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Halil Caliskan
Bartın University, Mechanical Engineering, Faculty Member
- Jožef Stefan Institute, Thin Films and Surfaces, Department MemberUniversity of Ljubljana, Faculty of mechanical engineering, Department Memberadd
- Mechanical Engineering, Materials Science, Thin Films and Coatings, Surface Science, Sustainable Manufacturing, Hard machining, and 15 moreMetal Cutting, Magnetron Sputtering, Material Selection, TOPSIS Method, Nanostructured Hard Coatings, Cutting Tool Materials, Cutting Tool, HPPMS, Tribological Hard Coatings, Wear Behavior, Optimum Parameters, Engineering, Nanoscience, Nanotechnology, and Plasma Engineeringedit
- I’m a Mechanical Engineer with twelve-year experience. I have completed my PhD study on machine materials and manufac... moreI’m a Mechanical Engineer with twelve-year experience. I have completed my PhD study on machine materials and manufacturing technologies and I have the title of Assoc. Prof. in this field. I have performed academic works, experiments and projects in the fields of materials and machining for many years.edit
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Performance of a machined part surface depends mostly on surface finish obtained on that part. Surface roughness, residual stress, microstructure, and hardness are some characteristics of the machined surface to be taken into account.... more
Performance of a machined part surface depends mostly on surface finish obtained on that part. Surface roughness, residual stress, microstructure, and hardness are some characteristics of the machined surface to be taken into account. Deposition of a hard coating on cutting tools improves the quality of surface finish by means of protection of the tool’s cutting edge geometry together with decreasing friction coefficient and cutting temperatures. The subject of this chapter is hard protective coatings, deposited by physical vapor deposition and chemical vapor deposition methods. An extended overview of fundamental effects of hard coatings on surface finish is performed.
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Page 1. Makine Teknolojileri Elektronik Dergisi Cilt: 7, No: 4, 2010 (57-71) Electronic Journal of Machine Technologies Vol: 7, No: 4, 2010 (57-71) TEKNOLOJİK ARAŞTIRMALAR www.teknolojikarastirmalar.com e-ISSN:1304-4141 ...
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Özet Makine parçaları ve kalıpların talaşlı olarak işlenmesinde birçok kesici takım malzemesi kullanılmaktadır. Konvansiyonel işleme yöntemlerinden farklı olarak yüksek hızda kesme, kuru kesme ve sert metal işleme gibi talaşlı işleme... more
Özet Makine parçaları ve kalıpların talaşlı olarak işlenmesinde birçok kesici takım malzemesi kullanılmaktadır. Konvansiyonel işleme yöntemlerinden farklı olarak yüksek hızda kesme, kuru kesme ve sert metal işleme gibi talaşlı işleme yöntemlerinin kullanımı yaygınlaşmaktadır ve bu yüzden, işleme yöntemine uygun özelliklere sahip kesici takım malzemesinin seçilmesi önem arz etmektedir. Ancak, her kesici takım malzemesi her bir özellik için farklı performans göstermektedir ve uygulanan talaşlı işlemeye en uygun kesici takım malzemesinin seçilmesi gerekmektedir. Bu ihtiyaç doğrultusunda, bu çalışmada, 19 adet alternatif kesici takım malzemesi ve 10 adet seçim kriterinden oluşan bir karar matrisi ele alınmıştır. Kesici takım malzemelerinin yoğunluk, sertlik, akma dayanımı, elastisite modülü, basma dayanımı, kayma dayanımı, Charpy darbe dayanımı, termal iletkenlik, termal genleşme katsayısı ve maliyet değerleri seçim kriterleri olarak kullanılmıştır. Bu karar matrisindeki veriler kullanı...
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ABSTRACT The current study focuses on the microabrasion wear and microstructural properties of CoNiCrAlY coatings fabricated on nickel-based superalloy substrates using atmospheric plasma spraying (APS), high-velocity oxygen fuel (HVOF),... more
ABSTRACT The current study focuses on the microabrasion wear and microstructural properties of CoNiCrAlY coatings fabricated on nickel-based superalloy substrates using atmospheric plasma spraying (APS), high-velocity oxygen fuel (HVOF), and cold gas dynamic spraying (CGDS) methods. The microabrasion tests were performed on the samples for different durations in order to understand the wear mechanism of thermally sprayed coatings and influence of the coating microstructure on the wear mechanism. The microstructures of as-sprayed coatings and wear mechanisms on the worn coatings were investigated. Initial surface topography was examined using a surface profilometer. Coating hardness measurements were performed with a microhardness tester. The lateral fracture was observed as the wear mechanism on the samples. The wear resistance of the coatings has changed with the surface features of the samples depending on the coating production process.
