The effect of irradiation with ions Ar+ (energy of 1 MeV and 1.8 MeV) and He (energy of 0.6 MeV) on
the structure and mechanical properties of the vacuum-arc nitride coatings. It is shown that the level of
exposure to radiation materials can be divided into 3 classes: a) “the most persistent” - significant changes
occur only on the substructure level (as an example - multi-element system Ti-Zr-V-Hf-Nb-Ta-N), b) “the
medium resistance “- significant changes occur in the macro stress-strained state (as an example - the system
Ti-N), c) “structural variable” – significant changes in the macro-level and phase composition (as an
example, the system Mo-N).
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3513

Andreev, A.A.

Filchikov, V.E.

Gorban, V.F.

Levenets, V.V.

Lysan, D.V.

Sobol, O.V.

Stolbovoy, V.A.

Voevodin, V.N.

Electronic Sumy State University Institutional Repository

Proceedings of the International Conference  Nanomaterials: Applications and Properties VOL. 2 NO 3, 03PISERE08(4PP) (2013)   2304-1862/2013/2(3)03PISERE08(4) 03PISERE08-1  2013 Sumy State University Effect of Ion Irradiation on the Structural State of the Vacuum-Arc Nitride Coatings   A.A. Andreev 1,*, V.N. Voevodin1, O.V. Sobol2, †, V.F. Gorban3,‡, V.E. Filchikov2, V.A. Stolbovoy1, V.V. Levenets1, D.V. Lysan1   1 National Science Center “Kharkov Institute of Physics and Technology, 1, Akademicheskaya Str.,  61108 Kharkov, Ukraine 2 National Technological University “Kharkov Polytechnic Institute”, 21, Frunze Str., 61002 Kharkov, Ukraine 3 Frantsevich Material Science Problem Institute, 3, Krzhizhanovsky Str., 03142 Kiev, Ukraine  (Received 10 June 2013; published online 31 August 2013)  The effect of irradiation with ions Ar+ (energy of 1 MeV and 1.8 MeV) and He (energy of 0.6 MeV) on the structure and mechanical properties of the vacuum-arc nitride coatings. It is shown that the level of exposure to radiation materials can be divided into 3 classes: a) “the most persistent” - significant changes occur only on the substructure level (as an example - multi-element system Ti-Zr-V-Hf-Nb-Ta-N), b) “the medium resistance “- significant changes occur in the macro stress-strained  state (as an example - the sys-tem Ti-N), c) “structural variable” – significant changes in the macro-level and phase composition (as an example, the system Mo-N).  Keywords: Ion irradiation, Ions Ar +, Vacuum-arc, Nitride coatings, Multi-element system, Phase compo-sition, Substructure level.   PACS numbers: 61.82.Rx, 81.07.Bc, 61.05.cp, 61.46.Hk, 62.25. – g                                                          * aandreev@kipt.kharkov.ua † sool@kpi.kharkov.ua ‡ gvf@ipms.kiev.ua 1. INTRODUCTION  Certain elements of NPP structure are subjected to ion irradiation of different energies, resulting in their rapid degradation due to a decrease in the physical and mechanical properties of the materials from which they are made. Therefore, one of the priorities of modern materials science is the devel-opment of materials resistant to radiation damage and the potential use of radiation processing tech-nology as improving functional properties. From a position of high functionality (and espe-cially mechanical properties) recently carried out extensive studies on the use to create radiation-resistant surface coatings, refractory transition metal nitrides. This primarily refers to the finder of great practical use – vacuum arc coating of titanium nitride, which is inherent high hardness, adhesion, corrosion resistance. This explains the interest in the study of physi-cal and mechanical properties of TiN coatings sub-jected to ion irradiation. Besides titanium nitride with high energy of the covalent bond as materials for the study were chosen from MoN average bind-ing energy and the new class of materials nitride high entropy multicomponent alloy Ti-Zr-V-Hf-Nb-Ta. The paper analyzes the effect of irradiation with Ar+ (and, for comparison He+ with the energy of 0.6 MeV) to a dose of 1016 ion/сm2 (to simulate expo-sure in the work area NPP) with energies of 1 MeV and 1.8 MeV, which provides an average depth of projective path about 1 micron and 1.8 microns, re-spectively.  