Silicon doping is predicted to be an effective strategy to mitigate stress-induced amorphization in boron carbide. In this work, Si is directly doped into boron carbide by melting (in Ar, at >3500C) the cold pressed B4C-B-Si powders. The cooled solids are then annealed at temperatures ranging from 1500 to 2200C to see the effect of heat treatment on microstructure and Si content. Microstructural details are revealed by scanning electron microscopy (SEM). X-ray diffraction (XRD) and Raman spectroscopy are used for the assessment of Si concentration.