# Preparation and Electron-Beam Surface Modification of Novel TiN Material for Medical Applications
###### Abstract  
A new approach to fabricate TiNi surfaces combining the advantages of both monolithic and porous materials for implants is used in this work. New materials were obtained by depositing a porous TiNi powder onto monolithic TiNi plates followed by sintering at 1200 \({}^{\circ}\)C. Then, further modification of the material surface with a high-current-pulsed electron beam (HCPEB) was carried out. Three materials obtained (one after sintering and two after subsequent beam treatment by 30 pulses with different pulse energy) were studied by XRD, SEM, EDX, surface profilometry, and by means of electrochemical measurements, including OCP and EIS. Structural and compositional changes caused by HCPEB treatment were investigated. Surface properties of the samples during their storage in saline for 10 days were studied and a model experiment with cell growth (MCF-7) was carried out for the unmodified sample with an electron beam to detect cell appearance on different surface locations.  
TiNi; high-current pulsed electron beam; porous coating; surface modification; EIS in saline; cell growth Article  
Preparation and Electron-Beam Surface Modification of Novel TiN Material for Medical Applications  
[PERSON], [PERSON], A.V.S.; artyukhova,[EMAIL_ADDRESS] (N.V.A.); [EMAIL_ADDRESS] (D.R.K.); [EMAIL_ADDRESS] (O.V.K.); [PERSON]DRESS] (V.N.H.)  
2 Research Institute of Science and Technology, Tokai University, Kanagawa 259-1292, Japan; [EMAIL_ADDRESS]  
3 School of Natural Sciences, Far Eastern Federal University, 690091 Vladivostok, Russia  
4 Tomsk Scientific Center, Siberian Branch of Russian Academy of Sciences, 634055 Tomsk, Russia; [EMAIL_ADDRESS]  
5 Research School of High-Energy Physics, National Research Tomsk Polytechnic University, 634050 Tomsk, Russia; [EMAIL_ADDRESS]
performance at a satisfactory level. That is why new approaches that permit to fabricate TiNi surfaces combining the advantages of both monolithic and porous materials are still highly anticipated.  
This explains why the development of TiNi-based materials for implants became increasingly active with the appearance of surface-treatment methods that use concentrated energy flows [10; 11; 12]. Providing more precise surface morphology control, such techniques permit to obtain surfaces that are more suitable for in vivo applications [13; 14]. Materials based on TiNi alloys fabricated via more conventional methods such as powder metallurgy [15; 16] (including, hot-press sintering [17], spark plasma sintering (SPS) [18; 19; 20], etc.), can be further modified using ion-plasma [21; 22], ion-beam [23; 24], laser-beam [25; 26; 27] or other similar treatments.  
Among such methods, the low-energy high-current pulsed electron beam (HCPEB) seems to be one of the most promising techniques for surface modification of TiNi-based materials [28]. Importantly, HCPEB allows for homogenization of the surface layer through the dissolution of secondary-phase particles subjected to high-energy electron flow. As a result, this leads to enhanced corrosive stability of treated surfaces when they are placed into an environment characteristic of living cells [29]. Furthermore, HCPEB may increase the surface area of treated monolithic material, which should also enhance its integration in vivo.  
In our previous work, we studied a TiNi powder obtained via the hydride-calcium reduction method [30]. The powder was shown to consist of irregularly-shaped particles with a well-developed microscopic surface [30]. In the present study, for the first time, a new material was designed and fabricated by depositing the above-mentioned porous powder onto monolithic TiNi plates followed by modification with HCPEB. The work aimed at preparing and modifying the material and investigating the changes caused by the HCPEB processing in surface morphology and composition. Both untreated and HCPEB-processed surfaces were then tested in terms of their interaction with saline, and first experiments on living cell growth were carried out.