RESULTS

        During the research-development project CEEX no. 249/2006 entitled „Advanced Research for New Superhard Thin Films for Wear Resistant Tools” – ANTIWEAR, the following novel results were obtained:        

       Synthesis of new materials for targets, a national novelty, of Ti-Si (with high Si content, over 12%) and composite based Ti-Si (with Al, Cr,B,Y content as alloying  elements: TiAlSi, TiAlSiCr, TiAlSiB, TiAlSIY). Resulted materials, with chemical compositions as element of novelty, have proved superior properties in terms of physical-mechanical characteristics in comparison with common used alloy based titanium (Ti6Al4V, Ti5Al2.5Fe).

        Preparation of targets, using novel unconventional technologies of powder metallurgy, has been made through the following methods:

-     TiSi and TiAlSi targets: mechanical alloying of powders and sintering

-     TiAlSiCr, TiAlSiB and TiAlSiY targets: injection in mould, delloying and sintering of the plastified compounds from composite powders.

        Injection moulding, that is part of the “near-net-shapes technologies”, allows the achievement of several products with complex geometry using special raw materials which are in plastic state under the specific conditions of form operation. During delloying and sintering, a uniform distribution of density into formed sample and a low stress level, due to reduced pressures of forming, were obtained. Also, samples with complex geometry that is close to the final one are possible to be manufactured. In order to obtain high quality finished goods, metal powders with fine grains were used.  

      Deposition of new nanocomposite superhard thin films in single layered structure as nc-TiSiN, nc-TiAlSiN and nc-TiAlSiXN, (X= Cr,B,Y) and multilayered structure as nc-SH/Me (Me=Ti,Cu,Ni) has been taken into account in order to improve the wear resistance and to increase the cutting performance of tools subjected to severe working conditions. Nanocomposite superhard coatings were obtained using a PVD method based on cathodic arc evaporation, that represents an element of novelty, because until now these films were deposited only by high-temperature CVD (TiSiN and TiAlSiN) or reactive sputtering (TiSiCrN and TiSiBN). Quinternary nanocomposite films of the type TiAlSiXN (X= Cr,B,Y)  and also  the alternate nc-SH/Me films (nc-SH being nc-TiSiN or nc-TiAlSiN and Me =Ti,Ni or Cu) are a novel film architecture which was not proposed and analyzed so far.

      The complex characterization of the coatings includes advanced and modern investigation methods such as XPD, GDOES, AES and XRD techniques, SEM electronic microscopy and profilometry. From the evaluation of microchemical, microstructural, mechanical and tribological characteristics of different nanocomposite types investigated during the project, the TiAlSiCrN quinternary compound was selected to be deposited on two cutting tools types (shank end mills and drills). For the testing procedure, the maximum axial force and moment of torsion on drilling for mills and drills, respectively, were chosen as significant parameters.    

        Elements for economic development

As a result of the research carried out in this project, the following technologies for increase the performance of cutting tools coated by superhard thin films can be appreciated to have a high potential for technological transfer:

• technology for the synthesis of nc-TiSiN, nc-TiAlSiN and nc-TiAlSiXN (X=Cr,B,Y) superhard nanocomposite coatings in single layered structure,
• technology for the synthesis of nc-SH/Me (Me=Ti, Cu, Ni) superhard nanocomposite coatings in multilayered structure.  

        Selective references – published papers and articles presented at conferences by the consortium team

 1. Influence of Bilayer Period on the Characteristics of Nanometre-Scale ZrN/TiAlN Multilayers, A.Vladescu, A.Kiss, A. Popescu, M.Braic, M.Balaceanu, V.Braic, I.Tudor, C. Logofatu, C.C.Negrila, R.Rapean, J. Nanosci. Nanotechnol. 8, 717–721 (2008)

2. Characteristics of Ti-Nb, Ti-Zr and Ti-Al containing hydrogenated carbon nitride films, M.Balaceanu, V.Braic, M.Braic, C.N.Zoita, A.Kiss, A.Vladescu, trimisa spre publicare la Solid State Sciences

3. Plasma deposition of TiC/a-C:H multilayer with Ti-TiC graded interlayer, V.Braic, M.Braic, C.N.Zoita, A.Kiss, A.Vladescu, trimisa spre publicare la Vacuum

4. Tribological behavior of TiSiN/Ti and TiSiN/Cu multilayer coatings, I. Tudor, A. Popescu, R.G. Ripeanu, A.C. Drumeanu, V. Braic, M. Balaceanu, A. Vladescu, M. Braic, trimisa spre publicare la J.Balkan  Tribo. Assos

5. Metal working fluids based on soybean oil and synthetic esters used for turning operations, A.C.Drumeanu, R.G.Ripeanu, M.Luca, G.M.Matei, J.BalkanTribo.Assos, 4, vol.14, 2009.