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Thin hard coatings are widely used in the protection of cutting tools, dies and molds to prolong their wear resistance and lifetime. Superior properties of different coatings can be combined with multilayer design, and especially a higher... more
Thin hard coatings are widely used in the protection of cutting tools, dies and molds to prolong their wear resistance and lifetime. Superior properties of different coatings can be combined with multilayer design, and especially a higher microhardness can be obtained by nanocomposite structures. In this study, a multilayer design composing of TiAlSiN, TiSiN and TiAlN layers was applied on carbide cutting tools. The top TiAlSiN layer has a nanocomposite structure of crystalline fcc-TiAlN and amorphous Si3N4 phases. The multilayer nanocomposite TiAlSiN/TiSiN/TiAlN coating was deposited on the carbide cutting tool using an industrial magnetron sputtering system. Wear behavior of the coated tools was investigated in the milling of hardened AISI D2 steel (~55 HRc). The changes in tool wear and surface roughness as a function of cutting distance were recorded. Wear mechanisms and types were investigated using optical and scanning electron microscopy in combination with energy dispersive ...
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Nanostructured hard coatings play a significant role in protection of surfaces at working conditions. They have superior properties such as low thermal conductivity, high wear resistance and high oxidation resistance. Therefore, the... more
Nanostructured hard coatings play a significant role in protection of surfaces at working conditions. They have superior properties such as low thermal conductivity, high wear resistance and high oxidation resistance. Therefore, the adhesion of the coatings to substrate has great importance for maintaining their functions. The present study describes some results concerning the scratch behavior of nl-AlTiN/TiN nanolayer and nc-TiAlSiN/TiSiN/TiAlN multilayer nanocomposite coatings. The coatings were deposited on AISI D2, AISI H11, K600 and cemented carbide substrates by CC800/9 sinOx ML (CemeCon) industrial magnetron sputtering system. CSM Revetest scratch tester was utilized for the adhesion measurements. The scratch tests were performed under progressive load. The adhesive strength of the coatings was measured by microscopic observation, acoustic emission detection and friction force recording. Surface failures were analyzed by using optical microscope. It was found that the highes...
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Milling of hard materials is an important operation in tool production. With the hard milling operations, a decrease in the production time and in the cost of products can be obtained by the elimination of some process steps and coolants.... more
Milling of hard materials is an important operation in tool production. With the hard milling operations, a decrease in the production time and in the cost of products can be obtained by the elimination of some process steps and coolants. However, unpredictable tool life and premature failure of cemented carbide tools are major process restrictions in hard milling due to the higher cutting forces and temperatures compared to conventional machining. One of the methods used for tool life enhancement is the protection of the tools by hard coatings, therefore a selection of the cutting tool giving the longest lifetime is needed. In this study, the cutting performance tests were performed on AISI O2 (90MnCrV8) cold work tool steel (58 HRC) in order to determine the best cutting tool giving the longest tool life. Four types of tool were used during the tests for lifetime comparison, i.e. uncoated, nanolayer AlTiN/TiN, multilayer nanocomposite TiAlSiN/TiSiN/TiAlN and commercially available...
Özet Günümüzde, yüksek hızda kesme ve sert metal işleme gibi uygulamalar, sürdürülebilir imalat kapsamında büyük önem kazanmıştır. Bu uygulamalarda kullanılan kesici takımların aşınma ve oksidasyon dirençleri, fiziksel veya kimyasal buhar... more
Özet Günümüzde, yüksek hızda kesme ve sert metal işleme gibi uygulamalar, sürdürülebilir imalat kapsamında büyük önem kazanmıştır. Bu uygulamalarda kullanılan kesici takımların aşınma ve oksidasyon dirençleri, fiziksel veya kimyasal buhar biriktirme tekniğiyle üretilen tribolojik kaplamalar ile artırılabilmesine rağmen, elde edilen performanslar yeterli görülmemekte ve daha dayanıklı kesici takımlara ihtiyaç duyulmaktadır. Bu amaçla, daha iyi yüzey özelliklerine sahip kaplamaların biriktirilebilmesi için yeni kaplama teknolojileri geliştirilmekte ve kullanılmaktadır. Dengesiz magnetron sıçratma ve kapalı alan dengesiz magnetron sıçratma ile gelişen magnetron sıçratma teknolojisi, son olarak yüksek güç darbeli magnetron sıçratma (YGDMS) adı altında kullanılmaya devam etmektedir. YGDMS metodu ile biriktirilen kaplamaların, konvansiyonel kaplamalar ile karşılaştırıldığında, üstün özelliklere sahip olduğu görülmektedir. Bu çalışmada, YGDMS metodu ve bu metot ile biriktirilen kaplamaları...
