Abstract
The paper presents the assessment results of the influence of ionic modification of the near-surface layers of composite ceramics based on titanates on changes in resistance to external mechanical influences. The method of irradiation with O + ions with an energy of about 28 MeV was chosen as the main method for modification of composite ceramics; irradiation fluences were selected in the range from 10 11 to 10 14 ion/cm 2 . According to the data obtained, a change in the ratio of components during mixing leads to the formation of two-phase ceramics, in which the main phase is ZnTiO 3 , and impurities in the form of ZnO and TiO 2 are also present, depending on the weight contributions of the initial components. It was determined that the phase composition alteration associated with an increase in the ZnTiO 3 phase in the composition results in hardness and cracking resistance growth, which is due to a combination of changes in phase composition and size effects. During experiments related to the ion modification of the studied xZnO - (1-x)TiO 2 ceramics, it was established that at irradiation fluences of 10 11 –5·10 12 ion/cm 2 , the formation of a strengthening effect of the near-surface layer, caused by the effect of ions on the crystal structure, and the associated effects of dislocation strengthening, is observed. At fluences above 5·10 12 ion/cm 2 , a decrease in the degree of strengthening of ceramics, associated with an increase in the density of structural defects, their agglomeration and subsequent destabilization of the near-surface layer, which reduces resistance to external influences, including mechanical pressure, leading to crack formation, is observed.