Premium
Mechanical Properties of Polycrystalline β‐Sic
Author(s) -
GULDEN T. D.
Publication year - 1969
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.1151-2916.1969.tb15845.x
Subject(s) - materials science , transgranular fracture , crystallite , composite material , grain boundary , intergranular corrosion , flexural strength , cleavage (geology) , fracture (geology) , intergranular fracture , grain size , stress (linguistics) , microstructure , metallurgy , linguistics , philosophy
The mechanical properties of chemically vapor‐deposited β‐Sic were measured in bending between room temperature and 1400°C. Material with grain diameters from less than 1 to 15 μm was tested. No grain‐size dependence of the bend strength of dense (<99% of theoretical) Sic was observed at any test temperature. The fracture strength of dense Sic remained approximately constant between room temperature and about 900°C and then increased sharply up to the maximum test temperature of 1215° to 1400°C. This increase in fracture stress coincided with the onset of plastic yielding detectable in the stress‐strain curves. The fracture mode of this material was transgranular cleavage at all test temperatures. The fracture stress of Sic of lower density, which was characterized by the presence of grain boundary flaws, decreased slightly at high temperature. The fracture mode of the low‐density (3.17 g/cm 3 ) β‐Sic underwent a transition from predominantly transgranular at room temperature to predominantly intergranular at high temperature.