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Öğe Applicability of different powder and polymer recipes in a new design powder injection molding system(Walter De Gruyter Gmbh, 2021) Cicek, Bunyamin; Sun, Yavuz; Turen, Yunus; Ahlatci, HayrettinProduction methods are changing day by day with the developing technology. Based on this idea, a new production logic and machine have been developed owing to polymer-supported powder injection molding (PIM). The ability of this newly designed machine (newPIM) to mold metal or ceramic powders supported by polymer binders is discussed in this study. By taking advantage of the polymer properties such as fluidity and sticking, powders are molded with a specially developed machine with high gas pressure in certain sizes. In this study, in which many parameters are processed from feedstock (FS) production to molding; metals Mg/316L and ceramics SiC/SiO2 powders have been used in different powder sizes and structures. In the newPIM process, polymers were included in four different recipes. Paraffin wax (PW), polyethylene glycol (PEG), polypropylene (PP), ethylene-vinyl acetate (EVA), poly-methyl methacrylate (PMMA) and low-density polyethylene (LDPE) have been employed in the FS with different combinations. From FS production to the molding stage; pressure, microstructure examination, weight loss, and density change features were investigated. The result indicated that the best FS and molding was obtained by the PEG+PMMA polymer composition formed with a spherical powder with a diameter below 40 mu m. The compression force of the FS in this composition was observed at approximately 3.4k N values.Öğe A basic study on artificial aging in Mg-10Al12Si+1Pb alloy(Iop Publishing Ltd, 2020) Cicek, Bunyamin; Aydogmus, Tuna; Sun, YavuzIn this study, research has been made on the aging of metal matrix composite materials produced by the in situ casting system. Mg matrix composite material was produced by the in situ casting system. In this study, 90%Mg + 10% Al12Si (wt) ingot casting was performed for alloy formation and 1% Pb was added as an alloying element to the melted structure. This study aims to examine the effect of the artificial aging (AA) process on hardness and microstructure after alloying and composite of Mg metal. The in situ casting system was used in the casting of Mg alloy under the Ar gas atmosphere. The material after required casting homogenization process; for the AA process, they were embedded in a powder graphite filled vessel and kept at 350 degrees C for 1 h and then quenched (with 25 degrees C water). Later; after quenching, the materials were kept at 150 degrees C for 2, 4, 12, 16 and 24 h and aged samples were obtained. Microstructure images were obtained from the samples by scanning electron microscope (SEM) and light optical microscope (LOM) and then the hardness values of the micro hardness device were measured. Grain structure because of AA heat treatment; showed changes according to un-aging material. The hardness value is directly proportional to the increasing aging time of the materials applied to the AA process; it was found that the levels increased approximately to 45% (86HV to 125HV) compared to the un-aging material and passed to the fixing phase.Öğe Bio-properties of Mg-RE alloys: an applied study on cytotoxicity and genotoxicity(Taylor & Francis Ltd, 2024) Djebari, Kenza; Turen, Yunus; Elen, Levent; Ahlatci, Hayrettin; Bozer, Busra Moran; Cicek, BunyaminThis study presents a comprehensive review of magnesium alloys with rare elements. It discusses Mg-RE alloys and includes an experimental process. Thus, the data obtained by examining Mg-RE alloys provided a better interpretation of the experimental study. In this study's investigation report, Mg-RE alloys were thoroughly analyzed. In the experimental part, the cytotoxic and genotoxic results of the rare elements added to the Mg-Zn-RE master alloy are discussed. Experiments were carried out by adding Nd and Ce to this master alloy in inverse proportions. In cytotoxic data, it was observed that the viability rate in bacteria increased by up to 200%. In addition, significant genotoxic results of Mg-RE alloys were obtained, which are uncommon in the literature. As a result, a new perspective on Mg-RE alloys has been created. Cette & eacute;tude