Browsing by Author "Salur, Emin"

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Citation - WoS: 2
Citation - Scopus: 2
Anatomy of Flash Sintering in Yttria-Stabilized Zirconia Solid-State Electrolyte: High Temporal Resolution Energy-Dispersive X-Ray Diffraction Using a 200 Kev Synchrotron Probe
(Springer Heidelberg, 2023) Savkliyildiz, Ilyas; Degnah, Ahmed; Biçer, Hülya; Salur, Emin; Tsakalakos, Thomas; Akdoğan, Enver Koray
High-energy synchrotron X-ray diffraction enables ultra-rapid data collection to determine unit cell volume evolution of 8YSZ under thermal and electric field (30 V/mm). Such an approach provides unprecedented insight into the anatomy of 8YSZ's flash sintering in the 797-810 & DEG;C interval. The densification due to flash sintering occurs in 40 s during which X-ray spectra were collected every 2 s. The densification of 8YSZ was accompanied by 0.55% anelastic peak shift on (220) reflection. Concomitantly, the applied thermal and electric field led to anelastic expansion of the cubic lattice parameter (+ 0.55%) and unit cell volume (+ 1.57%). Besides, an irreversible increase in the peak intensity (+ 22.6%), a decrease in peak width (- 18.3%), and integrated peak (- 13.6%) are determined. The observed anomalies are attributed to the response of oxygen vacancy generation and redistribution to the combined electric and thermal fields.
Cyclic Oxidation Behavior and Protective Oxide Scale Formation in Stainless-Steel Alloys for High-Temperature Exhaust Valve Applications
(MDPI, 2025) Cetinkal, Salih Bilal; Atas, Mehmet Sahin; Salur, Emin; Savkliyildiz, Ilyas; Subutay, Halit; Arici, Gokhan; Alhazaa, Abdulaziz
As internal combustion engine (ICE) systems are increasingly exposed to severe thermal and oxidative environments, the oxidation resistance and structural integrity of exhaust valve materials have become critical for maintaining long-term engine reliability and efficiency. This study presents a comparative evaluation of the cyclic oxidation behavior of two candidate valve steels, 1.4718 (ferritic stainless steel) and 1.4871 (austenitic stainless steel), under service-temperature conditions. The specimens were exposed to repeated oxidation at 550 degrees C, 650 degrees C and 750 degrees C for 25 cycles in ambient air. The surface and cross-sectional morphologies of the oxide layers were analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) to investigate oxide scale composition, thickness, and growth characteristics. The oxidation behavior of both alloys proceeded in two distinct stages: an initial phase marked by accelerated oxidation, followed by a slower, more stable growth period. The extent of oxidation intensified with increasing temperature. The 1.4718 alloy developed relatively porous but compositionally stable oxide layers consisting primarily of Fe- and Cr-based spinels such as FeCr2O4 and Cr2SiO4. In contrast, the 1.4871 alloy formed a dense, adherent, dual-layered oxide scale composed of an outer Mn2O3-rich layer and an inner Cr2O3-rich layer, attributable to its high Mn and Cr content. The results underscore the critical influence of elemental composition, particularly Cr, Mn and Si, on oxide scale stability and spallation resistance, demonstrating the superior cyclic oxidation resistance of the 1.4871 alloy and its potential suitability for exhaust valve applications in thermally aggressive environments.
Citation - WoS: 10
Citation - Scopus: 12
The Effect of Ultrasonic Cleaning Upon Mechanical Properties of Metal Matrix Composites
(SPRINGER INDIA, 2021) Aslan, Abdullah; Salur, Emin; Güneş, Aydın; Şahin, Ömer Sinan; Karadağ, Hakan Burak; Akdemir, Ahmet
The aim of this study is to produce composite materials by recycling metallic chips, which are found in industry as a large amount of waste. In addition, it is aimed to investigate the effect of ultrasonic cleaning process as the consolidation behavior and mechanical properties of bulk material directly depend on the cleaning of waste metallic chips. In the present investigation, spheroidal graphite cast iron (GGG-40) was employed as reinforcement material in tin bronze (CuSn10) matrix system. GGG-40 and CuSn10 chips were cleaned by ultrasonic agitation in water for 20 and 40 min. Consolidation of the cleaned metallic chips was achieved with a hot press by applying 820 MPa pressure under 450 degrees C, and the cylindrical and prismatic metal matrix composite materials with different reinforcement ratios were successfully produced. Energy-dispersive X-ray and scanning electron microscopy analyses were carried out to determine the amount of the oxide removed from the surfaces of chips. The mechanical properties of the samples were determined by hardness, porosity, compression and three-point bending tests. According to the results of the analyses, it was found that CuSn10 surfaces were cleaned from 20%, 50% and GGG-40 surfaces from 35%, 39% oxides during 20- and 40-min cleaning time, respectively. In addition, the results of the mechanical tests revealed that increased ultrasonic cleaning time improves the consolidation quality of metallic chips and it provides successful covering of GGG-40 chips by the CuSn10 chips as a result of a better structural integrity. New machinery parts with high mechanical properties can be produced as a result of recycling of the metallic chips which are available as waste in industry by appropriate cleaning process and this situation makes this study more innovative, economical and environmentally friendly research.
