Interlaboratory round robin study on axial tensile properties of SiC‐SiC CMC tubular test specimens

Abstract

An interlaboratory round robin study was conducted on the tensile strength of SiC‐SiC ceramic matrix composite (CMC) tubular test specimens at room temperature with the objective of expanding the database of mechanical properties of nuclear grade SiC‐SiC and establishing the precision and bias statement for standard test method ASTM C1773. The mechanical properties statistics from the round robin study and the precision statistics and precision statement are presented herein. The data show reasonable consistency across the laboratories, indicating that the current C1773‐13 ASTM standard is adequate for testing ceramic fiber reinforced ceramic matrix composite tubular test specimen. It was found that the distribution of ultimate tensile strength data was best described with a two‐parameter Weibull distribution, while a lognormal distribution provided a good description of the distribution of proportional limit stress data.

Analysis of SiC/SiC composites for energy applications at ambient conditions

“…Proportional limit values, or the deviation from linearity (DFL), were calculated from a 0.005% strain offset. Generally, published properties of CMCs vary greatly as they depend on many factors, including fiber type, interphase thickness, tow architecture, loading mode, etc 12,22‐24 . Mechanical properties of the CMCs evaluated here fall within typical ranges; these expected ranges were derived from mechanical testing of similarly structured CMCs in tension and bending, respectively.…”

“…Generally, published properties of CMCs vary greatly as they depend on many factors, including fiber type, interphase thickness, tow architecture, loading mode, etc. 12,[22][23][24] Mechanical properties of the CMCs evaluated here fall within typical ranges; these expected ranges were derived from mechanical testing of similarly structured CMCs in tension and (1) bending, respectively. Some deviation from these ranges may be expected due to the specific fiber architecture used in this testing, but the general agreement between results of this testing and those presented in literature supports a high degree of confidence in the results despite the use of only two samples per loading mode.…”

Unveiling hermetic failure of ceramic tubes by digital image correlation and acoustic emission

“…Two more sequential jumps in He leak rate ( Figure 8D,E) were T A B L E 4 Summary of CMC experimental properties and literature properties. 5,14,38,39 caused by additional crack opening before final loss of load-bearing capacity of CMC_03. The elastic response of each CMC specimen aligned well ( Figure 9A), but the continued response beyond the DFLS highlighted the differences between the specimens.…”

Impact of Control Blade Insertion on the Deformation Behavior of SiC-SiC Channel Boxes in Boiling Water Reactors

“…The channel box reaches a maximum stress of 155 MPa. This maximum stress is lower than the ultimate tensile strength (~250 MPa) of SiC-SiC composites, but greater than the proportional limit stress (~90 MPa) [31]. Thus, matrix microcracking is expected but a fully developed, through wall crack may not occur.…”

“…Figure 17 shows the maximum principal stress distribution in the channel box, and shows that a maximum stress of 125 MPa will develop in the channel box after about 141 days. Since the stress is greater than the proportional limit stress of the material (~90 MPa [31]), matrix microcracking is likely to occur.…”