2. EXPERIMENTAL DETAILS  Samples were prepared using vacuum arc equip-ment "BULAT-6" provided with an additional high-voltage pulse generator.   Table 1. Modes of coatings  Series number, № Type of system Ub, V Upulse, V P, Тоrr 1 Ti-N -200 - 410-3 2 Ti-N -200 -1200 410-3 3 Mo-N -100 – 1,510-3 4 Mo-N -100 -1200 1,510-3 5 Mo-N -200 – 310-3 6 Mo-N -200 -1200 310-3 7 Mo-N -200 -2000 310-3 8 Ti-Zr-V-Hf-Nb-Ta-N -70 – 410-3 9 Ti-Zr-V-Hf-Nb-Ta-N -200 – 410-3 Labeling of irradiated samples: Ar (1 MeV) – № – 1, Ar (1,8 MeV) – № – 2, He (0,6 MeV) – № – 3  To increase the adhesive bond strength of the mate-rial and its characteristics on the stainless steel sub-strate 12X18H9T fed a constant negative bias potential value Ub = (-70 ... -200) V, and along with the constant potential supplied pulses amplitude negative potential 2 kV and 1.2 kV, duration of 10 s and a repetition fre-quency of 7 kHz. Arc current in the evaporator was  A.A. ANDREEV, , V.N. VOEVODIN, O.V. SOBOL, V.F. GORBAN, ET AL. Proc. NAP 2, 03PISERE08 (2013)   03PISERE08-2 (100 ... 110) A, nitrogen pressure 0.66 Pa. Receiving modes are shown in Table 1. Phase composition and structural state was studied by X-ray diffraction on a DRON-3M Cu-K radiation using a secondary beam graphite monochromator. De-termination of residual macroscopic stresses in the coatings was carried out by X-ray strain measurement ("-sin2" method) and its modification in the event of a strong texture of the axial type. The coatings were irradiated with ions of argon and helium an accelerator "Sokol". The hardness measure-ment was carried out using mikroindentora "Micron-Gamma" with a pyramid Berkovich load within 50 grams.  3. RESULTS AND DISCUSSION  The study of structural and phase state of coatings showed that titanium nitride with strong covalent bonds in the entire range of constant potentials fed offset Ub  (-70 ... -200) V is formed in a single-phase structural state of titanium nitride with the preferred orientation of crystallites (111) [1]. The increase in Ub leads only to an increase in the degree of perfection of texture, which affects in reducing the spread of angular disorientation of crystallites of 19 (half-width of the rocking curve) at Ub  -70 V to 10.5 at Ub  -200 V.  30 40 50 60 70 80200040006000  (222) TiN(311) TiN(220) TiN(200) TiN32I, arb. un.2, deg.1(111) TiN  Fig. 1 – X-Ray diffraction spectra coating system Ti-N series 1: Unexposed – 1, 2: irradiated – 1-1 (1 MeV) and 3: 1-2 (1.8 MeV)  Analysis of the diffraction spectra of the Series 1 (before and after irradiation, Ar) showed that not fun-damentally changing the phase composition of the coat-ing (Fig. 1a), the irradiation causes a change in stress condition (the shift of the peaks) and the characteris-tics of the substructure (the broadening of the peaks). Study of the substructure of the characteristics de-fined by the approximation of the profile shape Cauchy function shown that irradiation leads to a decrease in the average grain size of crystallites of 100 nm in its initial state to 45 nm and 38 nm, respectively, at differ-ent irradiation energies Ar. Microstrain equilibrated grain volume is also changed by irradiation. With in-creasing irradiation energy it varies from 0.52 at baseline to 0.58 after the exposure to the maximum energy. Analysis of the diffraction spectra of the two series of samples (before and after irradiation with Ar) showed that after the pulse action (1200 V) does not change the phase composition of the coating (Fig. 2a). The change in the position of distant reflections (Fig. 2b). They shift to larger angles due to changes in the stress - strain state, which indicates a decrease in the value of condensation of compressive stresses in the coating.  