Mechanical Engineering / Makina Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/4129

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Author: search.filters.author.Kandemir, SinanWoS Q: search.filters.wosQuartile.Q3

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Now showing 1 - 4 of 4
  • Article
    Citation - WoS: 7
    Citation - Scopus: 7
    A Comprehensive Study on Burst Pressure Performance of Aluminum Liner for Hydrogen Storage Vessels
    (ASME, 2021) Kangal, Serkan; Sayı, Abdülmecit Harun; Ayakdaş, Ozan; Kartav, Osman; Aydın, Levent; Artem, Hatice Seçil; Aktaş, Engin; Yücetürk, Kutay; Tanoğlu, Metin; Kandemir, Sinan; Beylergil, Bertan
    This paper presents a comparative study on the burst pressure performance of aluminum (Al) liner for type-III composite overwrapped pressure vessels (COPVs). In the analysis, the vessels were loaded with increasing internal pressure up to the burst pressure level. In the analytical part of the study, the burst pressure of the cylindrical part was predicted based on the modified von Mises, Tresca, and average shear stress criterion (ASSC). In the numerical analysis, a finite element (FE) model was established in order to predict the behavior of the vessel as a function of increasing internal pressure and determine the final burst. The Al pressure vessels made of Al-6061-T6 alloy with a capacity of 5 L were designed. The manufacturing of the metallic vessels was purchased from a metal forming company. The experimental study was conducted by pressurizing the Al vessels until the burst failure occurred. The radial and axial strain behaviors were monitored at various locations on the vessels during loading. The results obtained through analytical, numerical, and experimental work were compared. The average experimental burst pressure of the vessels was found to be 279 bar. The experimental strain data were compared with the results of the FE analysis. The results indicated that the FE analysis and ASSC-based elastoplastic analytical approaches yielded the best predictions which are within 2.2% of the experimental burst failure values. It was also found that the elastic analysis underestimated the burst failure results; however, it was effective for determining the critical regions over the vessel structure. The strain behavior of the vessels obtained through experimental investigations was well correlated with those predicted through FE analysis.
  • Article
    Citation - WoS: 16
    Citation - Scopus: 17
    Investigation of the High Temperature Dry Sliding Wear Behavior of Graphene Nanoplatelets Reinforced Aluminum Matrix Composites
    (SAGE Publications, 2021) Martin, Seçkin; Kandemir, Sinan; Antonov, M.
    In this study, graphene nanoplatelets (GNPs) with a thickness of 50-100 nm have been utilized to improve the mechanical and tribological properties of A360 alloy due to their extraordinary mechanical properties and solid lubricant nature. For the investigation of tribological properties, ball-on disc tests were carried out at various temperatures including room temperature (RT), 150 °C, and 300 °C. According to the hardness and ball-on-disc test results, the nanocomposite samples reinforced with GNPs exhibited improved hardness and wear resistance. The improvement in the wear behavior of nanocomposites was referred to the temporarily formed solid lubricant film of harder GNPs during the wear, and hence coefficient of friction (COF) and volume loss were considerably reduced. Abrasive-adhesive, oxidative, and mild-to-severe were found to be main wear mechanisms at RT, 150 °C, and 300 °C, respectively. Overall, the results show that the nanocomposites fabricated by casting method combined with mechanical stirring and ultrasonication have promising wear performance, especially at elevated temperatures. This may suggest that these developed materials could be potential candidates to be used in the engineering applications requiring high temperature wear performance. © The Author(s) 2020.
  • Article
    Citation - WoS: 35
    Citation - Scopus: 39
    Development of Graphene Nanoplatelet-Reinforced Az91 Magnesium Alloy by Solidification Processing
    (Springer Verlag, 2018) Kandemir, Sinan
    It is a challenging task to effectively incorporate graphene nanoplatelets (GNPs) which have recently emerged as potential reinforcement for strengthening metals into magnesium-based matrices by conventional solidification processes due to their large surface areas and poor wettability. A solidification processing which combines mechanical stirring and ultrasonic dispersion of reinforcements in liquid matrix was employed to develop AZ91 magnesium alloy matrix composites reinforced with 0.25 and 0.5 wt.% GNPs. The microstructural studies conducted with scanning and transmission electron microscopes revealed that fairly uniform distribution and dispersion of GNPs through the matrix were achieved due to effective combination of mechanical and ultrasonic stirring. The GNPs embedded into the magnesium matrix led to significant enhancement in the hardness, tensile strength and ductility of the composites compared to those of unreinforced AZ91 alloy. The strength enhancement was predominantly attributed to the grain refinement by the GNP addition and dislocation generation strengthening due to the coefficient of thermal expansion mismatch between the matrix and reinforcement. The improved ductility was attributed to the refinement of β eutectics by transforming from lamellar to the divorced eutectics due to the GNP additions. In addition, the strengthening efficiency of the composite with 0.25 wt.% GNP was found to be higher than those of the composite with 0.5 wt.% GNP as the agglomeration tendency of GNPs is increased with increasing GNP content. These results were compared with those of the GNP-reinforced magnesium composites reported in the literature, indicating the potential of the process introduced in this study in terms of fabricating light and high-performance metal matrix composites.
  • Article
    Citation - WoS: 14
    Citation - Scopus: 16
    Microstructure and Mechanical Properties of A357/Sic Nanocomposites Fabricated by Ultrasonic Cavitation-Based Dispersion of Ball-Milled Nanoparticles
    (SAGE Publications Inc., 2017) Kandemir, Sinan
    In this work, A357/0.5 wt.% SiC nanocomposites were fabricated with a combination of ultrasonic processing and a nanoparticle feeding mechanism that involves the introduction of a closed end aluminium tube filled with the ball-milled SiC nanoparticles (20-30 nm) and aluminium powders (<75 μm) into the melt for complete deagglomeration and uniform dispersion of nanoparticles through the matrix. The microstructural and mechanical properties of the fabricated nanocomposites were investigated. The microstructural studies conducted with optical and advanced electron microscopes indicate that relatively effective deagglomeration and uniform dispersion of SiC nanoparticles into the molten alloy were achieved. The hardness and tensile properties of the nanocomposites were notably improved compared to those of the ultrasonically processed A357 alloy without reinforcement, showing the strengthening potency of nanoparticles and the good bonding obtained at the particle-reinforcement interface.