Browsing by Author "Cicek, Hikmet"

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Adhesion and Multipass Scratch Characterization of Ti:Ta-DLC Composite Coatings
(Elsevier Science Sa, 2018) Cicek, Hikmet; Keles, Aysenur; Totik, Yasar; Efeoglu, Ihsan
DLC (diamond like carbon) is one of the most studied coatings due to its excellent mechanical and tribological properties, desirable chemical inertness and high corrosion resistance hence it has been widely used in industrial applications for a long time. However, low adhesion and low fatigue resistance are disadvantages of this coating. In this study, we deposited Ti:Ta doped DLC graded-composite coatings on Ti6Al4V and M2 substrates and adhesion and multipass scratch behaviors were characterized. SEM, EDAX and XRD were used to determine the structural properties. Adhesion and fatigue-like behaviors were obtained by scratch tests. The results showed that the critical loads and fatigue resistance of the coatings were affected by the target currents and the hardness of the coatings and substrate.
Application of Honeycomb Pattern to Ti2AlN Max Phase Films by Plasma Etching
(Springer Heidelberg, 2024) Duran, Semih; Cicek, Hikmet; Korkmaz, Ismail Hakki; Efeoglu, Ihsan
The honeycomb pattern possesses a distinctive hexagonal structure capable of seamless repetition on a flat surface, leaving no gaps. Moreover, all arm thicknesses and angles are equal to one another. This remarkable configuration is deemed biomimetic, with numerous examples found in nature. Notably, it exhibits remarkably low density and exceptional mechanical strength. MAX phase films have gathered significant attention due to their exceptional capacity to amalgamate the essential properties of both metals and ceramics. Additionally, they possess the unique ability to effectively mend surface cracks that may arise as a result of friction-wear, restoring the material to a certain degree of integrity. In this study, Ti2AlN MAX phase thin films were deposited on M2 steel substrates by a closed field unbalanced magnetron sputtering system (CFUBMS). 750 degrees C heat treatment was applied to obtain the produced films in crystalline form. In addition, plasma etching parameters suitable for the phase structure of the deposited film were determined. With the inductive coupling plasma etching (ICP) process, the honeycomb pattern was given to the Ti2AlN MAX phase films with a continuous and smooth geometry at a depth of 2 mu m. This study gives ideas for the development of multi-coating systems in which patterns of different geometries are included in a single layer.
A Comparative Study of Fatigue Properties of Tivn and Tinbn Thin Films Deposited on Different Substrates
(Elsevier Science SA, 2017) Cicek, Hikmet; Baran, Ozlem; Keles, Aysenur; Totik, Yasar; Efeoglu, Ihsan
Transition metal nitrides, especially ternary phase films attract attention due to their high mechanical and tribological features. Besides these, fatigue properties play a very important role on the performance in service life of these types of films. TiVN and TiNbN films were deposited on M2 and H13 steel substrates by reactive magnetron sputtering system. Fatigue properties of the films were characterized via multipass scratch tests. 100, 250 and 500 cycles with bidirectional multipass scratch tests were conducted at room temperature by applying 20 N constant load. Structural properties were determined with X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. Mechanical features of the films were observed with nano hardness tests. Fatigue behaviors, deformation types, coefficient of frictions of the films and effect of different substrates were discussed comparatively. According to the results, the TiVN films showed better fatigue resistance than the TiNbN films although critical adhesion load value of the TiNbN films was higher than the TiVN films. The TiVN films generally showed ductile type cracks at the edge of the tracks and the TiNbN films showed more brittle type cracks. Additionally, the films deposited on M2 substrates exhibited better strength than those of H13 substrates.
Comparison of Structural and Wear Properties of Alsi(n-O) Films
(Inderscience Enterprises Ltd, 2023) Cicek, Hikmet; Yildiz, Kubra
The aim of this study was to produce the AlSiN and AlSiO films using sputtering technique and investigate their structural, mechanical and tribological properties comparatively. Coatings were deposited on AISI D2 steel substrates by using 5%, 10% and 15% nitrogen and oxygen gas ratios. The coatings were amorphous when they were first produced, and then heat treatment at 550? was applied to obtain a crystalline structure. In order to determine the structural, mechanical and tribological properties of the films, XRD, SEM, EDS, knoop microhardness test, 3D profilometer and pin-on-disc wear tests were performed respectively. It has been determined that the gas flow rates had a significant effect on the properties of the AlSiN and AlSiO coatings. It has also been determined that all the coatings had a very dense and columnar structure, and that the thickness values varied according to the nitrogen and oxygen gas flow rates. The hardness values of the oxide films were higher than the nitrogen films. The highest hardness value was 595 HK and the lowest friction coefficient was 0.47. In addition, the lowest wear rate was obtained at 10% nitrogen gas flow ratio. It has been observed that the tribiological properties of the oxide films were very close to nitride films.
