The method of pulsed electric current sintering (PECS) has been used to obtain dense boron carbide (B4C) and B4C‐based composite materials containing tungsten boride (W2B5). To elucidate the role of the sintering additives and the mechanism of reactive densification, three types of materials have been obtained by PECS at 1850°C and 1900°C: “pure” B4C, B4C doped with 10 wt% W2B5, and B4C doped with 10 wt% tungsten carbide (WC). X‐ray diffraction and X‐ray photoelectron spectroscopy have been used to determine crystallite size, phase changes, and the peculiarities of the chemical bonds of the densified materials. Structural and mechanical properties of the materials have been investigated using scanning electron microscopy, optical microscopy, ultrasound velocity measurements, and hardness tests. The electrochemical impedance spectra have been used to investigate the electrical properties of the PECS‐ed materials.