Researchers at MISIS University have successfully completed testing of a new carbide tool equipped with mining cutters for coal mining. Its resource reserve is twice as long as existing analogues. With the support of an industrial partner, the equipment successfully passed tests at a Kuzbass coal mine. The creation of such a tool became possible due to the improvement of the properties of the carbide, which reduced wear and critical deformation of the working elements of mining equipment.
Carbide tools are widely used in metallurgy and mechanical engineering for metal processing, in the mining industry for mineral extraction, in the oil and gas industry for well drilling, as well as in the construction industry.
Carbide alloys are composite materials consisting of a carbide skeleton and a metal binder based on iron group metals. During metalworking or drilling of rocks, carbide tools are subjected to high mechanical loads and intensive wear, and the working surfaces of the tool heat up to 1000 ° C. Such extreme operating conditions naturally lead to equipment degradation and critically affect its performance.
“Deformation of cutting edges can significantly reduce the service life of the tool. Therefore, to increase the resistance of hard alloys, refractory carbides, such as tantalum carbide, are introduced into their composition, which significantly increases the resistance to deformation at high temperatures. However, the exact mechanism of the positive effect of tantalum carbide on the properties of hard alloys requires further research,” said Evgeny Levashov, Doctor of Engineering Sciences, Head of the Department of Powder Metallurgy and Functional Coatings at NUST MISIS.
Scientists from MISIS University studied the mechanical properties and structural changes of hard alloys with tantalum carbide additives using a unique technique with simultaneous heating and video recording of structural changes in electron-transparent objects made of hard alloys directly in the column of a transmission electron microscope. The technique also made it possible to conduct micromechanical tests of materials, including at elevated temperatures. The details of the study are described in the scientific journal “News of Universities. Powder Metallurgy and Functional Coatings”.
“We have shown that the resistance to deformation at elevated temperatures in a tungsten-based hard alloy (WC-6% Co) alloyed with tantalum carbide is associated with the formation of strengthening tantalum-containing nanoparticles in the metal matrix of the composite,” said PhD Alexander Zaitsev, senior researcher at the laboratory “In situ Diagnostics of Structural Transformations” of the Scientific and Educational Center for Self-Propagating High-Temperature Synthesis MISIS-ISMAN.
The results of the study made it possible to open up new prospects in the alloying strategy when improving the technology for the production of hard alloys. Expanding the fundamental understanding of the deformation mechanism at elevated temperatures made it possible to obtain a tool for coal mining with a twofold increase in service life.