Coal tar mesophase pitch fibres stabilized at 270° C to different extents were carbonized under strain by the constant load or constant length, using different heating rates, and further graphitized at 2500° C. Shallow and moderate stabilization provided a skin-core structure in the resultant fibres which exhibited higher orientation, tensile modulus, and better graphitizability after calcination at 1300° C and graphitization at 2500° C than deep stabilization. The tensile strength and modulus of the graphitized fibre was significantly improved through the strained carbonization when the stabilization was performed to a moderate extent. The strain tended to give an onion-like alignment in the fibre to improve the preferred orientation of carbon planes. Larger load and more rapid heating during carbonization modified the structure and properties of resultant fibres through a significant longitudinal elongation. The stabilization extent of pitch fibres governs the mobility or fusibility of mesogen molecules at the carbonization which allows their better alignment by the strain.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering