1. Performance
Since the tungsten needle is produced from pure tungsten or tungsten alloy, it has excellent physical and chemical properties of pure tungsten or tungsten alloy, such as high density, high melting point, high hardness, high tensile strength, good wear resistance, ductility Good thermal conductivity, good thermal conductivity and long service life.
2. Type
According to different design shapes, tungsten needles can be divided into round rod-shaped tungsten needles and pointed tungsten needles. Round rod-shaped tungsten needles are slender cylindrical pure tungsten or tungsten alloys, mainly used as electrodes for argon arc welding. Precautions for argon arc welding: the welding current should not be too large, and the distance between the tungsten needle and the workpiece should not be too far. Otherwise, it is easy to melt or burn the electrodes. Pointed tungsten needles can be simply understood as pure tungsten or tungsten alloys with sharp points at one or both ends, and are mainly used as instrument probes, such as digital four-probe testers. The distance between the four tungsten needles of the digital four-probe tester cannot be too long or too short, and the function of each tungsten needle is different.
3. Production Process
There are two main production processes for tungsten needles: one is the metal injection process, and the other is the wire drawing process.
Metal injection process: first mix the solid powder and organic binder evenly, then use the injection molding machine to inject the mixed raw materials into the mold cavity in a heated and plasticized state to solidify and solidify, and then remove the binder in the molding blank by chemical or thermal decomposition , and finally sintered into a dense product, and then surface treated to obtain the final tungsten needle product.
Wire drawing process: Heating the metal raw material to plasticity, then stretching to the required diameter, and finally shearing, cooling and polishing.
4. Application
Tungsten needles have excellent wear resistance, heat resistance and durability, so they can be widely used in metal welding and engraving, electronic probe devices, precision instrument probes, glass processing and single particle processing and other fields.
5. Precautions
Its tip is easy to bend or break, so it is necessary to pay attention to the special needle seat or storage box during storage and use, and to use less for processing hard materials, which can also continuously increase the service life of tungsten needles.
