Abstract
With a high temperature test set-up the fracture toughness (K{sub Ic}) of Wesgo Al-995 alumina, NKA A16SG.cip alumina, SiC and ferrite was determined with chevron notched bars loaded in four point bending at room temperature. The two aluminas were also tested at 600{sup o}C and 1000{sup o}C and the ferrite at 400{sup o}C. K{sub Ic} was determined from maximum load which was obtained from load versus displacement curves recorded during the tests. The test results are consistent with the results obtained previously with a room temperature set-up. With the Griffith relation for half circular surface cracks, the decrease in fracture toughness of the aluminas was compared with the decrease in Weibull strength for a unit surface obtained from three and four point bending tests. This reveals that the decrease in bending strength with temperature can only partly be explained by the reduction in fracture toughness. The results indicate that compressive residual stresses are present in the Wesgo alumina and probably also in the NKA alumina bending bars. For the NKA alumina the comparison is probably not valid due to a change in defect population at 1000{sup o}C. 8 figs., 5 tabs., 7 refs.
Citation Formats
De Smet, B J, and Bach, P W.
High temperature fracture toughness of alumina, ferrite and silicon carbide.
Netherlands: N. p.,
1992.
Web.
De Smet, B J, & Bach, P W.
High temperature fracture toughness of alumina, ferrite and silicon carbide.
Netherlands.
De Smet, B J, and Bach, P W.
1992.
"High temperature fracture toughness of alumina, ferrite and silicon carbide."
Netherlands.
@misc{etde_10127282,
title = {High temperature fracture toughness of alumina, ferrite and silicon carbide}
author = {De Smet, B J, and Bach, P W}
abstractNote = {With a high temperature test set-up the fracture toughness (K{sub Ic}) of Wesgo Al-995 alumina, NKA A16SG.cip alumina, SiC and ferrite was determined with chevron notched bars loaded in four point bending at room temperature. The two aluminas were also tested at 600{sup o}C and 1000{sup o}C and the ferrite at 400{sup o}C. K{sub Ic} was determined from maximum load which was obtained from load versus displacement curves recorded during the tests. The test results are consistent with the results obtained previously with a room temperature set-up. With the Griffith relation for half circular surface cracks, the decrease in fracture toughness of the aluminas was compared with the decrease in Weibull strength for a unit surface obtained from three and four point bending tests. This reveals that the decrease in bending strength with temperature can only partly be explained by the reduction in fracture toughness. The results indicate that compressive residual stresses are present in the Wesgo alumina and probably also in the NKA alumina bending bars. For the NKA alumina the comparison is probably not valid due to a change in defect population at 1000{sup o}C. 8 figs., 5 tabs., 7 refs.}
place = {Netherlands}
year = {1992}
month = {Dec}
}
title = {High temperature fracture toughness of alumina, ferrite and silicon carbide}
author = {De Smet, B J, and Bach, P W}
abstractNote = {With a high temperature test set-up the fracture toughness (K{sub Ic}) of Wesgo Al-995 alumina, NKA A16SG.cip alumina, SiC and ferrite was determined with chevron notched bars loaded in four point bending at room temperature. The two aluminas were also tested at 600{sup o}C and 1000{sup o}C and the ferrite at 400{sup o}C. K{sub Ic} was determined from maximum load which was obtained from load versus displacement curves recorded during the tests. The test results are consistent with the results obtained previously with a room temperature set-up. With the Griffith relation for half circular surface cracks, the decrease in fracture toughness of the aluminas was compared with the decrease in Weibull strength for a unit surface obtained from three and four point bending tests. This reveals that the decrease in bending strength with temperature can only partly be explained by the reduction in fracture toughness. The results indicate that compressive residual stresses are present in the Wesgo alumina and probably also in the NKA alumina bending bars. For the NKA alumina the comparison is probably not valid due to a change in defect population at 1000{sup o}C. 8 figs., 5 tabs., 7 refs.}
place = {Netherlands}
year = {1992}
month = {Dec}
}