We have investigated the preparation, structures, and magnetic properties of bulk Fe₂CrSi and Fe₂Cr_1-xTi_xSi Heusler alloys. Although a Cr-rich secondary phase coexists with the Heusler mother phase in stoichiometric Fe₂CrSi samples, high temperature annealing (1200°C) effectively reduces the extent of the Cr-rich secondary phase. We found that pure single-phase samples can be prepared in a narrow composition range of 22% Cr. For a Fe₂Cr_1-xTi_xSi system with Ti content x of up to 1/8, virtually single-phase Heusler alloys have been obtained. The saturation magnetization of Fe₂Cr_1-xTi_xSi decreased with increasing Ti content, while their Curie temperatures T_c remained constant.