Citation - WoS: 55
Citation - Scopus: 58
The Effects of Harsh Aging Environments on the Properties of Neat and Mwcnt Reinforced Epoxy Resins
(ELSEVIER SCI LTD, 2021) Aslan, Abdullah; Salur, Emin; Düzcükoğlu, Hayrettin; Şahin, Ömer Sinan; Ekrem, Mürsel
In this study, the effects of different harsh aging environments on the chemical and mechanical properties of neat and multiwall carbon nanotubes (MWCNT) reinforced epoxy resins were investigated. The neat and 1 wt% MWCNT reinforced epoxy resins were exposed to four different corrosive environments, namely deionized water, NaCl solution (10 wt% NaCl), H2SO4 solution (10 wt% H2SO4), and HCl solution (10 wt% HCl. The mass variation results revealed that the highest absorption rates were found in specimens aged in both acidic environments. The highest amount of absorption was observed in the H2SO4 environment, measured approximately 3% for neat epoxy, and 6.5% for MWCNT reinforced epoxy resin. FT-IR spectrums showed that the most affected peaks belong to specimens aged in both acidic environments. Tensile test results revealed that the aging process in H2SO4 solution and deionized water deteriorated the strength of specimens. According to the literature, it was reported that the strength of specimens aged in NaCl solution environment is decreased. However, the same trend has not been in this study. In our study, the strength of specimens aged in NaCl solution environment increased impressively by 29%, which makes this study more striking. Another important point analyzed from the tensile test results was that the MWCNT nanoparticle reinforcement adversely affects the strength of the epoxy resin. So, it can be clearly stated that the use of expensive MWCNTs as filler of epoxy resin is not useful to improve its aging resistance. The scanning electron microscope (SEM) and optical microscope images showed that acidic environments result in different fracture mechanisms from typical polymer damaged surfaces reported in available researches. (C) 2020 Elsevier Ltd. All rights reserved.
Citation - WoS: 17
Citation - Scopus: 19
Evaluation of the Role of Dry and Mql Regimes on Machining and Sustainability Index of Strenx 900 Steel
(MDPI, 2022) Aslan, Abdullah; Salur, Emin; Kuntoğlu, Mustafa
Sustainable technologies draw attention in the machining industry thanks to their contributions in many aspects such as ecological, economic, and technological. Minimum quantity lubrication (MQL) is one of these techniques that enable to convey of the high pressurized cutting fluid toward the cutting zone as small oil particulates. This study examines the potency of MQL technology versus dry conditions on the machining quality during the milling of structural Strenx 900 steel within the sustainability index. High strength and toughness properties make this steel a hard-to-cut material providing an important opportunity to test the performances of dry and MQL environments. The outcomes of the experimental data demonstrated that MQL is superior in enhancing the quality of significant machining characteristics namely surface roughness (up to 35%), flank wear (up to 94%), wear mechanisms, cutting energy (up to 28%), and cutting temperatures (up to 14%). Furthermore, after analyzing the main headings of the sustainable indicators, MQL provided the same (+5) desirability value with a dry (+5) medium. This experimental work presents a comparative approach for improved machinability of industrially important materials by questioning the impact of sustainable methods.
Citation - WoS: 104
Citation - Scopus: 119
Experimental Study and Analysis of Machinability Characteristics of Metal Matrix Composites During Drilling
(ELSEVIER SCI LTD, 2019) Salur, Emin; Aslan, Abdullah; Kuntoğlu, Mustafa; Güneş, Aydın; Şahin, Ömer Sinan
In this study, the metal matrix composite materials were produced by hot press with various production parameters. The drilling experiments were performed on computer numerical control vertical machining centre without cutting fluid. Analysis of variance (ANOVA) was carried out in order to determine the effects of the production parameters on thrust force and surface roughness of metal matrix composites drilled with different feed rate. The effect of production parameters such as temperature, pressure and reinforcement ratio were investigated, and their effects were presented. The optimal level for each production parameters was determined by 'Maximize the S/N ratio approach with a Taguchi design'. The test results revealed that the reinforcement ratio was the main factor affecting the surface roughness of the metal matrix composites for both feed rate. However, same singularity was not matter on thrust force due to close contribution rates of production parameters and high error rates of analysis. In literature, an increase on the thrust force and the surface roughness values was reported as the feed rate increased during machining. Nevertheless, in our MMCs system, the thrust force and the surface roughness values were in tendency of declination / as the feed rate increased which makes this study more novel research.