30 40 50 60 70 800200040006000   (111) TiN(200) TiN(220) TiN(311) TiN(222) TiNI, arb. un.2, deg.12a75 76 77 78 79 800200040006000   (222) TiNI, arb. un.2, deg.12b  Fig. 2 – X-Ray of diffraction spectra coatings of series 2. Unexposed (1) irradiated – 2-1 (2). a – general view of the spectra, b – a site distant reflex (222)  The study of the characteristics substructure, which is similar to the Series 1 marked by irradiation de-creases the average grain size of the crystallites from 110 nm to 38 nm. In this case, unlike the Series 1 to Series 2 microstrain decreases from 0.58 to 0.38. Investigation of the stress-strain state of «-sin2» - method showed that the Ar irradiation with the high-est energy of samples of series 2 leads to a strong re-laxation of the stress-strain state of compression de-formation of -2.11 in the initial state (after deposi-tion) able to -1.38 - after irradiation .. In molybdenum nitride metal component (Mo) has a larger atomic weight than titanium and considerably weaker covalent bond with the metal atoms by nitrogen atoms. This is manifested in the difference in not only structural, but also the phase state of coatings. Fig. 3 shows plots of the diffraction spectra of coatings Mo-N, received at different potentials bias -100 V and-200 V, as well as applying a pulsed bias potential.    Proc. NAP 2, 03PISERE08 (2013)   03PISERE08-3 30 40 50 60 70 800400080001200016000(112)-MoN(220)-MoN(211)-MoN(300)-MoN(111)-MoN(101)-MoN(110)-MoN(311)-Mo2N(200)-Mo2N432  I.21(111)-Mo2N  Fig. 3 – X-Ray diffraction spectra of samples of Mo-N, series 3 (spectrum 1), 5 (spectrum 2), 6 (spectrum 3) and 7 (spectrum 4)  As can be seen from the diffraction spectra with less potential bias -100 V shaped -Mo2N phase with fcc metal sublattice, the NaCl-type structure with a char-acteristic [2] for this phase of the preferred orientation (311). If Ub  -200 V occurs in the formation of a new phase MoN with a hexagonal lattice of the space group P6/mmm, referred to as -MoN phase. No pulse impact of texture (101), which is at the highest pulse action Upulse  2000 V is changed to (110). Under the irradiation of the coatings obtained with Ub  -100 V with -Mo2N phase and texture (311) (phase composition and texture effects when switching is not changed) are the relaxation stress state and a decrease in crystallite size of up to 5 ... 7 nm. Irradiation coatings obtained with high Ub  -200 V leads to stronger changes accompanied by a reorienta-tion of crystallites in series samples 6 and 7 obtained by the impact impulse further. Thus, in the sample 6 series irradiation leads to the formation of preferred orientation (112), and a series of 7 - (101). Note that unlike titanium nitride for which irradia-tion from erosion not noticeable to evident erosion mo-lybdenum nitride surface after irradiation (Fig. 4).   a  b  Fig. 4 – View of the surface of the sample 7: a, before irradiation, b-after irradiation (1 MeV, Ar)  The least impact on the initial state of the materi-al had exposure high entropy nitride alloy. In the initial state in the coatings formed of the cubic phase with a lattice-type structural NaCl, characteristic of the titanium nitride, which also increases with Ub amplified texture (111) – (Fig. 5).  