In this work, B4C, B4C + 5 at.% Al, B4C + B, and B4C + B + 5 at.% Al were arc melted, and the resultant solid products were characterized. Results from x-ray diffraction and scanning electron microscopy showed that adding Al alone in B4C did not result in Al doping; adding Al and B in B4C led to Al doping. Al-doping also changed the surface energy of boron carbide in the liquid state, thus altered the wettability. Transmission electron microscopy revealed that stacking faults are more likely to form in the Al-doped sample, especially in the regions where the Al concentration is high.