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Nanolayer AlTiN/TiN hard coatings are known to have superior performance in protection of surfaces at hard working conditions due to their properties such as low thermal conductivity, high wear resistance and high oxidation resistance. In... more
Nanolayer AlTiN/TiN hard coatings are known to have superior performance in protection of surfaces at hard working conditions due to their properties such as low thermal conductivity, high wear resistance and high oxidation resistance. In the present study, the effect of nanolayered design on micro-abrasion behavior of AlTiN and TiN coatings was investigated. Nanolayer AlTiN/TiN, single layer AlTiN and single layer TiN coatings were deposited on AISI D2 substrates by CC800/9 sinOx ML (CemeCon) industrial magnetron sputtering system. Microhardness and adhesion of the coatings to the substrate were measured by nanoindentation and scratch test, respectively. The wear tests have been performed using SiC abrasive slurry by ball-cratering equipment. The friction coefficient between fixed-ball and the coatings were recorded at different normal loads and rotation speeds. Surface failures were analyzed by using optical microscope and scanning electron microscopy. The results obtained from th...
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Titanium and its alloys are widely used in aerospace and aviation industries because of their high strength-to-weight ratio, high fracture resistance and corrosion resistance at elevated temperatures. However, chemical reactivity and low... more
Titanium and its alloys are widely used in aerospace and aviation industries because of their high strength-to-weight ratio, high fracture resistance and corrosion resistance at elevated temperatures. However, chemical reactivity and low thermal conductivity of these alloys lead to adhesion and diffusion wears on carbide tools, respectively. In addition, fluctuations in cutting forces occur during the cutting process due to chip shear band formation; and chipping wear is observed at the tool cutting edge as a result. Therefore, machining of these alloys is a challenge for researchers. A common method to increase the lifetime of carbide tools is to coat them with a thin hard coating. In this study, a nanolayer AlTiN/TiN coating was deposited on carbide cutting tools using an industrial magnetron sputtering system in order to enhance their wear resistance and lifetime in milling of Ti6Al4V. The cutting tests with the coated tools were performed at a cutting speed of 50 m/min, feed rat...
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The Inconel 718 superalloy is one of the most-used nickel based superalloys in the aerospace industry due to its superior mechanical properties, for instance, high thermal and chemical resistance, and high strength at elevated... more
The Inconel 718 superalloy is one of the most-used nickel based superalloys in the aerospace industry due to its superior mechanical properties, for instance, high thermal and chemical resistance, and high strength at elevated temperatures. However, the work hardening tendency, low thermal conductivity and high hardness of this superalloy cause early tool wear, leading to the material to be called as a hard-to-cut material. Therefore, deposition of a wear resistant hard coating on carbide cutting tools has a critical importance for longer tool life in milling operations of the Inconel 718 superalloy. In this study, carbide cutting tools were coated with multilayer nanocomposite TiAlSiN/TiSiN/TiAlN coating using the magnetron sputtering technique, and wear behavior of the coated tool was investigated during face milling of the Inconel 718 superalloy under dry conditions. Abrasive and adhesive wear mechanisms were founded as main failure mechanisms. The nanocomposite TiAlSiN/TiSiN/TiA...
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Nanostructured hard coatings are widely used to improve the wear resistance of tool steels in tribological applications. Thesecoatings generally work under abrasive conditions and, therefore, a determination of their abrasive wear... more
Nanostructured hard coatings are widely used to improve the wear resistance of tool steels in tribological applications. Thesecoatings generally work under abrasive conditions and, therefore, a determination of their abrasive wear resistance has greatimportance. In this study, the free-ball micro-scale abrasion test, based on the ball-crater technique, has been used to evaluate the wear resistance of a multilayer nanocomposite nc-TiAlSiN/TiSiN/TiAlN hard coating. The coating was deposited on theAISI H11 cold-work tool steel using the industrial magnetron sputtering system. The microhardness and adhesion of the coatingto the substrate were measured with the nanoindentation and scratch tests, respectively. The wear tests have been performedusing SiC abrasive slurry on ball-cratering equipment. The crater-wear volumes have been evaluated using an opticalmicroscope (OM). An analysis of the worn craters was conducted with a scanning electron microscope (SEM). It was found thatthe nc-TiAl...
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ABSTRACT Micro-abrasion wear test is a widely used method in measurement of abrasive wear resistance of thin hard coatings. During the test, selection of test parameters has great importance in determination of the wear behavior of the... more
ABSTRACT Micro-abrasion wear test is a widely used method in measurement of abrasive wear resistance of thin hard coatings. During the test, selection of test parameters has great importance in determination of the wear behavior of the material under investigation correctly. Therefore, in this study, the effect of test parameters on the micro-abrasion behavior of CrN coating was investigated by the fixed-ball micro-scale abrasion test and modeled by response surface methodology. The coating was deposited on AISI D2 cold work tool steel using industrial cathodic arc evaporation system. The wear tests have been performed using SiC abrasive slurry. Analysis of worn craters was conducted by scanning electron microscope (SEM). It was found that the models obtained from ANOVA tables for wear volume and wear rate of CrN coating are significant and have high correlation coefficients. The rotation speed has higher influence on the wear volume of CrN coating, whereas the normal load has higher influence on the wear rate. The higher normal load increases the wear volume and decreases the wear rate. The effect of rotation speed changes according to the value of applied speed. Grooves take place by two-body abrasion in all of the craters obtained at different rotation speed and normal load values. Depth of parallel grooves in CrN coating and AISI D2 substrate decreases with the normal load and with the rotation speed.