Citation - WoS: 84
Citation - Scopus: 92
Improving Mechanical Properties of Nano-Sized Tic Particle Reinforced Aa7075 Al Alloy Composites Produced by Ball Milling and Hot Pressing
(ELSEVIER, 2021) Salur, Emin; Acarer, Mustafa; Şavklıyıldız, İlyas
Considering commonly employed carbide particles, titanium carbide (TiC) is regarded as an excellent reinforcement material due to its superior physical and mechanical characteristics and particularly appropriate interfacial bonding (wetting) ability with aluminum. In this study, 5 wt.% nanoparticle titanium carbide (TiCNP) reinforced AA7075 alloy composites were produced by ball milling and hot pressing. The effects of milling time (15 min, 1 h, 1.5 h, 2 h, 10 h) on the morphologic and crystallographic properties of powders were characterized by scanning electron microscopy, particle size analysis, X-ray diffraction, and high-resolution transmission electron microscopy. It was observed that particle size and morphology varied with milling time. The results indicated that the TiCNP were gradually dispersed into the matrix as ball-milling time increased and achieved a uniform dispersion after 2 h of milling. Consolidation of the milled powders was performed via hot pressing under 400 MPa and 430 degrees C for 30 min. The effect of milling time on the microstructural and mechanical properties of the bulk TiCNP/AA7075 composites was evaluated in terms of grain formation behavior, hardness, tensile strength, and relative density results. The results revealed that three times enhanced hardness value (277.55 HB) was achieved in a 10 h milled and hot-pressed sample than initial AA7075 alloy (94.43 HB) because of the hardened nanoparticles' homogeneous distribution within the matrix along with the increment in milling time. Tensile tests showed that the 1 h milled TiCNP/AA7075 composite's ultimate tensile strength (284.46 MPa) was increased by 40 % compared with the initial AA7075 alloy (210.24 MPa). Considering test results, it was determined that the hardness values increased as a function of the milling time, but the optimum milling time, which means achieving the highest tensile strength value, was determined as 1 h. This continuous increase in hardness is attributed to the homogeneous distribution of nanoparticles within the matrix, and increased hardness of particles originated from the severe plastic deformation due to advancing milling time. However, the incoherent variation of tensile strength values with milling time suggests that the increased hardness of particles and the changes in particle morphology after 1 h of milling deteriorates the sinterability and packing properties of the powders.
Citation - WoS: 1
Citation - Scopus: 1
Investigation of Friction Coefficient Changes in Recycled Composite Materials Under Constant Load
(MDPI, 2023) Güneş, Aydın; Düzcükoğlu, Hayrettin; Salur, Emin; Aslan, Abdullah; Şahin, Ömer Sinan
The surface quality of machine elements may deteriorate over time while operating under different conditions. This deterioration adversely affects the wear behavior in the contact areas, and these materials become unusable over time. In machine elements especially, the heat transfer, wear amount and surface roughness parameters in the contact area are very important in order for the system to work efficiently. In order to understand this change, composite materials were produced by adding spheroidal graphite cast iron (GGG40) with high lubricating properties at different rates to bronze (CuSn10), which is widely used as a self-lubricating bearing material. In this study, four different mixing ratios (B60D40, B70D30, B80D20 and B90D10) and B100, which is completely produced from bronze chips, were used for comparison purposes. In addition, these produced composite materials were compared with pure CuSn10 and pure GGG40 via double-acting isostatic hot pressing, and then the results were examined. The composite materials were made at two different temperatures (400 degrees C and 450 degrees C) and three different pressures (480 MPa, 640 MPa and 820 MPa) using recycled waste chips. Composites produced by recycling waste chips both reduce costs and make a positive contribution to the natural environment. Thus, more advantageous self-lubricating bearing materials will be produced, and the efficiency will be increased in these materials. The time-dependent variation in the friction coefficient observed after the wear tests performed under constant load is explained, and the resulting surface structures are presented with SEM images and EDS analyses. After the wear tests, it was observed that the process parameters used in production effectively influenced the wear behavior. In particular, when the production pressure was low (480 MPa), the wear behavior was adversely affected because sufficient bonding between the chips could not be achieved. In addition, as the amount of GGG40 used as a reinforcement material increased, the spheroidal graphite contained in it positively affected the wear behavior. The lubricating effect provided by this spheroidal graphite reduced wear in the contact area and the friction coefficient.
