INFLUENCE OF COMPOSITION AND PRESSURE ON MECHANICAL PROPERTIES AND WEAR RESISTANCE OF CIALON
Abstract
The kinetics of sintering under pressure of 10 and 25 MPa β′-sialons with composition Z = 1.0; 2.0, obtained from powders of silicon nitride with 5% α-phase, 95% β-phase and 79% α-phase, 21% β-phase. It was found that in materials using Si3N4 powder with a high content of α-phase at a pressure of 10 MPa, the seal passes to a relative density of 0.96 - 0.98, and the amount of liquid phase has little effect on the compaction rate. The porosity, crack resistance, hardness and wear resistance of β′-sialons with composition Z = 1.0 were studied; 2.0, obtained from powders of silicon nitride at a pressure of 25 and 10 MPa. It was found that when using silicon nitride powder with a high content of α-phase, the porosity of the materials is 30-50% lower than when using a powder with a low content. This reduction does not depend on the sintering pressure, and crack resistance, hardness, wear resistance of materials increase by 10-30%. The dependences of crack resistance, hardness and wear resistance of β′-sialons on their composition in the range of Z = 1-3, as well as exposure time during sintering at a pressure of 10 MPa were studied. The process of obtaining products from sialon by hot pressing at a pressure of 10 MPa, which provides wear resistance of the material at the level of wear resistance of sialon sintered at a pressure of 25 MPa. `
