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Öğe Biodegradable Biconstituent Melt-Blown Nonwovens for Air Filtration: Fabrication and Characterization(Korean Fiber Soc, 2024) Eticha, Andinet Kumella; Akgul, Yasin; Pakolpakcil, Ayben; Unlu, Oguz Kagan; Ahmed, Salih Birhanu; Cug, Harun; Kilic, AliMelt-blown polypropylene (PP) is extensively used in air filtration due to its low cost, low weight, and easy processing, but there are increasing environmental concerns due to its non-degradability. On the other side biodegradable polymers such as polylactic acid (PLA) present insufficient strength and limited toughness. Polymer blending is a well-known approach to reach optimum properties from at least two polymers. This study aims to produce biodegradable PP-PLA-based filter materials that possess enhanced elasticity and superior filtration performance. The addition of PLA raises the average fiber diameter (AFD), causing the PP-PLA filters to have AFD ranging from 0.73 to 0.91 mu m. However, the incorporation of zinc stearate (ZnSt) decreased the melt viscosity, resulting in thinner fiber formations with AFD ranging from 0.6 to 0.75 mu m for PP-PLA-ZnSt. The efficiency of the corona-charged optimized sample (double-layer 75PP-25PLA-ZnSt) showed 97.42% particle capture efficiency and filtration performance of 0.12 mmH(2)O(-1). Despite the presence of hydrophobic surfaces in all filter materials, the addition of ZnSt further improves the resistance to surface wettability. 75PP-25PLA-ZnSt filter material exhibits high stretchability, with a maximum tensile strength of 380 +/- 70 kPa. The proposed tricomponent (PP-PLA-ZnSt) approach would be used to reduce the environmental impact of non-degrading polymers.Öğe Corrosion and Wear Behaviour of Boronized high Carbon and Chromium Cast Steel(Iron Steel Inst Japan Keidanren Kaikan, 2013) Ahlatci, Hayrettin; Yargul, Gorkem; Cug, Harun; Cevik, Engin; Yasin, Suleyman; Sun, YavuzThe purpose of this study was to examine the effect of boronising heat treatment on the corrosion behaviour (in two different corrosive media) and wear properties (on two different counter sliding discs) of the DIN 1.4777 quality cast steel containing 1.7% C, 30% Cr and 1.1% Si. The steel supplied as cast was exposed to homogenisation heat treatment at 1150 degrees C for 3,5 hours and then to boronising heat treatment at 900 degrees C for 8 hours using the powder of Ekabor 2. An optical light microscope, SEM and XRD analyses were used to conduct microstructural characterisation of the steel investigated. Electrochemical potentio-dynamic polarisation measurements were taken to evaluate corrosion behaviours of the examined steels. Wear tests were conducted in a pin-on-disc type wear device by using a load between 10 N and 60 N. While the corrosion resistance of the boronising heat treated steel deteriorated by the pitting damage mechanism within corrosive media, uniform corrosion damage enhanced the corrosion resistance of the examined boronised steel. Oxidative adhesion, cracking of oxide and/or boride layer, and severe plastic deformation mechanisms were dominant during the wear tests. Severe plastic deformation and cracking of the oxide and/or boride layer caused wear mechanism to transform from mild to severe.Öğe The Effect of Nickel on the Microstructure, Mechanical Properties and Corrosion Properties of Niobium-Vanadium Microalloyed Powder Metallurgy Steels(Mdpi, 2020) Ahssi, Mohamed Ahmed Mohamed; Erden, Mehmet Akif; Acarer, Mustafa; Cug, HarunIn this study, the effects of adding Ni in different ratios to Fe-matrix material containing C-Nb-V produced by powder metallurgy on microstructure, tensile strength, hardness and corrosion behaviors were investigated. Fe-C and Fe-C-Nb-V powders containing 5%, 10%, 13%, 15%, 20%, 30% and 40% nickel were pressed at 700 MPa and then sintered in an Ar atmosphere at 1400 degrees C. Microstructures of the samples were characterized with optical microscope, scanning electron microscope (SEM) and XRD. Corrosion behaviors were investigated by obtaining Tafel curves in an aqueous solution containing 3.5% NaCl. Mechanical properties were determined by hardness and tensile testing. While Fe-C alloy and Fe-C-Nb-V microalloyed steel without Ni typically have a ferrite-pearlite microstructure, the austenite phase has been observed in the microstructures of the alloys with 10% nickel and further. Yield and tensile strength increased with nickel content and reached the highest strength values with 13% Ni content. The addition of more nickel led to decrease the strength. Analysis of Tafel curves showed that corrosion resistance of alloys increased with increasing nickel concentration.