In this work the formation of intermetallics in the Ni-Ti system by reactive sintering at 800-900°C was studied. The mechanism and kinetics of the reactions, which led to Ni-Ti phases, were determined by thermal analysis, in-situ XRD and the application of an experimental model consisting of nickel-plated titanium. It was found that the formation of Ni-Ti phases below the transformation temperature of titanium is controlled by diffusion. Above this temperature, the reactions switch to the rapid Self-propagating High-temperature Synthesis (SHS) mode. Keywords: reactive sintering, powder metallurgy, NiTi V delu je bil raziskan nastanek intermetalnih zlitin v sistemu NiTi pri reaktivnem sintranju na 800-900°C. S termi~no analizo, XRD-in situ analizo in uporabo eksperimentalnega modela, nikljanega s titanom, sta bila dolo~ena mehanizem in kinetika reakcij, ki sta vodila k NiTi fazam. Ugotovljeno je bilo, da je tvorba NiTI faze pod transformacijsko temperaturo titana, nadzorovana z difuzijo. Nad to temperaturo se reakcije spremenijo na hitro rasto~i temperaturno -sintezni na~in (SHS). Klju~ne besede: reaktivno sintranje, metalurgija prahov, NiTi

This work summarizes recent results in the field of intermetallics achieved during the research in our department. The research was focused on high temperature materials, shape memory alloys and hydrogen storage materials. In the case of high-temperature intermetallics, the development of TiAl-Ti5Si3 and NiAl-Al2O3 composites and Fe-Al-Si based alloys is described. During this research, powder metallurgy using reactive sintering has been established as an innovative and promising method for easy preparation of these materials. This method is also currently being tested and optimized for NiTi shape memory alloy. Another important property of several intermetallics (as LaNi5 or Mg2Ni) is the ability to store hydrogen reversibly.

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