Mechanization and intelligence to promote the rapid development of hard alloy products for rock drilling
Release time:
2016-05-27
In recent years, due to the addition of mechanization and intelligent technology, the development of hard alloy products for rock drilling is very rapid. Its main development trends include the following aspects of ultrafine and nanostructured cemented carbide, high temperature powder-based cemented carbide, functionally graded cemented carbide, binder-modified cemented carbide, double-bonded cemented carbide, and WC-Co-diamond three-phase composite mining hard materials.
1. Ultra-fine and nano-structured carbide ball teeth: This has been a hot topic of research and development in recent years. As early as the 1990 s, relevant researchers have begun to study the refinement of grains to produce submicro, ultrafine and nanostructured cemented carbides. This is because with the continuous refinement of grain, the density, hardness, toughness and wear resistance of cemented carbide materials will be significantly improved. At the same time, the requirements of rock drills on drilling tools are getting higher and higher, especially high wind pressure drilling tools have strict requirements on the wear resistance and toughness of cemented carbide ball teeth, and ultrafine-grained cemented carbide can fully meet its performance.
2. High-temperature powder-based cemented carbide ball teeth: It is a new process of high-temperature reduction and high-temperature carbonization of raw material powder. The WC powder prepared by it has the characteristics of complete grain size, 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, and the product quality, stability and service life have been greatly improved.
3. Functionally graded cemented carbide button: in the process of sintering or heat treatment, the diffusion of C in the alloy is induced by the appropriate atmosphere, and the other members are rearranged and distributed through the chemical reaction, thus causing the alloy composition and structure to change along a certain direction, forming a gradient structure, and different parts have different functions. The functional gradient carbide ball teeth for mining are usually made by carburizing low-carbon alloy (through CH4, CO and other carbon-containing gases), and the treated ball teeth W and Co are distributed along the diameter direction. This structure gives the column teeth extremely high wear resistance and toughness, whether it is a functional gradient structure of the carbide down-the-hole drill, tooth wheel drill or ball tooth drill life has been significantly improved.
4. New binder modified carbide ball teeth: treated by metal melt method (Ni or Si as alloying added elements),Ni and Si elements can significantly improve the ability of the alloy to resist fatigue cracks. In addition, during the infiltration of the Ni melt into the sintered alloy, the WC skeleton is disbonded, which forms a developed WC/Co phase interface in the sintered alloy, reduces the grain size, and thus increases the fracture toughness. The results show that the working efficiency of the carbide conical rotary drill bit is increased by 1.8 times.
5. Double cemented carbide: Compared with ordinary cemented carbide, cemented carbide phase pellets are not composed of hard compounds, but composed of sintered alloy pellets, that is, sintered pellets are mixed with metal binder and secondary sintering, so that the fracture toughness is greatly improved without reducing the hardness.
6.WC-Co-diamond three-phase composite hard material for mining: using high temperature and high pressure synthesis, the powder/polymer mixture is extruded into green compacts, and then consolidated with high temperature and high pressure diamond synthesis. Its main advantage is to reduce the thermal expansion and elastic mismatch stress, so that the diamond shedding enhanced; diamond enhanced surface, improved wear resistance; WC-Co-diamond composite surface fracture toughness excellent, wear resistance, increased service life.
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