pr & eacute;sente un examen complet des alliages de magn & eacute;sium contenant des & eacute;l & eacute;ments rares. Elle discute des alliages Mg-ER et comprend un proc & eacute;d & eacute; exp & eacute;rimental. Ainsi, les donn & eacute;es obtenues en examinant les alliages Mg-ER ont fourni une meilleure interpr & eacute;tation de l'& eacute;tude exp & eacute;rimentale. Dans le rapport d'investigation de cette & eacute;tude, on a analys & eacute; & agrave; fond les alliages Mg-ER. Dans la partie exp & eacute;rimentale, on discute des r & eacute;sultats cytotoxiques et g & eacute;notoxiques des & eacute;l & eacute;ments rares ajout & eacute;s & agrave; l'alliage m & egrave;re Mg-Zn-ER. On a r & eacute;alis & eacute; des exp & eacute;riences en ajoutant du Nd et du Ce & agrave; cet alliage m & egrave;re en proportions inverses. Dans les donn & eacute;es cytotoxiques, on a observ & eacute; que le taux de viabilit & eacute; des bact & eacute;ries a augment & eacute; jusqu'& agrave; 200%. De plus, on a obtenu des r & eacute;sultats g & eacute;notoxiques significatifs des alliages Mg-ER, qui sont peu communs dans la litt & eacute;rature. Par cons & eacute;quent, on a cr & eacute;& eacute; une nouvelle perspective sur les alliages Mg-ER.Öğe The Cytotoxic and Genotoxic Assays of Mg-Ag Alloy Doped with Zn, Ca, and Nd Elements(Springer, 2023) Elen, Levent; Turen, Yunus; Cicek, Bunyamin; Bozer, Busra Moren; Saud, A. Najah; Koc, ErkanMagnesium alloys are being studied for their potential as biodegradable metals, and there is a growing need for multipurpose materials, such as those with more than one use. Binary Mg-Ag alloys were developed as implant materials, combining the beneficial qualities of magnesium with silver's well-known compatibility feature. The result shows that as the amount of the added Ag in the cast alloys increased, the secondary phases (Mg4Ag and Mg54Ag17) that appeared in the structure became more pronounced, and the grains became finer. The best percentage of Ag was found to be 3%, so Ca, Zn and Nd were added, and a study of the biocompatible Mg-3Ag alloy's cytotoxicity and genotoxicity showed that the alloy is safe for cells. In conclusion, 1/1 (total material concentration) cell viability for QE-30, QZ-30, QX-30, and QZEX3000 was 79.39 +/- 1.85, 106.46 +/- 1.99, 93.55 +/- 2.4, and 141.76 +/- 2.71%, respectively. Reducing material concentration by 50% (application at 1/2 concentration) raised viability to 96.83 +/- 1.35, 108.40 +/- 1.92, 124.71 +/- 2.76, and 129.05 +/- 3.5%, indicating the as-cast Mg + 3%Ag + 0.5% Nd-Ca-Zn alloy was extremely biocompatible.Öğe The effect of graphene-nanoplatelet and nano-teflon on mechanical properties of UV photo-resin 3D printer products(Taylor & Francis Inc, 2022) Karaca, Tunahan Hakki; Cicek, Bunyamin; Aydogmus, Tuna; Sun, YavuzIn this study, a photo-resin 3D printer was used as an example of the additive manufacturing method. The aim of the study is to improve the mechanical values of resin printer products. For this purpose, the change of mechanical values with the effect of nanostructures added to the resin by a special mixing method was investigated. Micro images, surface quality, and layers of the products were analyzed by scanning electron microscope (SEM). Compression, tensile and impact tests were applied for mechanical values. Nano-graphene changed the mechanical values to negative. The nano Teflon addition showed an improvement of about 35%.Öğe Effect of Rolling Deformation on Microstructure and Mechanical Properties of As-Cast and Rolled ZM21 Magnesium Alloy(Springer, 2023) Ozdemir, Umit; Koc, Erkan; Turen, Yunus; Elen, Levent; Cicek, Bunyamin; Saud, A. NajahThe current study aimed to improve the microstructure and mechanical properties of ZM21 magnesium alloy by using the rolling thermomechanical process at various temperatures (275 and 375 degrees C) and rates (40 and 60%). The rolled samples' grain size was examined, and it was found that the grain size decreased by 40% during hot deformation, reaching a grain size of 15.91 mu m. Surface roughness values were examined and found to be the lowest (parallel and perpendicular to the rolling direction) at a 60% rolling rate in 275 degrees C and the highest 40% at 375 degrees C. The highest tensile strength was obtained at a rolling rate of 60% at 375 degrees C, but it showed brittle fracture during testing. Accordingly, while the 275 degrees C rolled samples showed ductile fracture behavior, a slight reduction in mechanical properties was observed when the rolling ratio was set at 60%.