Effects of PyC coating on SiC fibers after ultra-high temperature annealing

Effects of pyrocarbon interphase on microstructure and properties of C/SiBCN composites

“…The PyC interphase was deposited onto the fiber preform via CVD using C 3 H 6 at 960 °C for 5 h, 15 h, and 30 h. Detailed information about this deposition can be found elsewhere [13]. The fiber preforms became more rigid and difficult to compress as the PyC content increased, making it unable to maintain the volume fraction of fibers in the preform at 44.4%.…”

“…The thicknesses of the PyC coating on the fibers after deposition times of 5 h, 15 h, and 30 h were ∼100 nm, ∼250 nm, and ∼500 nm, respectively (figure 1). The PyC interphases had rough surfaces that were strongly bonded with carbon fiber, which is conducive to improving the interface bonding strength between fiber and matrix [13,14]. After deposition for 5 h, carbon fibers were covered with a rough PyC coating with a thickness of 100 nm (figures 1(a), (b)); this rough surface is advantageous for increasing the frictional sliding resistance of pullout fibers in C/SiBCN composites [13].…”

“…The PyC interphases had rough surfaces that were strongly bonded with carbon fiber, which is conducive to improving the interface bonding strength between fiber and matrix [13,14]. After deposition for 5 h, carbon fibers were covered with a rough PyC coating with a thickness of 100 nm (figures 1(a), (b)); this rough surface is advantageous for increasing the frictional sliding resistance of pullout fibers in C/SiBCN composites [13]. As the deposition time increased to 15 h, the thickness of the PyC coating increased to ∼250 nm (figures 1(c), (d)).…”

“…Investigations of improvements in the properties of C/SiBCN composites after high-temperature treatment should focus on the interphase between carbon fibers and the matrix, because this interphase has a greatly influence on the properties of the composites [10]. Carbon fibers are typically coated with C [13,14], SiC [8,15], BN [16,17], etc as the interphase. The most common coating for optimizing the interphase are pyrocarbon (PyC).…”

Fabrication and properties of SiCnw‐reinforced SiC composites by reactive melt infiltration with BN and PyC interface

“…[20][21][22][23] In order to meet the previous requirements, the interface materials for CMC are considered should have a layered structure, 24 for example, PyC and h-BN. Zhang et al 25 studied the mechanical properties of SiC fibers with and without PyC interfaces under different annealing conditions and the results showed that the tensile strength retention of SiC fibers with PyC interfaces was 15.9% higher than that without interfaces. Ding et al 26 employed dip-coating to synthesize BN coating and combined with CVI to prepare SiC CMC.…”