In this work, the formation of intermetallics in Ni-Ti system by reactive sintering at 500 and 650 degrees C was studied. Mechanism and kinetics of the reactions leading to Ni-Ti phases were determined by DTA and the application of an experimental model consisted of nickel-plated titanium. It was found that Ti2Ni phase forms already at 500 degrees C. At 650 degrees C this phase undergoes a reaction with nickel to NiTi and Ni3Ti. The reactions were determined to be diffusion-controlled. The formation of Ni3Ti contributes to the porosity evolution during reactive sintering production of NiTi alloy. (C) 2015 Elsevier B.V. All rights reserved.