Premium
Microstructure, Strength, and Oxidation of a 10 wt% Zyttrite‐Si 3 N 4 Ceramic
Author(s) -
DUTTA SUNIL,
BUZEK BRUNO
Publication year - 1984
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1984.tb09621.x
Subject(s) - microstructure , materials science , equiaxed crystals , ceramic , porosity , composite material , metallurgy , flexural strength
Hot‐pressed Si 3 N 4 doped with 10 wt% zvttrite as a sinterine aid was studied. An equiaxed, fine‐grainid microstructure was predominant, with no apparent porosity. Bend strengths were determined at room temperature and high temperatures (up to 1370°C/2500°F). Oxidation was measured by weight gain at 1370°C in air. The resulting material exhibited very good room‐temperature strength (755 MPa/110 ksi). The work showed that room‐temperature strength can be improved significantly by using controlled Si 3 N 4 powder with 10 wt% zyttrite. High‐temperature strength (514 MPd75 ksi) at 1370°C was nearly double that of hot‐pressed Si 3 N 4 (NC‐132). The oxidation resistance at 1370°C was also higher than that of NC‐132.