What is cemented carbide

What is cemented carbide

    Cemented carbide is made by powder metallurgy with one or several refractory carbides (tungsten carbide, titanium carbide, etc.) powder as the main component, adding metal powder (cobalt, nickel, etc.) as a bonding agent, Alloy. It is mainly used to manufacture high-speed cutting tools and cutting tools for hard and tough materials, as well as cold work molds, measuring tools and high wear-resistant parts that are not subject to impact and vibration.

The characteristics of cemented carbide

1. High hardness, wear resistance and red hardness

The hardness of cemented carbide at room temperature can reach 86-93HRA, which is equivalent to 69-81HRA. It can maintain high hardness at 900-1000°C and has excellent wear resistance. Compared with high-speed tool steel, the cutting speed can be 4-7 times higher, the service life is 5-80 times longer, and hard materials with a hardness of up to 50HRA can be cut.

2. High strength and elastic modulus

The compressive strength of cemented carbide is as high as 6000MPa, and the modulus of elasticity is (4-7)*105MPa, which is higher than that of high-speed steel. But its bending strength is low, generally 1000-3000MPa.

3. Good corrosion resistance and oxidation resistance

Generally, it has good resistance to atmospheric, acid, alkali and other corrosion, and is not easy to oxidize.

4. Small linear expansion coefficient

When working, the shape and size are stable.

5. Shaped products are no longer processed and reground

Due to the high hardness and brittleness of cemented carbide, it is no longer necessary to cut or regrind after powder metallurgy forming and sintering. When special reprocessing is required, only electrical processing such as EDM, wire cutting, electrolytic grinding or special grinding wheel grinding can be used. cut. Products of a certain specification usually made of cemented carbide are brazed, bonded or mechanically clamped on the cutter body or mold body for use.

Application of cemented carbide

1. Tool material

Cemented carbide has the largest number of tool materials, which can be used to make turning tools, milling cutters, planers, drills, etc. Among them, tungsten-cobalt cemented carbide is suitable for the processing of ferrous metals and non-ferrous metals with short chips and the processing of non-metallic materials, such as cast iron, cast brass, bakelite, etc.; tungsten-titanium-cobalt cemented carbide is suitable for steel and other ferrous metals. Chip processing. Among similar alloys, those with more cobalt are suitable for rough machining, and those with less cobalt are suitable for finishing. The machining life of general-purpose cemented carbide for difficult-to-machine materials such as stainless steel is much longer than that of other cemented carbides.

2. Mould material

Cemented carbide is mainly used as cold drawing die, cold punching die, cold extrusion die, cold forging die and other cold working dies.

3. Measuring tools and wear parts

Cemented carbide is used for wear-resistant parts such as wear-resistant surface inlays and parts of measuring tools, precision bearings of grinders, guide plates and guide rods of centerless grinders, and center of lathes.