Optical and mechanical properties of transparent alumina fabricated by high-pressure spark plasma sintering. Issue 8 (July 2019)

• Record Type: Journal Article
• Authors: Ratzker, Barak; Wagner, Avital; Sokol, Maxim; Kalabukhov, Sergey; Dariel, Moshe P.; Frage, Nachum
• Is Part Of: Journal of the European Ceramic Society. Volume 39:Issue 8(2019)
• Page Start: 2712
• Page End: 2719
• Publication Date: 2019-07
• Subjects: Alumina -- High-pressure spark plasma sintering -- Transparent -- Hardness; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2019.03.025
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: Transparent alumina was fabricated from untreated commercial powder by high-pressure spark plasma sintering (HPSPS) at temperatures of 1000, 1050 and 1100 °C under pressures of 250-800 MPa. It was established that transparency strongly depends on the HPSPS parameters. At all temperatures, there was a certain point when increasing the pressure led to decreasing transparency. At 1100 °C, relatively high pressure led to excessive grain growth, as well as the formation of creep-induced porosity at the center of the samples. Hardness values decreased with pressure due to grain growth, correlated with the Hall-Petch relationship. The optimal combination of optical and mechanical properties (68% in-line transmittance at a wavelength of 640 nm and a hardness value of about 2300 HV2) was achieved after sintering at 1050 °C under 600 MPa.