Masaomi Horita

Mechanical and Electrical Properties of Carbon Nanofiber Dispersed Ti Composite Formed by Compression Shearing Method at Room Temperature

The materials used for fuel cell separators require a bending strength of more than 70 MPa. Therefore, the contact resistance is required to be 10 mΩ∙cm2, respectively. In the present study, vapor grown carbon nanofibers (VGCF) were added to Ti composite using the compression shearing method at room temperature. The mechanical properties of the compacted powder were then measured. The microstructure of the Ti/VGCF composite material was Ti with dispersed VGCF (not alloyed). In addition, the bending strength of all Ti/VGCF composites was more than 800 MPa, and the bending strength of 0-1 vol% VGCF composites was twice as much as that for Ti rolled material (ASTM grade 2). Ti/VGCF thin plates also exhibited excellent electrical property. The contact resistance of 5 vol% VGCF was found to be three times smaller than that of Ti rolled material. These properties make the Ti/VGCF composite material suitable as a separator material.

Fabrication of WS2-Dispersed Al Composite Material by Compression Shearing Method at Room Temperature

In this study, WS2-dispersed Al composite material was fabricated by Compression Shearing Method at Room Temperature, using various WS2 content ratios. The mechanical and friction properties of the WS2-dispersed Al composites were measured. As a result, the density measurements showed that the compacted WS2-dispersed aluminum composite had a relative density of 95 to 99%. Tensile strength of WS2-dispersed Al has 200 MPa. The friction coefficient of Al/0.5vol.%WS2 was 0.14, a reduction of 83%, in comparison with the 1.0 friction coefficient of the pure Al matrix material. The addition of WS2 to the matrix systems used reduced the friction coefficient. Therefore, WS2-dispersed Al composite material is useful for maintenance-free material of slide member.