Premium
Hot Isostatic Pressing of Si 3 N 4 Powder Compacts and Reaction‐Bonded Si 3 N 4
Author(s) -
Heinrich Juergen,
Backer Eberhard,
Böhmer Manfred
Publication year - 1988
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.1151-2916.1988.tb05774.x
Subject(s) - materials science , hot isostatic pressing , microstructure , silicon nitride , sintering , creep , grain boundary , scanning electron microscope , metallurgy , phase (matter) , yttria stabilized zirconia , hot pressing , grain size , powder metallurgy , nitride , silicon , composite material , ceramic , cubic zirconia , chemistry , organic chemistry , layer (electronics)
Hot isostatically pressed silicon nitride was produced by densifying Si 3 N 4 powder compacts and reaction‐bonded Si 3 N 4 (RBSN) parts with yttria as a sintering additive. The microstructure was analyzed using scanning electron microscopy, X‐ray diffraction, and density measurements. The influence of the microstructure on fracture strength, creep, and oxidation behavior was investigated. It is assumed that the higher amount of oxygen in the Si 3 N 4 starting powder compared with the RBSN starting material leads to an increased amount of liquid phase during densification. This results in grain growth and in a larger amount of grain boundary phase in the hot isostatically pressed material. Compared with the hot isostatically pressed RBSN samples therefore, strength decreases whereas the creep rate and the weight gain during oxidation increase.