Metalurgija, Vol. 58 No. 1-2, 2019.
Izvorni znanstveni članak
Preparation and properties of SiAlON ceramics by gel casting and pressureless sintering
J. Li
orcid.org/0000-0002-6099-8349
; School of Metallurgy and Environment, Central South University, Changsha, China
C. F. Zhang
; School of Metallurgy and Environment, Central South University, Changsha, China
R. M. Yin
; College of Metallurgical Engineering, Hunan University of Technology, Zhuzhou, China
W. H. Zhang
; School of Metallurgy and Environment, Central South University, Changsha, China
Sažetak
This study employed a low-toxicity N, N-dimethylacrylamide/N, N-methylene acrylamide (DMAA /MBAM) gel system to near net shape SiAlON ceramics from aqueous slurries with a solid loading of 40 wt.% Si3N4, Al2O3, Y2O3, AlN, and Ce2O3 powder mixtures. The green bodies were sintered by one- and three-step pressureless sintering. Results showed that green bodies had a homogeneous microstructure with a high density of 1,9 g/cm3 and high flexural strength of 28,6 Mpa. Equiaxed α-SiAlON was prepared by one-step pressureless sintering, whereas β-Si4Al2O2N6 with an elongated morphology was fabricated by three-step pressureless sintering. Therefore, a lowtemperature heat preservation stage reduces the nucleation rate, which is favorable for the development of elongated β-SiAlON grains.
Ključne riječi
SiAlON ceramics; gelcasting; pressureless sintering; microstructure; mechanical properties
Hrčak ID:
206499
URI
Datum izdavanja:
1.1.2019.
Posjeta: 1.128 *