ОСОБЛИВОСТІ МІКРОСТРУКТУРИ КОМПОЗИТІВ WC‒Co, ЗМІЦНЕНИХ ДОБАВКОЮ CrB2

• Date: 2022
• Main Authors: Ратов, Б. Т., Бондаренко, М. О., Мечник, В. О., Стрельчук, В. В., Колодніцький, В. М., Ніколенко, А. С., Коростишевський, Д. Л., Пошванюк, Н. Ф.
• Format: Article
• Language: Ukrainian
• Published: Институт сверхтвердых материалов им. В. Н. Бакуля Национальной академии наук Украины 2022
• Subjects: композит; карбід вольфраму; кобальт; диборид хрому; склад; концентрація; вакуумне гаряче пресування; структура; властивості
• Online Access: http://altis-ism.org.ua/index.php/ALTIS/article/view/251
• Journal Title: Tooling materials science

Samples of composites 10 mm in diameter and 8 mm thick based on tungsten carbide and cobalt with different (from 0 to 10%) chromium diboride content were formed by cold pressing methods followed by vacuum hot pressing. A comprehensive study of composites using traditional methods of testing mechanical properties in combination with methods of digital optical and scanning microscopy made it possible to establish stable correlations between the content of the CrB2 additive with the average grain size of WC, microstructure parameters, bending strength, and ultimate compressive strength. It is shown that for the composites WC–6% Co (%wt), a coarse-grained structure is observed both with direct contact of WC grains and with large areas of cobalt binder. The doping of CrB2 additive in the composition of the composite, on the contrary, makes it possible to form finer-grained structures, the parameters of which can be purposefully controlled by changing its concentration. The optimal content of CrB2 in the WC–6Co composite from the point of view of the complex of physical and mechanical properties has been established. The addition of 4% chromium diboride in the composition of the WC–6Co composite causes a significant increase in the ultimate bending strength (from 2000 to 2500 MPa) and ultimate compressive strength (from 5300 to 5500 MPa).