Powders (Oct 2023)

Effect of Induction Heating on Surface Properties of Hot-Pressed Ceramics Based on Nanopowders Si<sub>3</sub>N<sub>4</sub> and TiN

  • Lina L. Sartinska

DOI
https://doi.org/10.3390/powders2040043
Journal volume & issue
Vol. 2, no. 4
pp. 697 – 708

Abstract

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The effect of induction heating on the surface properties of hot-pressed ceramics based on plasma chemical nanopowders Si3N4 and TiN (additives: Al2O3, AlN, and Y2O3) has been studied. The research demonstrates the formation of a modified layer on the surface of the hot-pressed material. The study examines the porosity, hardness, fracture toughness, brittleness, distribution of elements, and wear of hot-pressed ceramics on the surface before and after additional grinding. Removal of the surface porous layer results in increased density and hardness, leading to a higher number of acoustic emission signals during scratching with a Vickers indenter. A different response to scratching indicates a transgranular or intergranular fracture of the structure. The presence of porosity and carbon contamination on the surface layer of materials negatively impacts the properties of TiN-reinforced ceramics based on Si3N4-Al2O3-AlN (SIALON). However, the addition of Y2O3 effectively prevents carbon penetration and reduces the effect of grinding. Additionally, the dark-colored tone observed on the outer volume of the samples suggests a non-thermal microwave effect of the induction furnace.

Keywords