30 40 50 60 70 80010000200003000040000500006000070000(220)(311)(220)2  I21(111)(200)  Fig. 5 – Land diffraction spectra of samples of Ti-Zr-V-Hf-Nb-Ta-N, series 8 (spectrum 1), 9 (spectrum 2)  At high bias potential is increased in the lattice re-laxed section of 0.443 nm Ub  -70 V to 0,445 nm Ub  -200 V, and also noted a higher macrostrain -2.8 com-pared to -2.25 at smaller Ub. Even the most intense radiation Ar -1,8 MeV leads to a small relaxation of the stress state (about 5), which appears to be associated with a fairly heavy masses of metal components high entropy alloys. At the substruc-ture level the impact of irradiation effect on reducing the microstrain and a particulate formation structure, which in the case of multi-alloys can be considered a transition to a system equilibrium state. It should be noted that in case a strong texture in Ub  -70 V main radiation expo-sure has been reduced to a substantial reduction in the average crystallite size of 96 nm to 53 nm. Test results by indentation presented in Table 2 showed that irradiation binary coating systems Ti-N and Mo-N causes degradation of mechanical properties. More-over, to the greatest extent it affects the coating obtained in the dual circuit supplying negative bias potentials: a permanent and high-voltage pulse.   A.A. ANDREEV, , V.N. VOEVODIN, O.V. SOBOL, V.F. GORBAN, ET AL. Proc. NAP 2, 03PISERE08 (2013)   03PISERE08-4 Table 2. The results of the test indentation method nitride coatings before and after exposure.  Series number, № H, GPa E, GPa 1 36 433 1-1 33 433 1-2 28 420 1-3 30 400 2 44 480 2-1 33 415 2-2 22 422 2-3 27 402 3 40 400 3-1 36 340 3-2 38 380 3-3 33 320 4 44 410 4-1 39 350 4-2 34 350 4-3 30 340 5 41 398 5-1 36 358 5-2 39 374 6 39 390 6-1 30 268 6-2 38 358 7 42 398 7-1 41 399 7-2 38 382 8 39.5 355 8-1 40 475 8-2 45 487  Unlike binary, high entropy multielement alloy showed not only its mechanical resistance character-istics to the radiation, but their growth. The reason for the latter can not only be ordered components in the metal sublattice irradiation, but reduction in the average grain size. Thus, the greatest structural instability under ir-radiation showed a coating of Mo-N in which there have been significant changes, both on the substruc-ture level and at the level of the macro stress-strained  state, and the phase-structural level as a change in the phase composition at higher Ub and preferred orientation with additional exposure to Upulse and irradiation. The coating of titanium nitride, obtained at a constant negative potential bias of -200 V, and in the absence of the action of high-voltage (-1200 V) pulsed bias potential exposure without changing the phase composition and preferred orientation in varying degrees change their mode of deformation and sub-structural characteristics depending on with or without high-voltage pulse causes deposition coat-ings. In the case of multi-element high entropy nitride alloys effect of irradiation has a significant effect only on the substructure level. Moreover, such ef-fects, indicating the atomic ordering of the metal atoms and the reduction in the average size of the crystallites increases the mechanical properties of the coating, in particular by increasing the hardness of more than 10.   REFERENCES  1. O.V. Sobol’, A.A. Andreev, S.N. Grigoriev, V.F. Gorban’, M.A. Volosova, S.V. Aleshin, V.A. Stolbovoi, Metal Science and Heat Treatment,  54 No3-4, 195 (2012).  2. O.V. Sobol’, A.A. Andreev, V.A. Stolbovoi, V.E. Fil’chikov, Technical Physics Letters, 38 No2, 168 (2012).   

Effect of Ion Irradiation on the Structural State of the Vacuum-Arc Nitride Coatings

Effect of Ion Irradiation on the Structural State of the Vacuum-Arc Nitride Coatings

Abstract

Similar works

Full text

Available Versions

Electronic Sumy State University Institutional Repository