QUALITY CONTROL OF THE STRUCTURE AND PROPERTIES OF WC-Co CERMETS OBTAINED BY SINTERING IN A HYDROGEN ATMOSPHERE

The article is dedicated studying the structural and physico-chemical properties of cermets based on tungsten carbide with 6% α-Co (WC&6% α-Co) in order to ensure the quality of a material. The X-ray diffraction pattern of the sample showed that together with the characteristic peaks of WC there is a peak of the (111) α-Co phase. The phase composition of the sintered material has not changed. To evaluate the quality of WC&6% α-Co cermets, their elastic properties were studied by measuring phase velocities of longitudinal and shear bulk acoustic waves (BAW). These measurements have been obtained using the long pulse method in the range of 10 – 70 MHz for longitudinal waves and in the vicinity of 10 MHz for shear waves. The density of the sample has been measured using a pycnometric method. Based on the obtained data in the isotropic approximation for WC&6% α-Co ceramics, the elastic moduli C11, C12, C44, as well as Young’s modulus, shear modulus, bulk modulus of elasticity and Poisson’s ratio were calculated. The results were compared with data presented in the literature. It has been demonstrated that the elastic constant values of WC&6% α-Co ceramics can vary by up to 20% in different studies. First of all the reasons for such discrepancies are related to differences in the features of the technological process for a ceramics manufacturing. The use of ceramics of this composition is promising when creating parts for high-pressure chambers for research purposes, for technological equipment, in particular for the method of hot pressing of hard and superhard materials and also as substrates in double-layer diamond - WC plates. The high-frequency acoustic method for studying the elastic properties of tungsten carbide can be successfully used to diagnose the quality of such materials. Ways to improve the technological process for producing cermets based on tungsten carbide have been identified. For citation: Sorokin B.P., Yashin D.V., Prokhorov V.M., Aksenenkov V.V. Quality control of the structure and properties of WC-Co cermets obtained by sintering in a hydrogen atmosphere. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 10. P. 29-37. DOI: 10.6060/ivkkt.20246710. 8y.