| Summary: | 碩士 === 逢甲大學 === 紡織工程研究所 === 81 === 2-D carbon / carbon composites were prepared with phenol -
formaldehyde resin , one kind of commercial stabitized PAN
fabric and its carbonized fabrics, which well carbonized and
graphitized in our laboratory. The effect of carbonization and
and graphitization on the microstructure, fracture behavior and
and flexural strength of the composites during the pyrolysis
were studied. In this study, the stabilized PAN fabrics were
carbonized and graphitized to 400■、600■、800■、1000■
、1300■ 、2000■、and 2500■，respectively . The composites
were made from a phenolic resin matrix with these fabrics,
respectively. The void content of the composites played an
important role on void content and cracks of the composites,
when the composites were carbonized up to 600■ ,the void
content increased remarkable . During carbonization, the
shrinkages of the matrix were inhibited due to existence of the
chemical bonding between the fibers and the matrix.Because of
the strong interface in the fibers and the matrix, the weight
loss of composites were less than that of the fibers and the
matrix. During graphitization, interlayer spacing and the
stacking size also increased with the increase in the
graphitization temperature. The composites with the fabrics
heat treated at a lower temperature showed a brittle fracture
pattern, whereas those heat treated at a higher temperature
showed a pseudo-plastic fracture with fiber pull - out. The
former carbon/ carbon composites failed in mixed tensile cum
shear mode and showed lower strength, owing to formation voids
and cracks during carbonization. The latter composites
exhibited continuous fracture and showed higher toughness.
During graphitization are also.
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