Determining the Critical Loads of V and Nb Doped Ternary Tin-Based Coatings Deposited Using Cfubms on Steels
(Elsevier Science SA, 2017) Keles, Aysenur; Cicek, Hikmet; Baran, Ozlem; Totik, Yasar; Efeoglu, Ihsan
Transition metal nitride coatings are very attractive materials due to their hardness and toughness. On the other hand, adhesion properties of these coatings are generally low because of their brittleness. To overcome this disadvantage, these coatings are produced with different deposition techniques. In this work, V and Nb doped ternary TiN-based coatings were deposited on M2 and H13 steel substrates with closed field unbalanced magnetron sputtering (CFUBMS) system. The microstructure and thickness properties were determined using Scanning Electron Microscope (SEM). The chemical composition of the coatings was examined by Energy Dispersive Spectroscopy (EDS) and X-Ray Diffraction (XRD). The mechanical properties of the coatings were carried out by nanohardness test. The critical load values (Lc) of the coatings were pointed out using a scratch tester. The thickness values of the coatings were 400 mu and 360 nm for TiNbN and TiVN, respectively. The highest thickness, nanohardness and Lc values were obtained from TiNbN coating. The maximum nanohardness and Lc values were measured as 35 +/- 1.8 GPa and 63 N from TiNbN coating on M2 steel, respectively. On the other hand, TiVN coating on both steels showed lower nanohardness and adhesion behavior. It was clearly seen that different substrates had an important effect on microstructure and mechanical properties of coatings.
The Effect of Different Annealing Temperatures on the Mechanical and Tribological Properties of the Ti2aln Max Phase Films
(Sage Publications Inc, 2024) Cakir, Muhammet; Cicek, Hikmet; Duran, Semih; Yilmaz, Ahmet Melik; Gulten, Gokhan; Efeoglu, Ihsan
Ti2AlN MAX phase films produced at different N-2 flow rates and different annealing temperatures were deposited on 52100 steel substrates using the closed-field unbalanced magnetron sputtering technique. N-2 flow rates were changed to 2, 3.5, and 5 sccm. Due to the increasing N-2 flow rate, film thickness decreased from 2 to 1.3 mu m. Then the produced films were subjected to annealing at temperatures of 700, 750, and 800 degrees C. After the film produced at a flow rate of 2 sccm was annealed at 750 degrees C, the presence of the Ti2AlN MAX phase was determined. The binding energies of Ti 2p, Al 2p, and N 1s determined in the XPS analysis confirmed the existence of the Ti2AlN film. The friction coefficient measured for Ti2AlN MAX phase films was calculated as 0.53, the hardness value as 22.8 GPa, the elastic modulus as 291.4 GPa, and the wear rate as 2.96 x 10(-4) mm(3)/(Nm).
Effect of Post-Annealing on Structural, Tribological, and Adhesion Properties of TiW/TiWSi Graded Composite Films
(Elsevier Sci Ltd, 2025) Inanc, Ahmet Sami; Yilmaz, Ahmet Melik; Duran, Semih; Gulten, Gokhan; Cicek, Hikmet
TiW/TiWSi/TiWSiN graded composite films were synthesized on AISI 52100 steel substrates by employing a radio frequency (RF)-powered magnetron sputtering technique. Following deposition, post-annealing was applied to the films at various temperatures. X-ray diffraction (XRD) analysis revealed that the films exhibited an amorphous structure prior to annealing. Upon heat treatment, the formation of TiN crystalline phases with various orientations and planes became dominant in the structure. The crystalline formations were identified and validated by means of X-ray photoelectron spectroscopy (XPS). The A-600 film exhibited the lowest values in both friction coefficient (0.13) and wear rate (2.16 x 10-6 mm3/(N & sdot;m)) among all samples. Given these results, the A-600 film demonstrated notable wear resistance and exhibited the best tribological performance among the tested samples. Furthermore, heat treatment was found to improve adhesion performance; however, it was evident that the treatment temperature must be carefully optimized. While only the A-600 film remained intact after the scratch test, the presence of microcracks and cohesive failures in the other films indicated a loss of structural integrity. This study revealed that Ti-W-Si-N-containing films can achieve enhanced hardness, tribological, and adhesion properties following an appropriate heat treatment.
