be used with AC sine wave power supplies. The tungsten electrode adding with rare earth element lanthanum holds sharp tips well, which is an advantage for welding steel and stainless steel on DC or AC from square wave power sources.

If you have any inquiry of lanthanated tungsten electrode, please feel free to contact us:
Email: sales@chinatungsten.com/sales@xiamentungsten.com

Tel.: +86 592 5129696/+86 592 5129595

Fax: +86 592 5129797

Scan QR code of Chinatungsten WeChat platform to follow up the daily latest price and market of tungsten, molybdenum and rare earth.

How to Produce High-precision Tungsten Foil?

Heat shields, heating elements and vacuum furnace supports are made of tungsten foil. The foil is thin and is ideal for embedding in laminates, other metals and glass; it is made of mental tungsten and can be used in high temperature vacuum furnaces, coatings, electronic and semiconductor components.

How to produce the thin foil? 

Compared with the coating deposition method, the rolling method is more suitable for the production of tungsten foil, mainly due to the advantages of higher hardness, surface finish and mechanical strength, especially the density can be close to the theoretical density of tungsten. However, the working efficiency of the commonly used four-high rolling mill in industry is extremely low, and the production equipment is easily damaged due to the long-term high rolling tonnage. In order to solve the above technical problems, the researchers with the patent document serial number 17017104 proposed a rolling method of high-precision W foil. The specific steps are:

1)Cut the tungsten plate (thickness 0.09mm~0.11mm) into the same size of plate; 2) Place the nickel sheet as a welding sheet between the tungsten sheets obtained in the adjacent step 1), and use a spot welding machine for spot welding to obtain a welded tungsten sheet; the number of tungsten sheets is 2 to 4 pieces, and the nickel sheet is placed on one end of the tungsten plate along the length direction, and the width direction of the nickel plate is consistent with the length direction of the tungsten plate; 3)Perform multi-pass rolling on the welded tungsten plate obtained in step 2) to obtain a rolled foil; the tonnage of the rolling equipment used in the multi-pass rolling is 60t-120t, and the roll crown is 0.04mm-0.06 mm; when the total processing rate of multi-pass rolling exceeds 40%, the rolled welded tungsten sheet is annealed; the thickness of the rolled foil is 0.04mm to 0.08mm; 4) Cut off the welded end of the rolled foil obtained in step 3), and then separate the layers in the rolled foil to obtain a foil; the thickness of the foil is 0.018mm to 0.023mm, and the thickness tolerance ± 0.0015mm, width 175mm ~ 180mm.

The advantage of this rolling technology is that spot welding the tungsten plate of the same size with the nickel plate as the welding piece not only ensures the melting of the nickel plate to the welding of the tungsten plate, but also avoids the brittleness of the tungsten plate, which is beneficial to the later stage. The first rolling was carried out smoothly, and 2 to 4 pieces of foil with uniform size were produced at one time, which solved the problem of low efficiency of single rolling and greatly improved the production efficiency; at the same time, small-tonnage rolling equipment was used to carry out multi-pass rolling makes the rolled W foil uniform in thickness and bright in surface, which effectively improves the precision of W foil. 

If you have any inquiry of tungsten foil, please feel free to contact us:

Email: sales@chinatungsten.com/sales@xiamentungsten.com

Tel.: +86 592 5129696/+86 592 5129595

Fax: +86 592 5129797

Scan QR code of Chinatungsten WeChat platform to follow up the daily latest price and market of tungsten, molybdenum and rare earth.