6. Establish the influence of soybean oil above wear behaviour of cutting tools durability, R.G. Rîpeanu, A.C. Drumeanu, M. Luca and L. Rîpeanu, J.Balkan  Tribo. Assos., book 3 or 4, vol.14, 2009.

7. Research about the efficiency of active anode protection at centrifugal pumps, R.G. Rîpeanu, I. Tudor, F. Dinu, J.Balkan  Tribo. Assos, book 4, vol.14, 2009.

8. Tribological behavior of TiSiN/Ti and TiSiN/Cu multilayer coatings, I. Tudor, A. Popescu, R.G. Ripeanu, A.C. Drumeanu, V. Braic, M. Balaceanu, A. Vladescu, M. Braic, J.Balkan  Tribo. Assos, book 1, vol.15, 2009.

9. Synthesis and characterization of multilayered TiSiN/Ni hard coatings, M.Btraic, M.Balaceanu, V.Braic, A.Vladescu, V.Malinovschi, A.Popescu,  trimisa spre publicare  Plasma Processes and Polymers 2008

10. Superhard nanostructured coatings designed to be used as protective coatings for Wear Resistant Tools, V.Braic, M.Balaceanu, C.Zoita, A.Kiss, C.M.Cotrut, M.Braic, S.Zamfir, A.Vlădescu, Bull.Trans.Univ.of Brasov series A, vol.4, pp. 518-522, 2007

11. TiAl powders synthesis and processing by modern technologies of powder metallurgy, I.Carceanu, Cr. Coman, M.Braic, M.Balanescu, I.Nedelcu, Revista Metalurgia International, Editura F.M.R., nr.1/2008, p.12

12. Synthesis and characterization of reactive arc plasma deposited TiSiN coatings, V.Braic, M.Balaceanu, A.Kiss, C.N.Zoita, A.Vladescu, I.C. Vasiliu, M.Braic, 14th Inter.Conf.- CPPA, 14-18 septembre 2007, Brasov, Romania

13. Influence of chemical composition on properties of TiSiN, TiAlSiN and TiZrSiN coatings, A.Kiss, V.Braic, C.N.Zoita, M.Balaceanu, A.Vladescu, A.Popescu, M.Braic, R.Rapeanu, Inter.Conf. NANOSMAT 2007, 9 – 11 July 2007, Algarve – Portugal

14. Consideration concerning the elaboration of some complex materials from TiAl systems, I.Carceanu, A.Popa, I. Roceanu, G.Cosmeleata, Euromat 2007, 10 – 13 september 2007, Nurnberg, Germany

15. About the structure and properties of heavy alloys for special use, I.Carceanu, A.Popa, I.Roceanu, G.Cosmeleata, I.Nedelcu, ECCE-6, “6-th European Congress of Chemical Engineering, Conference CD, 16-21 sept. 2007, Copenhagen, Danemarca.

16. On the deposition and characterization of TiSiN  coatings using the reactive cathodic arc method, V.Braic, M.Balaceanu, A.Vladescu, A.Kiss, C.N.Zoita, M.Braic, Physics Conference TIM-07, 23-24 Noiembrie 2007, Timisoara, Romania.

17. Tribological behavior of TiSiN/Ti and TiSiN/Cu multilayer coatings, I. Tudor, A. Popescu, R.G. Ripeanu, A.C. Drumeanu, V. Braic, M. Balaceanu, A. Vladescu, M. Braic, 6th International Conference “Balkantrib 08”, 12-14 iunie 2008, Sozopol, Bulgaria.

18. Corrosion behavior of arc plasma deposited Ti/TiSiN and Ti/TiAlSiN multilayered coatings, R.Zamfir, C.M.Cotrut, A.Molagic, A.E.Kiss, S.Zamfir, Junior Euromat 2008, 14-18 July, Lausanne, Switzerland

19. Effects of titanium, aluminium and silicon powders and its compounds on human health, I.Carceanu, V.Braic, M.Braic, A.Vladescu, C.M.Cotrut, „5th SETAC World Congress 2008” , 3-7 August 2008, Sydney, Australia.

20. Complex multifunctional materials for special application, I.Carceanu, G.Cosmeleata, A.Popa, I.Nedelcu, E.Jalbă, P.Neagu Manicatide, I.Roceanu, Inter. Conf. MFMS 2008, 26 iulie – 02 august 2008, Hong Kong, China.