Effect of Thermal Oxidation on Structural and Tribological Properties of MoS2 Films
(Wiley, 2023) Cicek, Hikmet; Gozubuyuk, Ozkan; Efeoglu, Ihsan
The aim of this study is to investigate the structural, mechanical and tribological behaviours of thermally oxidized MoS2 films. MoS2 coatings were deposited on D2 tool steel substrates using the closed field unbalanced magnetron sputtering method (CFUBMS). The thermal oxidation process was carried out at four different temperatures. Tribological properties were determined by pin-on-disc wear tests in the atmospheric environment. It was determined that thermal oxidation temperatures affected the chemical composition of MoS2 films, but did not cause any change in film thickness. The wear rates of the samples differed depending on the oxidation temperature and the applied load. The lowest wear rate was determined as 1.97 x 10(-8) mm(3)/Nm in the oxidized film at 350 degrees C. In addition, the highest hardness value was obtained as 655 HV in the film oxidized at 400 degrees C, and the lowest coefficient of friction was obtained as 0.01 in the film oxidized at 350 degrees C.
Fatigue and Adhesion Properties of Martensite and Austenite Phases of TiNi Shape Memory Thin Films Deposited by Magnetron Sputtering
(Elsevier Science Sa, 2016) Cicek, Hikmet; Efeoglu, Ihsan
The application area of TiNi shape memory thin film is gradually increasing. Especially MEMS applications of TiNi film, such as micro-mirror, micro-pump and micro-actuator are widely used. Adhesion to the substrate and fatigue resistance of these films is particularly important for these applications. In this study, we investigated adhesion and fatigue properties of martensite and austenite phases of TiNi shape memory thin films. TiNi films were deposited on copper and Si wafers with magnetron sputtering. Structural properties of the films were determined via SEM, XRD and EDS analyses. Adhesion and fatigue properties of the films were investigated through progressive and multi-pass scratch tests. Phase transformation temperatures and hysteresis were observed with differential scanning calorimeter (DSC). Scratch test results showed that adhesion and fatigue resistance of austenite phase of TiNi film is higher than martensite phase. (C) 2016 Elsevier B.V. All rights reserved.
Investigation of Hardness, Tribological and Adhesion Properties of TiAlNiVn HEA Films Heat Treated at Different Temperatures
(Elsevier Sci Ltd, 2024) Yilmaz, Ahmet Melik; Cicek, Hikmet; Duran, Semih; Gulten, Gokhan; Efeoglu, Ihsan
TiAlNiVN high entropy alloy (HEA) films were firstly produced in the literature using the magnetron sputtering system. These films were subjected to heat treatments at different temperatures between 750 degrees C and 900 degrees C. Strong TiN and VN crystal structures were observed in all the annealed films. The composition of each element constituting TiAlNiVN HEA films was within a concentration range of 5-35 %. The presence of TiAlNiVN HEA films was confirmed by X-ray photoelectron spectroscopy (XPS) analysis. D-850 film had the highest hardness of 25.7 GPa and exhibited the lowest wear rate at 2.45 x 10(-5) mm(3)/(N.m), attributable to its lowest surface roughness (0.22) and friction coefficient (0.44). Subsequent to the heat treatment, there was a substantial enhancement in the adhesion performance of the films, culminating in a high critical load value of 80 N. This study revealed that nitride-based TiAlNiVN HEA films could be enhanced in terms of hardness, tribological, and adhesion properties after heat treatment. Considering the adhesion performance, it is anticipated that the films we have produced will be a promising alternative to traditional nitride-based coatings in challenging and complex service conditions.
The Mechanical and Tribological Properties of Ti [Nb, V] N Films on the Al-2024 Alloy
(Elsevier Science SA, 2017) Baran, Ozlem; Keles, Aysenur; Cicek, Hikmet; Totik, Yasar; Efeoglu, Ihsan
Al and Al alloys exhibit low wear resistance although they are used in a wide range of automobile and aerospace industries. Therefore, in this study, transition metal nitride films were deposited using Closed Field Unbalanced Magnetron Sputtering (CFUBMS) system on this metal alloy in order to improve the wear resistance. The structural properties of the films were analyzed by XRD, SEM, EDS and AFM. The hardness values of the films were determined with a nanohardness test. A pin-on-disc tribometer was used to determine the friction and wear behavior of the films under different conditions: 50% RH in air and argon gas. Ti [Nb, V] N films on the Al-2024 alloys exhibited very dense and columnar microstructure. The lowest surface roughness, the highest film thickness and hardness values were obtained as 49 nm, 440 nm and 12 GPa from TiNbVN film, respectively. Also, TiNbVN film exhibited the lowest friction coefficient values under different tribo-test conditions. The thickness and hardness values of TiNbN film were 400 nm and 9.6 GPa, respectively. TiVN film with the lowest thickness (360 nm) and hardness (6 GPa) showed the highest friction coefficients under both conditions. The indenter penetration values were 18.75%, 26.4% and 15.23% for TiNbN, TiVN and TiNbVN films, respectively. Wear behavior of the films was significantly affected from the film thickness, hardness, surface roughness and friction coefficient values.