Öğe Effects of alloying element and cooling rate on properties of AM60 Mg alloy(Iop Publishing Ltd, 2019) Elen, Levent; Cicek, Bunyamin; Koc, Erkan; Turen, Yunus; Sun, Yavuz; Ahlatci, HayrettinMagnesium and its alloys have become important structural materials in the last couple of decades due to their exceptional and mechanical properties. In this study, the effects of the introduction Cd, Bi, and Sn alloying elements were introduced into AM60 alloys produced from Mg-Al-Mn triple junction in order to improve the microstructural and mechanical properties. The weight percent of the alloying elements was chosen as 0.5% wt besides the introduction of the additional alloying elements, the effect of cooling rate on microstructural and mechanical properties of the alloys have been investigated. The results showed that the alloying elements introduced to AM60 resulted in an improvement in the mechanical properties of the alloys, which is attributed to the changes in the microstructure. The higher cooling rate led to the formation of the finer a-Mg master matrix which in turn enhanced the mechanical properties of the alloys. It was observed that the intermetallic phase of beta-Mg17Al12 at the grain boundaries became thinner due to the rapid cooling rate and the introduction of the alloying elements, and the continuity decreased and the intergranular distance shortened. The addition of the alloying element increased the tensile strength of the AM60 alloy from 140 MPa to 210 MPa and the elongation values increased from 5% to 22%. The effects of the alloying elements and the cooling rate on the hardness and yields properties of the samples were also studied.Öğe Experimental study of in-vitro bioanalysis and in-vivo living tissue biocompatibility of Mg-Zn alloys(Springer Heidelberg, 2023) Comba, Bahat; Cicek, Bunyamin; Comba, Arzu; Sancak, Tunahan; Akveran, Gonul Arslan; Koc, Erkan; Sun, YavuzIn this study in-vitro bioanalysis and in-vivo living tissue biocompatibility were evaluated. Pure Mg and Mg + x Zn (x = 1 and 3 wt%) alloys have been used in the study. In vitro immersion and potentiodynamic corrosion were applied to these alloys in Hank's and artificial seawater solution. The materials were kept in living tissue (gluteus-superficial) for 7 weeks in-vivo (albino-rat). After 4 and 7 week, the control and experimental groups' urine parameters, blood mineral substance levels, and radiographic image controls were evaluated. It was observed that the bio-dissolution level decreased as the Zn-ratio increased. As a result, successful results were obtained in the biocompatible and biodegradable material class of Zn-doped Mg alloys used in the study. The dissolution amount of 1.03 mm/y (for Mg + 3Zn alloy) in Hank's solution was calculated. The % vitality was determined at the level of 117%.Öğe Investigation of in-vitro biocompatibility and in-vivo biodegradability of AM series Mg alloys(Taylor & Francis Ltd, 2022) Comba, Arzu; Cicek, Bunyamin; Comba, Bahat; Sancak, Tunahan; Akveran, Gonul Arslan; Sun, Yavuz; Elen, LeventIn this study, in vitro/vivo biocompatibility experiments of Mg-Al-Mn alloy were carried out, and AM50 and AM60 alloys were used in the experiments. Immersion and potentiodynamic corrosion have been applied to these alloys in vitro. For biocompatibility, cytotoxicity test was performed. A total of 40 rats were used for the in-vivo experiment. AM series alloys were surgically placed in the femoral condyle as mini screws and monitored radiographically. AM alloys were removed together with the femur at the end of 7 weeks and further examined. After in-vivo application, the biodegradability level was successfully concluded with blood mineral analysis and urinalysis. In this study, the bioprocess of AM series Mg alloys with Al and Mn additions has been completed. As a result, the AM alloys used can be classified as biocompatible and biodegradable materials.