Kompozit Malzemelerin Tornalanması Esnasında Oluşan Kesme Kuvvetlerinin Optimizasyonu
(2020) Salur, Emin; Aslan, Abdullah; Kuntoğlu, Mustafa; Güneş, Aydın; Şahin, Ömer Sinan
Kompozit malzemeler kullanılacağı yere göre tasarlanan ve üretilen malzemelerdir. Dolayısıyla kompozit malzemeler aynı üretim metodu kullanılarak kullanılacağı yere göre farklı üretim parametrelerinde üretilebilir. Farklı üretim parametrelerinde üretilen kompozit malzemeler farklı mekanik özelliklere sahip olacağı için bu durum kompozit malzemelerin işlenebilirlik özelliklerini etkiler. Bu sebeple kompozit malzemelerin işlenmesi esnasında oluşan kesme kuvvetlerinin tespit edilmesi ve optimizasyonu önem arz etmektedir. Bu kapsamda, 3 farklı üretim sıcaklığı (350, 400 ve 450?C) ve basıncı (480, 640 ve 820 MPa) ile 4 farklı karışım oranında (ağ. %10, ağ. %20, ağ. %30, ağ. %40) üretilen dökme demir (GGG-40) takviyeli ve bronz matrisli (CuSn10) kompozit malzemelerin kuru kesme şartlarında tornalanması esnasında kesme kuvvetlerinin optimizasyonu gerçekleştirilmiştir. Tam faktöriyel tasarım prensibi ile 36 deney yapılmış ve üç eksende kesme kuvvetleri ölçümü alınarak bileşke kesme kuvveti hesabı yapılmıştır. Deneyler esnasında kesme şartları sabit tutulmuştur (kesme hızı=50 m/dak, ilerleme=0,128 mm/dev ve talaş derinliği=1 mm). Varyans analizi (ANOVA) neticesinde bileşke kesme kuvveti üzerine en çok etkisi olan parametrenin %80 katkı oranıyla birlikte üretim basıncı olduğu tespit edilmiştir.
Mekanik Alaşımlanmış Tic ve Y2o3 Partikül Takviyeli Aa7075 Metal Matrisli Nanokompozitlerin Üretimi ve Karakterizasyonu
(Konya Teknik Üniversitesi, 2021) Salur, Emin; Acarer, Mustafa
Bu çalışmanın amacı mekanik alaşımlama yöntemi ile farklı takviye türünde (TiC ve Y2O3), farklı takviye oranlarında (ağ. %0,5, 1 ve 5) ve farklı öğütme sürelerinde (0,25, 1, 1,5, 2 ve 10 saat) AA7075 Al alaşım matrisli nano kompozit tozların üretilmesi ve bu üretilen tozların sıcak pres yardımıyla konsolidasyonunun sağlanarak hem tozların hem de üretilmiş malzemelerin detaylı karakterizasyonun gerçekleştirilmesidir. Kıyas yapabilmek adına ayrıca hazır olarak temin edilen başlangıç AA7075 matris tozu ve bu tozdan üretilen numuneye de aynı işlemler uygulanmıştır. Takviye türü, takviye oranı ve öğütme süresinin tozların morfolojisi ve kristalografik özellikleri üzerindeki etkisi taramalı elektron mikroskobu (SEM), geçirimli elektron mikroskobu (TEM), enerji dağılımlı X-ışını spektroskopisi (EDS), parçacık boyutu analizi ve X-ışını kırınımı (XRD) analizleri ile karakterize edilmiştir. Farklı parametrelerin etkisi dikkate alındığında, tozların morfolojik ve kristalografik özellikleri üzerinde en etkili parametrenin öğütme süresi olduğu tespit edilmiştir. İki farklı takviye türünde öğütülen toz grubunda da başlangıçta küresel olan tozların şekli kısa öğütme sürelerinde korunmakta iken öğütme süresinin takviye türüne bağlı olarak belirli bir değere kadar artması (1 ve 1,5 sa.) ile pulsu yapıya dönüşmüştür. Artan öğütme süresi ile bu pulsu yapılar rastgele kırılarak daha küçük toz boyutuna sahip parçacıklar oluşmuştur. Genel olarak her iki toz grubu içinde ortalama partikül boyutlarının artan öğütme süresi ile azaldığı görülmüştür ve her iki toz grubunda da en küçük partikül boyutları 10 sa. öğütme sonrasında elde edilmiştir. Hazır olarak temin edilen başlangıç AA7075 tozunun ortalama partikül boyutu 46 µm iken, 10 sa. öğütülmüş tozların partikül boyutları ise toz grubuna göre 16-20 µm aralığında değişmektedir. Bu durumun ana nedeni, Al alaşımı gibi sünek bir matris malzemesi için 10 saat gibi yüksek öğütme süresi sonunda aşırı pekleşmeye bağlı olarak küçük ve düzensiz parçacık oluşumunun artmış olmasıdır. Ayrıca, kullanılan farklı