•Al–Ti–Nb surface alloys have been successfully obtained by electron-beam surface alloying technology.•The alloys consist of (Ti,Nb)Al3 fractions, distributed in the biphasic structure of (Ti,Nb)Al3 particles dispersed in α-Al.•The alloying speed does not affect the lattice parameters of (Ti,Nb)Al3 and, does not form additional stresses, strains etc.•It was found that lower velocity of the specimen motion during the alloying process develops more homogeneous structures.•The measured hardness of (Ti,Nb)Al3 compound reaches 775HVkg/cm2 which is much greater than the values of NbAl3. The combination of attractive mechanical properties, light weight and resistance to corrosion makes Ti-Al based alloys applicable in many industrial branches, like aircraft and automotive industries etc. It is known that the incorporation of Nb improves the high temperature performance and mechanical properties. In the present study on Al substrate Ti and Nb layers were deposited by DC (Direct Current) magnetron sputtering, followed by electron-beam alloying with scanning electron beam. It was chosen two speeds of the specimen motion during the alloying process: V1=0.5cm/s and V2=1cm/s. The alloying process was realized in circular sweep mode in order to maintain the melt pool further. The obtained results demonstrate a formation of (Ti,Nb)Al3 fractions randomly distributed in biphasic structure of intermetallic (Ti,Nb)Al3 particles, dispersed in α-Al solid solution. The evaluated (Ti,Nb)Al3 lattice parameters are independent of the speed of the specimen motion and therefore the alloying speed does not affect the lattice parameters and thus, does not form additional residual stresses, strains etc. It was found that lower velocity of the specimen motion during the alloying process develops more homogeneous structures. The metallographic analyses demonstrate a formation of surface alloys with very high hardness. Our results demonstrate maximal values of 775HV kg/cm2 and average hardness of 673HV kg/cm2.