The production process and forming process of tungsten carbide rods

There are two forming methods for the production of tungsten carbide round bars: one is extrusion, and extrusion is a suitable way to produce long bars. It can be truncated to any length desired by the user during the extrusion process. However, the overall length cannot exceed 350mm. The other is compression molding, which is a suitable way to produce short bar stock. As the name suggests, cemented carbide powder is pressed into shape with a mold.

Cemented carbide has a series of excellent properties such as high hardness, wear resistance, good strength and toughness, heat resistance, corrosion resistance, especially its high hardness and wear resistance, which remains basically unchanged even at a temperature of 500 °C, and still has a high hardness at 1000 °C. Tungsten carbide is widely used as tool materials, such as turning tools, milling cutters, planer cutters, drills, boring cutters, etc., for cutting cast iron, non-ferrous metals, plastics, chemical fibers, graphite, glass, stone and ordinary steel, and can also be used to cut heat-resistant steel, stainless steel, high manganese steel, tool steel and other difficult materials wet grinding (ball mill, drying cabinet, Z-mixer, granulator---), pressing (with side pressure hydraulic press or extruder), --- sintering (degreasing furnace, integrated furnace or HIP low pressure furnace).

The raw materials are wet grinding, drying, glue doping, then drying and stress reduction after molding or extrusion, and finally forming the final alloy blank by debinding and sintering.

The disadvantage of round bar extrusion production is that the production cycle is long. Squeezing small diameter round bars below 3mm and breaking the two ends will waste a certain amount of material. The longer the length of the carbide small diameter round bar, the worse the straightness of the blank. Of course, straightness and roundness problems can be improved by cylindrical grinding at a later stage.

Another is compression molding, which is the way short bar stock is produced. As the name suggests, it is the mold that presses the cemented carbide powder into shape. The advantage of this carbide bar forming method is that it can be formed in a single pass and reduces scrap. Simplify the wire cutting process and eliminate the dry material cycle of the extrusion method. The above shortened time can save customers 7-10 days.

Strictly speaking, isostatic pressing also belongs to compression molding. Isostatic pressing is the ideal forming method for the production of large and long tungsten carbide round bars. Through the upper and lower piston seals, the pressure pump injects the liquid medium between the high-pressure cylinder and the pressurized rubber, and the pressure is transmitted through the pressurized rubber to make the cemented carbide powder pressed into forming.