Öğe Effect of Zn and Mn Additions on the Wear Resistance of Cast Alloy Mg-5% Al-1% Si(Springer, 2017) Cug, Harun; Ahlatci, HayrettinThe effect of additions of Zn and Mn (from 0.5 to 4%) on the microstructure of alloy Mg - 5% Al - 1% Si is studied by the methods of x-ray diffractometry and light and scanning electron microscopy. The strength parameters are determined in tensile and wear tests. It is shown that particles of Mg2Si precipitate in the matrix and particles of Mg17Al12 precipitate on grain boundaries upon the introduction of low contents of Zn and Mn. Phases MgZn and Al6Mn precipitate at a high content of the additions. An optimum concentration of Zn and Mn is chosen for raising the wear resistance of alloy Mg - 5% Al - 1% Si.Öğe The Effects of Hot Rolling Process on Mechanical Properties, Corrosion Resistance, and Microstructures of Mo-Ni Alloyed Steels Produced by Powder Metallurgy(Int Inst Science Sintering (I I S S), 2024) Elkilani, Rajab Hussein Rajab; Cug, Harun; Erden, Mehmet AkifThis study examined the effects of hot rolling on the microstructure, tensile strength, and corrosion behaviors of three different alloy steels made by powder metallurgy: Fe -0.55C, Fe-0.55C-3Mo, and Fe-0.55C-3Mo-10Ni. 700 MPa pressure was applied to press the particles. The cold pressed samples were sintered in a mixed -gas atmosphere (90% nitrogen, 10% hydrogen) at 5 degrees C/min up to 1400 degrees C for 2 hours. Then, the produced steels were hot rolled with a deformation rate of 80%. The microstructures show that deformed Mo and MoNi steels have finer microstructures, better mechanical properties than undeformed Mo and Mo-Ni steels, and MoC, MoN, or MoC(N) was formed in the Mo-Ni steels. The highest mechanical properties were obtained in rolled steel samples containing Mo-Ni, followed by rolled Mo steel and rolled carbon steel samples, and then unrolled samples. Additionally, Tafel curve analysis demonstrated that alloy corrosion resistance rose as Ni concentration increased. It has also been observed that the hot rolling process improves corrosion resistance. The increase in the density value with the rolling process emerged as the best supporter of corrosion resistance.Öğe Fabrication of stretchable and high-filtration performance melt-blown nonwoven webs for PM0.3 aerosol filtration(Wiley, 2024) Eticha, Andinet Kumella; Akgul, Yasin; Pakolpakcil, Ayben; Unlu, Oguz Kagan; Cug, Harun; Kilic, AliPolypropylene (PP) is a semi-crystalline polymer that displays simple manufacturing, high stiffness, lightweight, chemical resistance, and inexpensive. However, PP has significant drawbacks, such as poor brittleness at low temperatures, high shrinkage ratio, and low impact resistance, which limit its development. Thermoplastic polyurethane (TPU) possesses recyclable and eco-friendly characteristics, along with the elasticity of rubber and exceptional mechanical properties. In this study, a flexible and high-filtration performance PP-TPU textile material was developed by melt-blowing for filtering PM0.3 aerosols. For the first time, a melt-blown PP-TPU nonwoven was used as an air filter. The fiber morphological studies exhibited that addition of 10 and 20 wt.% TPU into PP resulted in a fiber diameter increment from 0.94 to 1.24 mu m. Also, melt-blown PP-TPU forms helical fibers, which are different from fibers noticed in melt-blown PP. Corona-charged double-layer 80PP-20TPU nonwovens have a filtration efficiency of 99.25% and quality factor (QF) of 0.13 mm H2O-1 at an air flow rate of 95 L/min. Moreover, PP's tensile strength was increased by 72.22%, and elongation was raised by 38.1% with the addition of 20 wt.% TPU. Thus, PP-TPU melt-blown composites may bring novel perspectives into the design and development of high-performance filtering materials for a variety of applications.Öğe Influence of technological synthesis conditions on corrosion behaviour and mechanical properties for NiTi alloys(Emerald Group Publishing Ltd, 2023) Tuncay, Badegul; Cug, Harun; Tuncay, Tansel; Ozyurek, Dursun; Cesarz-Andraczke, KatarzynaPurposeThis study aims to investigate NiTi alloys' characterization and corrosion behaviour produced by two different powder metallurgy (PM) methods. Design/methodology/approachIt was pre-formed under a protective atmosphere at 900 & DEG;C under a force of 45 MPa and sintered for 1 h under 10-6 Mbar in an atmosphere-controlled heat treatment furnace at 1,100 & DEG;C. The relationship between microstructural properties, SEM, XRD, density, microhardness and corrosion behaviour of pre-alloyed NiTi alloys produced by two different methods with the production method was investigated. FindingsAs a result of the studies, TiO, NiTi, NiTi2 and Ni3Ti intermetallics were determined in XRD examinations. The best surface roughness was observed in the mechanically milled (MM'ed) pre-alloyed NiTi alloy compared to the pre-alloyed NiTi alloy mixed with turbula. The corrosion tests performed in 3.5% NaCl solution determined that the MM'ed pre-alloyed NiTi alloy had better corrosion resistance than the pre-alloyed NiTi alloy mixed with turbula. Pitting corrosion was visualized in the SEM images taken from the corrosion surfaces. Originality/valueTwo different PM methods produced pre-alloyed NiTi powders, and the effects of these methods on the mechanical and corrosion resistance of NiTi alloys were systematically investigated for the first time.