Lower-Temperature Hot-Pressed Dy-α-Sialon Ceramics with an LiF Additive

Hot-pressed Dy-α-sialon ceramics, using LiF as a sintering additive, were fabricated at lower temperatures (≤1650°C). Some of the densified samples possessed higher hardness and fracture toughness up to 19.00–20.00 GPa and 4.00–6.00 MPa·m^1/2, respectively. The amount of LiF had a strong effect on the densification behavior in sialon preparation. As one of the experimental results, the sample with 0.1 wt% of LiF additive sintered at 1600°C produced an optical translucence of about 50% in the range of 1.5–5.0 μm wavelengths. The maximum infrared transmission reached ∼60% at a wavelength of 2.4 μm. It is inferred that these more easily sintered materials would be practical for optical applications in certain fields.