抄録
The starting materials used in this study were single-walled carbon nanotubes (SWCNTs) synthesized by an arc discharge method and multi-walled carbon nanotubes (MWCNTs) prepared by a CVD method (NanoLab, Inc.). A spark plasma sintering (SPS) method was utilized to solidify SWCNTs and MWCNTs. To facilitate the solidification, phenol resin (50 mass%) was added to the purified SWCNTs and MWCNTs. The compaction pressures used in the SPS method were 40 MPa for SWCNTs and 80 MPa for MWCNTs, and the temperature was 1000°C. The mechanical properties of the solidified SWCNTs and MWCNTs were examined using a small punch (SP) testing method. The SWCNT solids showed significant non-linear deformation response, producing quasi-ductile fracture behavior, and Young's modulus and work of fracture were 1.6 GPa and 15.8 N · mm, respectively. In contrast, the MWCNT solids showed brittle fracture behavior, and Young's modulus and work of fracture were 1.5 GPa and 4.4 N · mm, respectively. TEM observations revealed that the fracture of the SWCNT solids was characterized by pull out of SWCNT bundles, and that of the MWCNT solids was characterized by “bamboo-like” failure of MWCNTs.
