By utilizing the magnetic control rolling 3 d deposition device designed by us, along with vacuum continuous feeding device, we are able to deposit the boron carbide coatings on Ф 1 ~ 2 mm steel mandrels by means of electron beam evaporation. With techniques such as X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and atomic force microscope (AFM), the boron carbide microspheres annealed in different time of heat preservation were characterized. The results showed that the proportion of boron and carbon was prejudiced small, with some B loss; the influence of different heat preservation time in annealing treatment on the boron carbide microspheres morphology was significant. With the increase of heat preservation time, the roughness of boron carbide microspheres increases gradually, and there is a respective and conspicuous increase in the density and mechanical properties of boron carbide microspheres. Finally we have concluded that 1~3h is the best annealing heat preservation time.
