Titanium carbide differs considerably from tungsten carbides, and is one of the most ideal materials for resizing cartridge cases. The difference is in the microscopic structure. Tungsten carbide if viewed under a microscope, appears as sharp irregular micrograins resembling chunks of coal or quartz, and regardless of how well the surface is finished, its inherent structure remains the same. Titanium carbide micrograins on the other hand, appear smooth and rounded, resembling the rounded stones you might find in a stream bed.
Titanium carbide has the highest hardness of any readily available carbide, and those smooth rounded micrograins present a slippery, non-galling surface that is simply unattainable with other carbides.