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ABSTRACT TiN and TiAlN thin hard coatings have been widely applied on machine components and cutting tools to increase their wear resistance for more decades. These coatings have different wear behaviors, and determination of their wear... more
ABSTRACT TiN and TiAlN thin hard coatings have been widely applied on machine components and cutting tools to increase their wear resistance for more decades. These coatings have different wear behaviors, and determination of their wear characteristics at high temperature and high speed applications has great importance in selection of suitable coating material to application. In this paper wear behavior of single layer TiN and TiAlN coatings was investigated at higher sliding speed and higher sliding distances than those in literature and compared. The coatings were deposited on AISI D2 cold work tool steel substrates using a magnetron sputtering system. The wear tests were performed at sliding speed 45 cm/s using ball-on-disc method, and the wear area was investigated at seven different sliding distances (36–1416 m). Al2O3 ball was used as counterpart material. The wear evolution was monitored on confocal optical microscope and surface profilometer after each sliding test. Coefficient of friction and coefficient of wear were recorded with increasing sliding distance. It was found that wear rate of the TiAlN coating decreases with sliding distance and it is much lower than that of TiN coating at longer sliding distance. This is due to the Al2O3 film formation at high temperature at contact zone. Both coatings give similar coefficient of friction data during sliding with a slight increase in that of the TiAlN coating at high sliding distances due to the increasing alumina formation. When considering all results, the TiAlN coating is more suitable for hard machining applications.
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ABSTRACT Hard machining and high speed cutting are challenging machining processes demanded for high productivity for several decades. Hard coatings are mostly used for protection of the tool materials from severe tribological conditions... more
ABSTRACT Hard machining and high speed cutting are challenging machining processes demanded for high productivity for several decades. Hard coatings are mostly used for protection of the tool materials from severe tribological conditions in which excessive cutting temperatures and forces take place during these processes. Oxidation resistance is an important property of the hard coatings in hard machining operations due to high temperatures up to 1000°C at the cutting edge. Improvement of oxidation resistance provides longer tool life at dry cutting conditions. TiAlN-based coatings are known to have high oxidation resistance. In this paper, nanolayer AlTiN/TiN coating was deposited on cemented carbide substrates by industrial magnetron sputtering system. The need to understand the effect of nanolayered structure on the oxidation behavior of protective coatings in machining industry in terms of high temperature oxidation tests is the motivation of this investigation. The deposited coating was annealed at 1000°C with different durations. Before and after the oxidation tests, the composition, structure and phases of the coating were determined by scanning electron microscopy in combination with energy-dispersive X-ray spectroscopy and X-ray diffraction, respectively. It was found that nanolayered structure improves oxidation resistance, and thereby, it provides longer tool life.
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Thin hard coatings are widely used in the protection of cutting tools, dies and molds to prolong their wear resistance and lifetime. Superior properties of different coatings can be combined with multilayer design, and especially a higher... more
Thin hard coatings are widely used in the protection of cutting tools, dies and molds to prolong their wear resistance and lifetime. Superior properties of different coatings can be combined with multilayer design, and especially a higher microhardness can be obtained by nanocomposite structures. In this study, a multilayer design composing of TiAlSiN, TiSiN and TiAlN layers was applied on carbide cutting tools. The top TiAlSiN layer has a nanocomposite structure of crystalline fcc-TiAlN and amorphous Si3N4 phases. The multilayer nanocomposite TiAlSiN/TiSiN/TiAlN coating was deposited on the carbide cutting tool using an industrial magnetron sputtering system. Wear behavior of the coated tools was investigated in the milling of hardened AISI D2 steel (~55 HRc). The changes in tool wear and surface roughness as a function of cutting distance were recorded. Wear mechanisms and types were investigated using optical and scanning electron microscopy in combination with energy dispersive spectroscopy. It was found that the multilayer nanocomposite TiAlSiN/TiSiN/TiAlN coating provides at least 1.2 times higher wear resistance and a longer lifetime than single layer TiN and TiAlN coatings. Main wear mechanisms are abrasion and adhesion of the workpiece material on the cutting edge. As a result, wear types are notch wear and build-up-edge formation.