Open AccessPressureless sinterability study of ZrB2–SiC composites containing hexagonal BN and phenolic resin additives
Author(s) -
Iman Farahbakhsh,
Riccarda Antiochia,
Ho Won Jang
Publication year - 2021
Publication title -
synthesis and sintering
Language(s) - English
Resource type - Journals
eISSN - 2564-0194
pISSN - 2564-0186
DOI - 10.53063/synsint.2021.1231
Subject(s) - materials science , sintering , composite material , scanning electron microscope , delamination (geology) , yield (engineering) , impurity , hexagonal crystal system , ceramic , hot pressing , oxide , energy dispersive x ray spectroscopy , carbon fibers , metallurgy , crystallography , chemistry , composite number , paleontology , organic chemistry , biology , subduction , tectonics
This research is dedicated to the role of different amounts of hexagonal BN (hBN: 0, 1.5, 3, and 4.5 wt%) on the pressureless sinterability of ZrB2–25 vol% SiC ceramics. Phenolic resin (5 wt%) with a carbon yield of ~40 % was incorporated as a binder to the powder mixtures and after initial cold pressing, the final sintering process was performed at 1900 °C for 100 min in a vacuum furnace. The as-sintered specimens were characterized by X-ray diffractometry, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The results disclosed that the incorporation of 1.5 wt% hBN could increase the relative density to ~92%, while the sample with zero hBN content just reached ~81% of full densification. Appropriate hBN content not only facilitated the particle rearrangement during the cold pressing, but also removed the harmful oxide impurities during the final sintering. Nevertheless, the addition of higher amounts of hBN remarkably lessened the densification because of more delamination of the non-reacted hBN flakes and release and entrapment of more gaseous by-products induced by the reacted hBN phases.