The study presented is focused on the influence of carbon addition on properties of the Fe‐Mn‐Si type intelligent materials with basic composition of Fe64Mn30Si6 (wt. %). Three alloys were prepared, starting from elemental powders, with 0, 0.1, and 0.3 wt. % of carbon, at corresponding silicon content reduction. For the synthesis, the mechanical alloying, sintering, and annealing were applied. Further process involved deformation and subsequent heating in a furnace. High temperature X‐ray diffraction patterns, obtained at room temperature and up to 600°C, showed evolution of α′, γ, and ε phase peaks. The study revealed that a small carbon addition (of 0.1 wt. %), could increase shape recovery stress, even up to 1.8% after one cycle of training. The higher carbon content leads to a deterioration of the property. Also, relative density differences are observed between the sintered Fe64Mn30Si6 (wt. %) alloys with before/after annealing with/without mechanical alloying involvement.
Successful one-step manufacturing of micro-foils of NiTi shape memory compound by pulsed-current sintering of nickel and titanium is reported. Sandwich-like starting configurations of Ni/Ti/Ni (ST1, ST4), Ti/Ni/Ti (ST3), and a simple Ni/Ti (ST2) one, were used. XRD and differential scanning calorimetry (DSC) measurements revealed multistep martensitic transformation, much more pronounced for ST1 than for ST2 and ST3. SEM/energy dispersive X-ray spectrometer (EDS) measurements showed the predominant NiTi phase in ST1, ST4, and other intermetallic compounds in addition to it, for ST2 and ST3. The temperature dependence of the electrical resistance for ST4 shows a peak corresponding to the R-phase and a high residual resistivity. The shape memory effect of 100% was obtained for ST1 and ST4, with the temperature range of its recovery dependent on the initial strain. The ST2 and ST3 materials revealed brittleness and a lack of plasticity due to the dominancy of the austenite phase and/or the intermetallic compound content.