TY - GEN
T1 - Microcracking and mechanical properties of YBa2Cu3Ox ceramics
AU - Severin, J.W.
AU - With, de, G.
PY - 1988
Y1 - 1988
N2 - Elasticity, hardness and fracture data have been measured on superconducting
YBa, Cu3 O~ ceramics with a relative density ranging from 87 to 93% and a grain size
from about 10 to 2411m. For the 93% dense material a value of 112 GPafor the Young’s
modulus and a hardness value of about 4.5 GPa are obtained. The strength andfracture
toughness are dependent on cooling rate. A strength of 86 and 117 MPa are obtained
for ‘fast’ and ‘slow’ cooling rates respectively. The corresponding fracture toughness
measurements yielded 1•2 and 1•4 MPa. m1. The fracture toughness can be sign~cantly
lower, as observed on some specimens, probably by reaction with water at the grain
boundaries. Extensive microcracking, in agreement with theoretical expectations, was
observed by microscopy. Further evidence from mercury intrusion porosimetry and N,
adsorption analysis is presented. Possible consequences are discussed.
AB - Elasticity, hardness and fracture data have been measured on superconducting
YBa, Cu3 O~ ceramics with a relative density ranging from 87 to 93% and a grain size
from about 10 to 2411m. For the 93% dense material a value of 112 GPafor the Young’s
modulus and a hardness value of about 4.5 GPa are obtained. The strength andfracture
toughness are dependent on cooling rate. A strength of 86 and 117 MPa are obtained
for ‘fast’ and ‘slow’ cooling rates respectively. The corresponding fracture toughness
measurements yielded 1•2 and 1•4 MPa. m1. The fracture toughness can be sign~cantly
lower, as observed on some specimens, probably by reaction with water at the grain
boundaries. Extensive microcracking, in agreement with theoretical expectations, was
observed by microscopy. Further evidence from mercury intrusion porosimetry and N,
adsorption analysis is presented. Possible consequences are discussed.
M3 - Conference contribution
T3 - British Ceramic Proceedings
SP - 249
EP - 256
BT - Superconducting ceramics
A2 - Freer, R.
PB - The Institute of Ceramics
CY - Stoke-on-Trent
ER -