Öğe Investigation of Intermetallic Phase Fractions and Dry-corrosive Wear Properties in Mg-Al-Si Ternary Alloy(Springer Int Publ Ag, 2024) Cicek, Bunyamin; Elen, Levent; Koc, Erkan; Saud, A. Najah; Sun, YavuzThis study produced a non-standard alloy of 85% Mg, 13.5% Al, and 1.5% Si by weight. In-depth microstructural, chemical, and morphological analyses of the secondary beta phases formed in the MgAlSi alloy were conducted. The formation processes of the intermetallic phases were also examined. Image processing was applied to the obtained microstructures using the Image-J program. The average alloy had a matrix alpha phase to secondary beta phase ratio of approximately 60/40. Furthermore, a dry and corrosive wear test were applied to the MgAlSi alloy by means of reciprocating motion. The wear rate was calculated to be at least 0.00137 mm(3)/Nm, indicating that the unique MgAlSi ternary alloy produced had very high wear resistance due to the presence of intermetallic phases.Öğe Investigation of Microstructural Evolution of Gas-assisted Metal Injection Molded and Sintered Mg-0.5Ca Alloy(Int Inst Science Sintering (I I S S), 2022) Cicek, Bunyamin; Sun, Yavuz; Turen, Yunus; Ahlatci, HayrettinIn this study, Mg-0.5Ca alloy was produced in a newly designed unit during the metal injection molding process. 40 mu m(D9)(0) Mg powder and 500nm(D90) Ca powder were used in accordance with injection molding and powder sintering rules. In the injection phase, Polyethylene-glycol (PEG) and Poly-methyl-methacrylate (PWA) and stearic acid (SA) polymers act as binders and lubricants. In the experimental phase, X-ray Diffractometer (XRD), Thermal Gravimetric Analyze (TGA), Scanning Electron Microscope (SEM) equipped with Energy Dispersive Spectroscopy Mapping (EDS and MAP), and Vickers microhardness (HV) examinations were performed. The samples produced were subjected to the sintering process at different temperatures and times. Conventional powder sinter stages point, neck, and joining structures were obtained at different temperatures and durations. As a result, it was determined that Mg-0.5Ca alloy reached a metallic form with the specified polymer structure only at 600 degrees C temperature and after 5 h sintering. Grain boundaries were formed in the sintered sample and the presence of the Mg2Ca phase was observed. The hardness of the metallic structure obtained was measured as 49.9 HV0.1 on average.Öğe Invetigations of mechanical properties after dissimilar steels post-weld of Q345B steel(Pamukkale Univ, 2020) Cicek, Bunyamin; Aydogmus, Tuna; Gundogdu Is, Emine; Sun, YavuzIn this study, it has been reported that Q345B steel combine with different steels using electric arc welding method and the mechanical properties were investigated. Produced by hot rolling processes, Q345B steel is a low-alloyed medium tensile strength and highly usable steel. The steel used contain less than 0.2% carbon and less than 0.55% silicon, chromium and nickel. In this study, Q345B steel generally used at low-pressure/temperature zones in thermal power plant (boiler wall etc.) is combined with 16Mo3 and P265GH steels. The Q345B steel is welded to make the mechanical properties easy to compare. After joining, specimens were collected from the welded areas and used in the preparation of mechanical and metallographic processes. In this process, all joints were subject to tensile, charpy, hardness and bending tests. In addition, the collection of macro images from welding were used in observation of transition zones which were operated. Electrodes with a basic character cover were used (E7018) as filler metal in the joining processes. All mechanical tests met the requirements of the relevant standards and all welds were identified as valid weld.Öğe MATERIAL PRODUCTION AND THE EFFECT OF THE SYSTEM ON BIOCOMPATIBILITY IN THE MODIFIED METAL INJECTION METHOD(Polska Akad Nauk, Polish Acad Sciences, Inst Metall & Mater Sci Pas, 2023) Cicek, Bunyamin; Sun, YavuzIn this study, the bio state of the alloy produced in the modified metal injection system was monitored after sintering. A new system operating with high gas pressure, far from the traditional injection model, has been established for material production. In this system, 316L stainless steel powders were molded using a PEG/PMMA/SA polymer recipe. During molding, approximately 60% 316L and 40% binder by volume were used. The samples obtained were sintered at different temperatures (1100-1300 degrees C) after de-binding. Density measurement (Archimedes) and hardness tests (HV1) of the samples were measured as 6.74 g/cm3 and-285 HV1, respectively. A potentiodynamic corrosion test was applied to monitor the effect of the amount of oxide in the structure of the 316L stainless steel produced. Corrosion tests were carried out in artificial body solutions. The corrosion rate was measured at the level of 17.08x10-3 mm/y. In terms of biocompatibility, a cytotoxicity test was applied to the samples and the life course of the bacteria was monitored. For the 316L alloys produced, the % vitality reached approximately 103%.