Mechanical properties of simultaneously synthesized and consolidated carbon nanofiber (CNF)-dispersed SiC composites by pulsed electric-current pressure sintering

作者：Hirota Ken^*; Hara Hiroaki; Kato Masaki

来源：Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 2007, 458(1-2): 216-225.

DOI：10.1016/j.msea.2006.12.065

• silicon carbides (SiC)
• carbon nanofiber (CNF)
• simultaneous synthesis and consolidation
• pulsed electric-current pressure sintering
• mechanical properties
• high-temperature strength

Carbon nanofiber (CNF) dispersed beta-SiC composites with the addition of 0.2 mass% boron and 2.0 mass% carbon as sintering aids have been synthesized and consolidated simultaneously from mixtures of Si, amorphous C and B powders and CNF by pulsed electric-current pressure sintering (PECPS). Synthesis and consolidation process, which were observed from their expansion and shrinkage curves during PECPS, have been examined using X-ray diffraction and scanning electron microscopy for the powder compacts. CNF/SiC composites sintered at 1800 degrees C for 10 min under 40 MPa in a vacuum have similar to 96.0% of theoretical density and homogeneous structures consisting of similar to 4.0 mu m grains. A 10 vol% CNF/SiC composite exhibited excellent mechanical properties: a bending strength of similar to 720 MPa, a Vickers hardness of similar to 26.0 GPa, and a fracture toughness of similar to 5.5 MPa m(1/2). High-temperature bending strength of similar to 890 MPa at 1200 degrees C in air was attained with the same nanocomposites.

• 出版日期2007-6-15