takviye türündeki nano partiküllerin matris içerisinde tamamen homojen bir şekilde dağıtılması öğütmenin son aşaması olan 10 saatlik sürede elde edilmiştir. Takviye türü ve oranına göre bu süre 1,5 ve 2 sa. olarak da değişebilmektedir. Fakat özellikle öğütmenin erken safhalarında (0,25 ve 1 sa.) ise nano takviye partiküllerinin çoğunlukla matris yüzeyinde aglomere oldukları tespit edilmiştir. Tozların X-ışını kırınım desenleri incelendiğinde ise; katı çözelti, nano partiküllerin veya küçük alaşım elementlerinin matris içinde dağılması ve bilyeli öğütme sistemi içerisinde bulunan sert bilyelerin etkisi altında tetiklenen şiddetli plastik deformasyon nedeniyle kafes üzerindeki gerilme birikiminin artması sonucu pik yoğunluklarında bir azalma ve pik genişliklerinde ise bir artma olduğu görülmüştür. Genel olarak, tozların XRD eğrilerinden yararlanarak değerlendirilen kristalografik özellikler dikkate alındığında ise; her iki toz grubu için de öğütme süresinin ve takviye oranının artması ile kristalit boyutunun düştüğü, kafes gerinimi ile dislokasyon yoğunluğu değerlerinin arttığı fark edilmiştir. Bu gruplar arasında en düşük kristalit boyutu, en yüksek kafes gerinimi ve yine en yüksek dislokasyon yoğunluğu 10 sa. öğütülmüş tozlarda elde edilmiştir. Toz boyutlarında olduğu gibi kristalografik özellikler üzerinde de en etkili parametrenin öğütme süresi olduğu tespit edilmiştir. Karakterizasyonu tamamlanan tozların konsolidasyonu 30 dakika boyunca uygulanan 400 MPa basınç ve 430 oC sıcaklık değerlerinde sıcak presleme yöntemi ile sağlanmış ve metal matrisli kompozit (MMK) malzemeler başarılı bir şekilde üretilmiştir. Ayrıca, farklı üretim parametrelerinin (takviye türü, oranı ve öğütme süresi) MMK malzemelerinin mikro yapıları ve mekanik özellikleri üzerindeki etkisi, optik mikroskop, SEM, TEM, EDS, yoğunluk ve sertlik sonuçları ile değerlendirilmiştir. Sonuçlar, aşırı plastik deformasyon sonucu sertleşen nano parçacıkların artan öğütme süresiyle matris içerisinde homojen olarak dağılması sonucu meydana gelen dispersiyon sertleşmesi nedeniyle başlangıç AA7075 alaşım malzemesine kıyasla üç kat daha fazla sertlik değerlerine ulaşıldığını ortaya koymuştur. AA7075 başlangıç tozundan üretilen numunenin sertlik değeri 94 Brinell sertlik değerindeyken (BSD) ağ. %5 TiC takviyeli 10 saat öğütülmüş numunenin 280 BSD , ağ. %5 Y2O3 takviyeli 10 saat öğütülmüş numunenin ise 260 BSD dir. Fakat benzer bir durum bağıl yoğunluk sonuçlarında gözlemlenmemiştir. Her iki grupta bulunan MMK malzemeler için artan öğütme süresi sonucu yoğunluk değerlerinde önemli oranda bir azalmanın olduğu tespit edilmiştir. Aynı zamanda, artan takviye miktarı da malzeme yoğunluklarının azalmasına neden olmuştur. Yani, en iyi yoğunluk özelliklerinin ve tatmin edici bir yapısal bütünlüğün elde edilmesi, sadece matris içindeki nano partiküllerin homojen dağılımı ile değil, aynı zamanda optimal partikül boyutu aralığı ve partikül morfolojisinin elde edilmesiyle de ilişkilidir. Yoğunluk sonuçları incelendiğinde TiC takviyeli MMK malzemeler için en yüksek yoğunluk değerleri 1 sa. öğütme sonrası elde edilmişken, Y2O3 takviyeli MMK malzeme grubunda 1,5 sa. öğütme sonrasında elde edilmiştir. Ayrıca literatürde yapılan neredeyse tüm AA7075 matris esaslı kompozitlerin çalışmaları dikkate alındığında, üretilen bu MMK malzemelerin sertlik değerlerinin diğer üretim yöntemlerinden olan geleneksel soğuk-sıcak pres ve modern üretim teknikleriyle üretilen kompozit malzemelerden çok daha yüksek olduğu bulunmuştur. Sonuç olarak, bu tez çalışması boyunca izlenen iş akışının ve elde edilen bulguların nano partikül takviyeli Al esaslı kompozitlerin mekanik özellikleri üzerinde faydalı etkileri olduğu tespit edilmiştir.