Öğe Investigation of Microstructure and Mechanical Properties of Layered Material Produced by Adding Al2O3 to 316L Stainless Steel(Mdpi, 2023) Albahlol, Osama Albahl Alshtewe; Elkilani, Rajab; Cug, Harun; Erden, Mehmet Akif; Ozmen, Ramazan; Esen, IsmailThis study developed new advanced composite materials consisting of functional grading of 316L and Al2O3 specially designed for potential biomedical applications. Mechanical properties were characterized by tensile testing, and microstructural properties by optical microscope, scanning electron microscope (SEM), and Energy Dispersive X-Ray (EDX) analyses. The uniform mixture in the material, up to 40% by weight of Al2O3, is uniformly distributed in the 316L matrix that shows disintegration. Then, samples with 2, 3, 4, and 5 layers were produced in functionally graded 6, 7, 8, and 9 material types, respectively. The layer thicknesses were formed with an average of 900 & mu;m. The results show that new composite materials can be produced functionally using 316L and Al2O3 in a layered manner. As a result of the mechanical experiments, it has been observed that the tensile strength of the layered composite structures remains within the range of 91-191 MPa, depending on the layer type. It has been observed that the elongation varies between 3.16 and 12.46%. According to these results, the materials obtained are considered suitable for use as an alternative prosthetic material in biomedical applications. The tensile strength, % elongation of the Composition 7, and yield strength of functionally graded (316 + (316L-10 Al2O3) + (316L-20 Al2O3) + (316L-30 Al2O3)) material are 123 megapascals (MPa), 7.3%, and 111MPa, respectively, and according to the literature, the mechanical strength of human bone is very close to this composition properties.Öğe Mechanical Properties of Pattern Welded 1075-15N20 Steels(Carl Hanser Verlag, 2014) Ozkan, Furkan; Kirdan, Hakan; Kara, Ismail Hakki; Husem, Fazil; Ozcelik, Sait; Akinay, Yuksel; Cug, HarunForged welded (damascus) steels are produced by traditional methods and mostly used in the design of decorative tools. These steels are well-known for their good mechanical properties. The process for making forged welded (damascus) steel consists of stacking alternating sheets of different kinds of steel on top of each other and then forge welding them together. In this study, the steels 1075 and 15N20 were used for the forging and folding procedure. The effect of fold numbers on the microstructure and mechanical behavior were investigated. The steel consisted of both materials, 54 and 250 layers, respectively, produced by forge welding. The pattern layers are homogeneous and regular, but after the process sections with up to 54 pattern layers were irregular. Steel 1075 has a pearlitic microstructure, while steel 15N20 has a ferritic microstructure. The impact toughness and tensile strength of the folded steels improved with increasing the number of folds.Öğe Properties of Al2O3 particle reinforced composites coating on IF steel(Taylor & Francis Ltd, 2022) Demirtas, Huseyin; Cug, Harun; Elkilani, RajabIn this study, IF steel was coated by the low-pressure cold spray deposit method with different coating materials. Al, Ni, Zn, and Sn powders were used as coating matrix. All coating materials were reinforced by Al2O3 particles. Mechanical properties of the coatings were determined by three-point bending, scratch, wear tests, and hardness measurement. Micro-level defects and structure of coatings were examined by SEM, EDX, and Optical microscope analysis. All coatings were applied successfully, and the most distinct defects occurred in the Ni-matrix coating. The hardness of the Ni matrix coating was the highest, however the wear resistance was the highest for the Zn matrix coating. The lowest hardness and wear resistance were measured in the Sn matrix coating. As a result of the bending test, distinct crack formations were observed in the Zn matrix coating, unlike the others.