Öğe Production of 316L stainless steel implant materials by powder metallurgy and investigation of their wear properties(Science Press, 2012) Kurgan, Naci; Sun, Yavuz; Cicek, Bunyamin; Ahlatci, HayrettinIn this study, the mechanical and wear properties of AISI 316L stainless steel implant materials, produced by powder metallurgy (P/M), were investigated. AISI 316L stainless steel powder was cold-pressed with 800 MPa of pressure and then sintered at 1200, 1250 and 1300A degrees C for 30 min as three sample groups. The microstructure, and mechanical and wear properties of the resulting steels were investigated. Light optical and scanning electron microscopiese were used to characterize the microstructure of the steels. Room temperature mechanical properties of the steels were determined by hardness measurements and impact tests. Wear was determined using the pin-on-disc wear test, and the results were evaluated according to weight loss. The results indicate that the sintering temperature, time and atmosphere are important parameters that affect the porous ratio of materials produced by P/M. Sintering at high temperature can eliminate small pores and make the residual pores spherical. The wear tests showed that the wear of the AISI 316L stainless steel implants changed depending on the sintering temperature and load. Spherical pores in the samples increase the wear resistance. Moreover, decreasing the porosity ratio of these materials improves all of their mechanical properties.Öğe A study on the mechanical and corrosion properties of lead added magnesium alloys(Elsevier Sci Ltd, 2012) Cicek, Bunyamin; Sun, YavuzThe purpose of this study was to investigate the effect adding Pb at different ratios had on the corrosion properties of Mg alloys. Pb, at a rate of 0.2%, 0.5%, and 1%, was added to Mg-10% Al-12Si. The microstructure characterisation, mechanical and corrosion properties of alloys, produced using a casting method was investigated. Light Optical Microscopy (LOM), X-Ray Diffraction (XRD) analyses and a Scanning Electron Microscope (SEM) were used to conduct the microstructure characterisation of investigated alloys. Corrosion tests were performed by suspending the samples of certain sizes into the 3.5% NaCl solutions measuring the weight loss, and also by potentiodynamic polarisation measurements in the same solution. According to corrosion experiment results, I-kor decreased with the addition of Pb, causing an increase in the corrosion resistance. (C) 2012 Elsevier Ltd. All rights reserved.Öğe Wear behaviours of Pb added Mg-Al-Si composites reinforced with in situ Mg2Si particles(Elsevier Sci Ltd, 2013) Cicek, Bunyamin; Ahlatci, Hayrettin; Sun, YavuzIn this study, the effect of adding Pb at different ratios on the wear resistance of Mg alloys reinforced with low density in situ Mg2Si particles has been investigated. Pb, at a rate of 0.2%, 0.5%, and 1%, was added to Mg-10% Al-12Si alloys reinforced with in situ particles, produced from the reinforcement nucleation within the matrix. The microstructure characterisation and wear properties of alloys, produced using a casting method was examined. Light Optical Microscopy (LOM), X-ray Diffraction (XRD) analyses and a Scanning Electron Microscope (SEM) were used to conduct the microstructure characterisation. A pin-on-disc type wear device, under different loads and different sliding distances, was used to conduct the dry environment wear experiments carried out for investigated alloys. Microstructure analysis concluded that Mg2Si particles formed, and that an Mg17Al12 intermetallic phase was present in the structure. The Pb added to the alloys decreased the wear resistance of the alloy. (C) 2013 Elsevier Ltd. All rights reserved.