Citation - WoS: 9
Citation - Scopus: 10
Multicycle Flash Sintering of Cubic Y2o3-Stabilized Zro2: an in Situ Energy Dispersive Synchrotron X-Ray Diffraction Study With High Temporal Resolution
(Elsevier Ltd, 2022) Biçer, Hülya; Degnah, Ahmed; Salur, Emin; Şavklıyıldız, İlyas; Tsakalakos, Thomas; Akdoğan, E.Koray
The current induced unit cell volume changes, (111) Bragg peak full width at half maximum (FWHM) and its integrated intensity in 8 % Y2O3 stabilized ZrO2 (8 %YSZ) solid state electrolyte was monitored during a triple-flash sintering experiment by in situ energy dispersive x-ray diffraction using a polychromatic synchrotron probe (max, photon energy 200 keV) with 2 second temporal resolution. The first spontaneous singularity in the unit cell volume (+0.54 %) was observed at 899 °C under 15 V/mm applied field intensity, which was associated with 13 mA/mm2 current draw and an increase in density to 97 %. Following anelastic relaxation of the unit cell volume under open circuit conditions, the same applied field was applied twice in a row which resulted in additional induced singularities at 925 °C (+0.48 %) and 944 °C (+0.42 %). A floating baseline, which was above the thermal expansion baseline, was observed from 833 to 969 °C and was attributed to Joule heating. The singularity at 899 °C is associated with a sharp change in (111) FWHM and a 34 % decrease in integrated peak area that was attributed to changes in the distribution of oxygen vacancies and the changes in their concentration as induced by the applied field in the spontaneous transient stage of flash sintering. © 2022 Elsevier Ltd
Citation - WoS: 18
Citation - Scopus: 20
Optimization Study on Surface Roughness and Tribological Behavior of Recycled Cast Iron Reinforced Bronze Mmcs Produced by Hot Pressing
(MDPI, 2021) Güneş, Aydın; Şahin, Ömer Sinan; Düzcükoğlu, Hayrettin; Salur, Emin; Aslan, Abdullah; Kuntoğlu, Mustafa; Pimenov, Danil Yurievich
Surface roughness reflects the quality of many operational parameters, namely service life, wear characteristics, working performance and tribological behavior of the produced part. Therefore, tribological performance is critical for the components used as tandem parts, especially for the MMCs (Metal Matrix Composites) which are a unique class of materials having extensive application areas such as aerospace, aeronautics, marine engineering and the defense industry. Current work covers the optimization study of production parameters for surface roughness and tribological indicators of newly produced cast iron reinforced bronze MMCs. In this context, two levels of temperature (400 and 450 degrees C), three levels of pressure (480, 640 and 820 MPa) and seven levels of reinforcement ratios (60/40, 70/30, 80/20, 90/10, 100/0 of GGG40/CuSn10, pure bronze-as received and pure cast iron-as received) are considered. According to the findings obtained by Taguchi's signal-to-noise ratios, the reinforcement ratio has a dominant effect on surface roughness parameters (Ra and Rz), the coefficient of friction and the weight loss in different levels. In addition, 100/0 reinforced GGG40/CuSn10 gives minimum surface roughness, pure cast iron provides the best weight loss and pure bronze offers the desired coefficient of friction. The results showed the importance of material ingredients on mechanical properties by comparing a wide range of samples from starting the production phase, which provides a perspective for manufacturers to meet the market supply as per human requirements.
