Premium
Effect of the Sintering Additive on Microstructure and Mechanical Properties of Hi ‐Nicalon TM SiC Fibers in a HfB 2 Matrix
Author(s) -
Silvestroni Laura,
Guicciardi Stefano,
Nygren Mats,
Melandri Cesare,
Sciti Diletta
Publication year - 2013
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/jace.12018
Subject(s) - microstructure , materials science , spark plasma sintering , nanoindentation , composite material , sintering , flexural strength , scanning electron microscope , fracture toughness , fiber , toughness , transmission electron microscopy , modulus , nanotechnology
This study is focused on the effect of the sintering additive on the microstructure and properties of HfB 2 composites reinforced with SiC Hi –Nicalon fibers. The materials were spark plasma sintered with addition of 5–10 vol% of Si 3 N 4 or ZrSi 2 . The fibers morphology was examined using scanning and transmission electron microscopy and remarkable differences were observed depending on the additive. Local hardness and Young's modulus were measured by nanoindentation to investigate the fiber mechanical behavior. The introduction of 20 vol% SiC short fibers into the HfB 2 matrix increased the fracture toughness up to 5.4 MPa m 1/2 for the material sintered with ZrSi 2 . The room temperature flexural strength of the materials containing fibers slightly decreased when ZrSi 2 was used, but with the addition of Si 3 N 4 an improvement of more than the 40%, as compared to the unreinforced material was observed.