Figure 2 shows the SEM images of 17 mm diameter Mo rods prepared with PM Mo powder and TM Mo powder. It can be seen that the Mo rod prepared with TM Mo powder presents compact microstructure and uniform grain size, of which grain boundary binding is tight. In contrast, the Mo rod is prepared with PM Mo powder, the grain size is inhomogeneous and there are few microcracks on grain boundary. In addition, there are more sintering holes.