Citation - WoS: 3
Citation - Scopus: 4
A Review on Surface Morphology and Tribological Behavior of Titanium Alloys Via Slm Processing
(EMERALD GROUP PUBLISHING LTD, 2025) Kuntoglu, Mustafa; Salur, Emin; Gupta, Munish Kumar; Waqar, Saad; Szczotkarz, Natalia; Vashishtha, Govind; Korkmaz, Mehmet Erdi
Purpose-Additive manufacturing became the most popular method as it enables the production of light-weight and high-density parts in effective way. Selective laser melting (SLM) is preferred by means of producing a component with good surface quality and near-net shape even if it has complex form. Titanium alloys have been extensively used in engineering covering a variety of sectors such as aeronautical, chemical, automotive and defense industry with its unique material properties. Therefore, the purpose of this review is to study the tribological behavior and surface integrity that reflects the thermal and mechanical performances of the fabricated parts. Design/methodology/approach-This paper is focused on the tribological and surface integrity aspects of SLM-produced titanium alloy components. It is aimed to outline the effect of SLM process parameters on tribology and surface integrity first. Then, thermal, thermal heat, thermomechanical and postprocessing surface treatments such as peening, surface modification and coatings are highlighted in the light of literature review. Findings-This work studied the effects of particle characteristics (e.g. size, shape, distributions, flowability and morphology) on tribological performance according to an extensive literature survey. Originality/value-This study addresses this blind spot in existing industrial-academic knowledge and goals to determine the impact of SLM process parameters, posttreatments (especially peening operations) and particle characteristics on the SLMed Ti-based alloys, which are increasingly used in biomedical applications as well as other many applications ranging from automobile, aero, aviation, maritime, etc. This review paper is created with the intention of providing deep investigation on the important material characteristics of titanium alloy-based components, which can be useful for the several engineering sectors.
Citation - WoS: 11
Citation - Scopus: 12
Towards Analysis and Optimization for Contact Zone Temperature Changes and Specific Wear Rate of Metal Matrix Composite Materials Produced From Recycled Waste
(MDPI, 2021) Güneş, Aydın; Salur, Emin; Aslan, Abdullah; Kuntoğlu, Mustafa; Giasin, Khaled; Pimenov, Danil Yurievich; Şahin, Ömer Sinan
Tribological properties are important to evaluate the in-service conditions of machine elements, especially those which work as tandem parts. Considering their wide range of application areas, metal matrix composites (MMCs) serve as one of the most significant materials equipped with desired mechanical properties such as strength, density, and lightness according to the place of use. Therefore, it is crucial to determine the wear performance of these materials to obtain a longer life and to overcome the possible structural problems which emerge during the production process. In this paper, extensive discussion and evaluation of the tribological performance of newly produced spheroidal graphite cast iron-reinforced (GGG-40) tin bronze (CuSn10) MMCs, including optimization, statistical, graphical, and microstructural analysis for contact zone temperature and specific wear rate, are presented. For this purpose, two levels of production temperature (400 and 450 degrees C), three levels of pressure (480, 640, and 820 MPa), and seven different samples reinforced by several ingredients (from 0 to 40 wt% GGG-40, pure CuSn10, and GGG-40) were investigated. According to the obtained statistical results, the reinforcement ratio is remarkably more effective on contact zone temperature and specific wear rate than temperature and pressure. A pure CuSn10 sample is the most suitable option for contact zone temperature, while pure GGG-40 seems the most suitable material for specific wear rates according to the optimization results. These results reveal the importance of reinforcement for better mechanical properties and tribological performance in measuring the capability of MMCs.
Ultrahigh Antibacterial Response and Biochemical Activity in Mg-Sn-HA Material Systems
(Elsevier Sci Ltd, 2025) Subutay, Halit; Gunes, Eda; Erci, Fatih; Acarer, Mustafa; Salur, Emin; Arici, Gokhan; Savkliyildiz, Ilyas
The effects of metallic tin(Sn) and hydroxyapatite(HA) ceramic particles on metallic magnesium's mechanical properties and antibacterial (S.aureus) response along with bioactivity (toxicity) against D.melanogaster larvae, including the impact on survival, development, sex, longevity, were studied. Three different variations of self-assembled Mg-based materials were synthesized by mechanical alloying and densification of the samples was accomplished by hot press sintering. SEM analysis reveals that the smallest particle morphology was obtained in the Mg-3Sn alloy wherein excessive plastic deformation resulted in a monodisperse particle distribution, enabling uniform distribution of reinforcing elements. The most significant gain in mechanical properties was observed in the Mg-Sn system in which the formation of the Mg2Sn intermetallic results Brinell hardness of 184, corresponding similar to 500 % increase relative to pure Mg. The intermetallic Mg2Sn phase and its high-volume fraction in the Mg matrix leads hardening by the Orowan mechanism. In all treatment groups, the overall survival rate is >= 80 %, which shows that the produced alloys and composites are not neither toxic nor lethal to the model organisms. According to the survival rate and development time data, it was determined that the sex of the organisms shifted in favor of the first group (males) and the second group (females), while the oxidative stress (OSI) increased in organisms in contact with the first group (males). The Mg-HA and Mg-Sn-HA systems exhibit superb antibacterial properties, showing complete inhibition of S.aureus after 24-h incubation period. Overall, such alloys could have a significant impact on a range of clinical and biomedical applications because of their outstanding antibacterial properties as demonstrated in this study.