Production of Honeycomb-Patterned Hybrid Ti2AlN/TiNi Films and Examination of Mechanical, Tribological, Adhesion and Fatigue Properties
(Elsevier, 2025) Duran, Semih; Cicek, Hikmet
Honeycomb-patterned hybrid Ti2AlN/TiNi films were produced on M2 and Inconel 718 substrates using a magnetron sputtering system. These films were subjected to heat treatment at 750 degrees C. In the XRD patterns of annealed films, crystalline formations corresponding to the Ti2AlN MAX phase (honeycomb edge) and super elastic TiNi (honeycomb inner) films were achieved. Mechanical properties were separately determined for each film area due to the honeycomb-patterned hybrid Ti2AlN/TiNi films having two different film areas. The film deposited on Inconel 718 exhibited the highest hardness values, with 10.2 GPa for the TiNi film and 25.4 GPa for the Ti2AlN film. Considering the results of wear tests performed both at room temperature and at high temperature, it was detected that the friction coefficients and wear rates of the films decreased by at least 50 % at high temperatures. Upon examining the adhesion performance of the films, the critical load values for the films deposited on M2 and Inconel 718 were 21 N and 26 N, respectively. According to the multi-pass scratch test results, it was observed that the film deposited on M2 maintained its structural integrity under a load of 7 N and exhibited better fatigue performance. This study proved that multi-coating components with different geometric architectures can be produced in a single layer. It also showed that such hybrid coatings exhibit good performance in machine components operating under various service conditions.
Production of TiNi/Ti2AlN Multilayer Films with Different Numbers of Layers and Evolution of Tribological and Adhesion Properties
(Wiley-VCH Verlag GmbH, 2025) Duran, Semih; Cicek, Hikmet; Yilmaz, Ahmet Melik; Efeoglu, Ihsan
TiNi/Ti2AlN multilayer films are deposited on AISI M2 steel and Inconel 718 substrates using the magnetron sputtering technique. After heat treatment at 750 degrees C, TiNi and Ti2AlN MAX phase crystal structures are obtained in these films. The effects of different layer numbers on the structural, mechanical, tribological, adhesion, and fatigue properties of TiNi/Ti2AlN multilayer films are investigated. All films' thickness is measured to be approximate to 2 mu m. The 20 layers film deposited on Inconel 718 exhibited the best mechanical properties, with a hardness of 30.6 GPa and an elastic modulus of 407 GPa. A significant improvement in the tribological performance of the films is observed with an increasing number of layers. The lowest wear rate, calculated as 1.96 x 10(-5) (mm(3) (Nm)(-1)), is observed for the 20 layers film deposited on Inconel 718 at room temperature. At high temperatures, the friction coefficients of the 16 and 20 layers films deposited on Inconel 718 decreased to 0.25. In terms of adhesion properties, the 10 layers films deposited on AISI M2 steel demonstrated the best performance with a critical load value of 45 N. The results of the multipass scratch test clearly showed that the 20 layers film deposited on Inconel 718 exhibited the best fatigue behavior among all films.
Structural and Tribological Characterization of Amorphous and Crystalline Titanium-Nickel Coatings
(Taylor & Francis Ltd, 2019) Cicek, Hikmet
The interest in titanium-nickel (TiNi) alloys has increased with the discovery of the versatile properties of these alloys. In this study, the structural, mechanical and tribological properties of amorphous and crystalline TiNi coatings were investigated. The TiNi coatings were deposited with magnetron sputtering system. The crystallization process was conducted in a vacuum heat treatment furnace. The structural properties of the coatings were investigated with XRD, SEM and EDS analyses. Micro-hardness and pin-on-disc wear tests were used to obtain the mechanical and tribological properties of the coatings. AISI D2 steel, AISI 52100 steel, Aluminum 2024 alloy and copper were used as substrate materials, hence the effects of different substrates were also investigated. The highest coating hardness was obtained as 8.5 GPa and the lowest coefficient of friction value was obtained as 0.18. The tribological tests showed that the amorphous and crystalline TiNi coatings have different coefficient of friction and wear rate and using different substrate affects these properties.
