Mechanization and intelligence promote the rapid development of cemented carbide products for rock drilling

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Release Time :

2016-05-27

In recent years, due to the addition of mechanization and intelligent technology, cemented carbide products for rock drilling have developed rapidly. Its main development trends include the following aspects: ultrafine and nanostructured cemented carbides, high temperature powder-based cemented carbides, functionally graded cemented carbides, binder modified cemented carbides, double-bonded mining cemented carbides, And WC-Co-diamond three-phase composite mining hard materials, etc.

1. Ultra-fine and nano-structured carbide ball teeth: This has been a hot spot in research and development in recent years. As early as the 1990s, related researchers began to study grain refinement to produce submicron, ultrafine and nanostructured cemented carbides. This is because with the continuous refinement of grains, the density, hardness, toughness and wear resistance of cemented carbide materials will be significantly improved. At the same time, the requirements of rock drilling tools for drilling tools are getting higher and higher, especially the high air pressure drilling tools have strict requirements on the wear resistance and toughness of cemented carbide ball teeth, and ultra-fine grained cemented carbide It can fully meet its performance.

2. High-temperature powder-based cemented carbide ball teeth: It is a new process using high-temperature reduction and high-temperature carbonization of raw material powder. The WC powder produced by it has the characteristics of complete grain, high strength, and high particle energy storage. Compared with the traditional vacuum heat treatment process, the average footage ratio of cemented carbide ball teeth is increased by 50%, the rock drilling speed is increased by nearly 100%, the average wear resistance is increased by about 100%, product quality and stability and service life. have been greatly improved.

3. Functionally graded cemented carbide ball teeth: In the process of sintering or heat treatment, a suitable atmosphere is introduced to induce the diffusion of C in the alloy, and through chemical reactions, other group members are rearranged and distributed, resulting in alloy composition and structure along the A certain direction changes to form a gradient structure, and different parts have different functions. Mining functionally graded cemented carbide ball teeth are usually prepared by carburizing low-carbon alloys (introducing CH4, CO and other carbon-containing gases), and the treated ball teeth W and Co are distributed along the diameter direction. This structure endows the column teeth with extremely high wear resistance and toughness. Whether it is a functionally graded structure of carbide DTH drills, roller cone drills or ball-tooth drill bits, the service life is significantly improved.

4. New binder modified cemented carbide ball teeth: Treated with metal melt method (Ni or Si as alloying addition elements), Ni and Si elements can significantly improve the alloy's ability to resist fatigue cracks. In addition, the WC framework was debonded during the infiltration of Ni melt into the sintered alloy, which formed a well-developed WC/Co phase interface in the sintered alloy, reduced grain size, and increased fracture toughness. The results show that the working efficiency is increased by 1.8 times when the cemented carbide tapered rotary drill bit is used for rock drilling.

5. Double-bonded cemented carbide for mining: Compared with ordinary cemented carbide, cemented carbide phase pellets are not composed of hard compounds, but sintered alloy pellets, that is, sintered pellets are mixed with metal binder. And the secondary sintering is carried out, so that the fracture toughness can be greatly improved without reducing the hardness.

6. WC-Co-diamond three-phase composite mining hard material: using high temperature and high pressure synthesis, the powder/polymer mixture is extruded into green compacts, and then consolidated by high temperature and high pressure diamond synthesis. The main advantages are that the thermal expansion and elastic mismatch stress are reduced, and the diamond shedding is enhanced; the diamond-enhanced surface improves the wear resistance; the WC-Co-diamond composite surface has excellent fracture toughness, enhanced wear resistance, and improved service life. V