Creep of SiC–SiC microcomposites

Tensile creep and rupture of 2D-woven SiC/SiC composites for high temperature applications

“…This implies that after 100 h the matrix is still carrying part of the composite load. Thus a more complicated analysis is required for prediction of MI composite strain rate after 100 h at 1315 • C. [31][32][33] Interestingly, the strain rates for the 138 MPa HNS composites with fiber-bridged matrix cracks were near the fiber data from Sauder and Lamon.…”

“…10a. Strain rates from literature data for CVI SiC measured at 1300 • C by Rugg et al 33 and a bulk siliconized SiC (37% Si) tested in tension by Wiederhorn et al 39 are shown on Fig. 10a for comparison.…”

“…It should be noted that the CVI SiC data appears to not have reached a steady state and minimum strain rate data was used from the two CVI SiC matrix creep curves of Ref. 33. It can be seen that the data for the CVI SiC and siliconized SiC are very similar in creep, which may be why the iBN CVI and iBN MI composite data are so similar in strain rate when normalized by fiber fraction.…”

Time-dependent deformation in an enhanced SiC/SiC composite

“…[1] through [3] are combined, the following expression can be obtained: [4] where k is a constant. [12,26,27] By comparing the time exponent (q), stress exponent (n), and creep activation energy of the composite to those of the fiber, it is considered that creep of the composite is probably controlled by creep of the fibers. [12,26,27] By comparing the time exponent (q), stress exponent (n), and creep activation energy of the composite to those of the fiber, it is considered that creep of the composite is probably controlled by creep of the fibers.…”

Creep properties of melt infiltrated SiC/SiC composites with Sylramic™‐iBN and Hi‐Nicalon™‐S fibers

“…Another observation is that the apparent minimum creep rate at a fixed temperature and stress in both composites decreases with increase in exposure time without reaching a minimum creep rate even until final failure similarly to chemical vapor deposited SiC monofilaments and CVI SiC/SiC composites. [44][45][46] This indicates that in these composites creep behavior is essentially primary creep and secondary creep does not even exist. There are two reasons for this type of behavior.…”