Citation - WoS: 16
Citation - Scopus: 16
Ultrahigh Hardness in Y2o3 Dispersed Ferrous Multicomponent Nanocomposites
(ELSEVIER, 2021) Salur, Emin; Nazik, Cihad; Acarer, Mustafa; Şavklıyıldız, İlyas; Akdoğan, E. Koray
Oxide dispersion strengthened Fe-based steels are one of the candidate materials for applications in future nu-clear reactors, an operation that needs superior mechanical properties and long-term microstructural stability at elevated temperatures. The effects of milling time on the hardness of nano-Y2O3 dispersed [Fe:(Cr-Mo-W-Ni-Nb-V)] nanocomposites were studied. The nanostructure, microstructure and crystallographic structure of the nanocomposites were evaluated using scanning electron microscopy (SEM), particle size analysis, X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HR-TEM) and energy dispersive spectroscopy (EDS). The nanocomposites' hardness was assessed by Vickers microhardness (HV). Milling up to 6 h yielded 200 textured plate-like particles of 200 nm thickness and 117 mu m mean particle size due to particle-particle welding. Milling for 24 h resulted in a bimodal particle size distribution of 6 mu m mean particle size due to strain hardening induced particle fracture. X-ray crystallite size of 24 h milled powder was 30 nm, corresponding to a dislocation density of 1.30 x 10(15) /m(2). Peak shift of (110) reflection with increasing milling time indicated that alpha-Fe matrix was under a compressive state of stress. Compositional fluctuations of alloying elements in the alpha-Fe matrix was detected even in 24 h milled powder by x-ray diffraction. Per TEM, uniformly dispersed similar to 20 nm Y2O3 particles of similar to 10 nm mean separation form an incoherent interface with the alpha-Fe matrix. The Vickers hardness of the nanocomposite increased from 185 to 537-a similar to 300% after 24 h of milling. Such colossal increase in hardness was attributed to concurrent size effects associated with fracture, surface effects, solid solution strengthening in multicomponent alloys, and the Orowan mechanism.
Citation - WoS: 4
Citation - Scopus: 4
Using Quadratic Multiple Linear Regression Models To Investigate the Effect of Inoculant Type and T6 Heat Treatment on Microstructural, Mechanical and Corrosion Properties of Al-Cu Alloy Produced by Casting
(Elsevier, 2023) Çetintürk, Selman; Tarakcıoğlu, Necmettin; Acarer, Mustafa; Cunkas, Mehmet; Salur, Emin
In this study, the effect of different inoculant types such as AlSr10, Al3Ti1B and Al5Ti1B and T6 heat treatment on the microstructure, mechanical properties, and corrosion behavior of Al-5 %Cu alloy were thoroughly investigated. Al-5 % Cu without inoculant, Al-5 %Cu-AlSr10, Al-5 %Cu- Al3Ti1B and Al-5 %Cu- Al5Ti1B alloys were produced by casting, and they were subjected to T6 heat treatment. Microstructures of the alloys were characterized by optical microscopy, SEM with EDX module and XRD. To determine the mechanical properties of the alloys, hardness, tensile and Charpy-V impact tests were applied. Pin on disc and immerse corrosion tests were also carried out to observe grain size effect resulted from different inoculant types on wear and corrosion properties. Sr added Al alloy shows finer grain size than the Al-5 % Cu without inoculant. However, AlSr10 inoculant does not exhibit such good results as compared to Al3Ti1B and Al5Ti1B in terms of grain refinement. When the Al3Ti1B and Al5Ti1B inoculants were compared, 5Ti added one showed finest grains in the structure. In this regard, hardness, tensile strength, and wear resistance were increased systematically with decreasing grain size. Ductility in tensile test and toughness in Charpy-V impact tests of AlSr10 and Al3Ti1B added Al-5 %Cu alloys shows lower value than Al-5 %Cu alloy without inoculant. Corrosion damage increased with decreasing grain size. Further, the statistical performance of these models was tested and the closest model to the measurements was determined. It is expected that the applied quadratic models will be the best option for predicting yield strength, and weight loss in wear and corrosion properties.