[en] The nucleation and crystallization processes in MgO-B₂O₃-SiO₂ (MBS) glass were studied by means of non-isothermal differential thermal analysis (DTA) and X-ray diffraction (XRD). The crystallization of pure MBS glass was bulk with a diffusion-controlled crystal growth rate (n=1.5). The addition of TiO₂ facilitated the formation of nuclei and changed the crystallization mechanism to bulk crystallization with an increasing number of nuclei (n=4). The activation energy for the crystallization of Mg₂B₂O₅ was ∼ 400 kJ/mol, and this did not change significantly with the addition of TiO₂. (author)