Structural and Tribological Properties of TiSin Films with Different Si Content
(Elsevier Science Sa, 2023) Cicek, Hikmet; Acar, Yunus Emre; Duran, Semih; Yilmaz, Ahmet Melik; Cakir, Muhammet
TiSiN thin films were deposited on 52100 steel and Al2024 substrates by magnetron sputtering method using Ti and Si targets in Ar+N2 atmosphere. Power values of 40 W, 60 W, and 75 W were applied to the Si target, while the voltage was constant at 370 V for the Ti target. The Si atomic ratios within the film's structure were found to vary in accordance with the increasing Si target power. The impact of varying Si atomic ratios on the structural, mechanical, and tribological properties of the films was investigated. X-ray diffraction, scanning electron mi-croscopy, hardness and wear test methods were performed. As the Si ratio increased from 10 at. % to 20 at. %, the maximum hardness value was 6.06 GPa for 52100 steel and 4.33 GPa for Al2024. With increasing Si content, the film thickness increased from 1.63 mu m to 2.05 mu m. The lowest surface roughness of the produced films was 0.069 for 52100 steel and 0.308 for Al2024. The lowest wear rate of TiSiN film was calculated at 1.63 x 10-4 mm3/(N.m).
Structure and Adhesion Properties of TiNi/MoS2 Coatings
(Elsevier Sci Ltd, 2021) Cicek, Hikmet; Akar, Ozan Can; Efeoglu, Ihsan
One of the most important features expected from protective coatings is good adhesion to the substrate. In this paper, TiNi/MoS2 functional solid lubricant coatings were deposited by closed field unbalanced magnetron sputtering system on 52100 and D2 steels. The adhesion and multipass scratch characterization of the coatings were investigated. The obtained results were analyzed in terms of deposition parameters, as well as structural and mechanical properties of the coatings. Adhesion properties of the coatings were determined by scratch tests with a progressive load. The fatigue-like behaviors of the coatings were obtained by the bidirectional multipass scratch test with a constant load. The results showed that the TiNi/MoS2 has high adhesion and multipass scratch resistance than the literature results. The coatings deposited on the 52100 steel yielded better performance.
Tribological Behaviour of Ti:Ta-DLC Films Under Different Tribo-Test Conditions
(Iop Publishing Ltd, 2018) Efeoglu, Ihsan; Keles, Aysenur; Totik, Yasar; Cicek, Hikmet; Sukuroglu, Ebru Emine
Diamond-like carbon (DLC) films are suitable applicants for cutting tools due to their high hardness, low friction coefficient and wear rate. Doping metals in DLC films have been improved its tribological properties. In this study, titanium and tantalum doped hydrogenated DLC films were deposited by closed-field unbalanced magnetron sputtering system onto M2 high speed steels in Ar/N-2/C2H2 atmosphere. The friction and wear properties of Ti:Ta-DLC film were investigated under different tribo-test conditions including in atmospheric pressure, distilled water, commercial oil and Ar atmosphere. The coated specimens were characterized by SEM and X-ray diffraction techniques. The bonding state of C-C (sp(3)) and C=C (sp(2)) were obtained with XPS. The tribological properties of Ti: Ta-DLC were investigated with pin-ondisc wear test. Hardness measurements performed by micro-indentation. Our results suggest that Ti:Ta-doped DLC film shows very dense columnar microstructure, high hardness (38.2 GPa) with low CoF (mu approximate to 0.02) and high wear resistance (0.5E-6 mm(3)/Nm).
Wear Behaviors of TiN/TiCN Composite Coatings in Different Environments
(Elsevier Sci Ltd, 2018) Cicek, Hikmet
Diamond like carbon (DLC) coatings have high wear resistance and low coefficient of friction and its features are being tried to be further developed. We deposited TiN/TiCN/DLC composite coatings on inconel substrates with closed field unbalanced magnetron sputtering system to improve the features of the conventional DLC coatings. Structural, chemical and bond types of the coating were obtained with the XRD, SEM, EDS and XPS analyses. Wear behaviors of the coatings were determined in atmosphere, distillated water and commercial oil conditions under low (2 N) and high (10 N) constant load values with using pin-on-disc tribo-test system. The wear results demonstrated that using the TiN/TiCN layers with the DLC coatings increased the load carrying capacity, decreased the CoF, and wear rates at the high load values.