Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

Browse

Filters

2001 - 200912020 - 20242

Settings

Department: search.filters.department.Thesis (Master)--İzmir Institute of Technology, Mechanical EngineeringSubject: search.filters.subject.Aluminum alloys

Search Results

Now showing 1 - 3 of 3
  • Master Thesis
    Process improvement in the steel mold machining for aluminum alloy wheel low pressure casting industry
    (01. Izmir Institute of Technology, 2024) Tetik, Halil; Tetik, Halil; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    Alçak basınçlı döküm yöntemi ile jant üretim endüstrisinde, Dökümhane bölümleri için sürekli üretim hatları gereklidir. Gerekli üretimi elde etmek için, kalıplar dökümhanelerde hazır olmalıdır. Bu nedenle, alçak basınçlı döküm kalıplarının üretim süresi mümkün olduğunca kısa olmalıdır. Üretimi en üst düzeye çıkarmak için mevcut kapasiteyi kullanmak, daha fazla yatırım yapmaktan çok daha önemlidir. Bu, operasyonların kapsamlı bir şekilde gözden geçirilmesini, süreçler arasında görevlerin dengelenmesini ve en verimli üretimi elde etmek için operasyon sürelerinin azaltılmasını gerektirir. Zamanla daha büyük jant boyutlarına olan artan talep, alt maça için daha uzun üretim sürelerine neden olur. Daha fazla yatırım yapmaktan ziyade, mevcut kapasiteyi en üst düzeye çıkarmak çok önemlidir. Bu, operasyonların kapsamlı bir şekilde gözden geçirilmesini, süreçler arasındaki görevlerin dengelenmesini ve en verimli üretimi elde etmek için operasyon sürelerinin azaltılmasını gerektirir. Bu tezin amacı, üretimin ortasında yapılan ısıl işlem aşamasını kaldırarak toplam üretim süresini azaltmak ve süreci iyileştirmektir. Bu araştırmanın amacı, yalın üretim ve değer akış haritalama, talaşlı imalat makine parametresi optimizasyonu, takım seçimi, makine verimliliği ve üretim hattı dengelemesini kullanarak süreçleri inceleyip üretim sürecini etkileyen unsurların kapsamlı bir şekilde anlaşılmasını sağlamaktır. Değer akış haritalama kullanılarak yeni bir üretim yöntemi önerilmiş ve uygulanmıştır. Ayrıca, yeni üretim tekniğinin neden olduğu sorunların üstesinden gelmek için Taguchi yöntemi ile deney tasarımı kullanılarak işleme parametre optimizasyonu yapılmıştır. Önerilen üretim yönteminin uygulanmasıyla operasyon sayısının 12'den 8'e düşürülmesi, işçilik süresinin %2.35 azaltılması, teslim süresinin %42.65 azaltılması, kapasitenin %2.35 arttırılması, seçili makinelerde kapasite dengelenmesi, makine parametrelerinin optimizasyonu gibi birçok iyileştirme sağlanmıştır.
  • Master Thesis
    Processing and Characterization of Scandium Added A356 Cast Alloy
    (Izmir Institute of Technology, 2021) Öner, Cezmi; Kandemir, Sinan; Öner, Cezmi; Kandemir, Sinan; 01. Izmir Institute of Technology; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering
    As a result of today's rapid technological developments and the rapid consumption of reserves in the world, the search for alternative materials has started. One of the biggest examples of this is wheel alloy. Ti5B1, one of the additives of the A356 Al alloy that is generally used in automobile wheels, allows to reduce the grain size in the alloy. In the event of depletion of possible Ti5B1 resources, there will be a need to use alternative materials instead. Based on this purpose, materials that can be used instead of Ti5B1 were examined. Scandium (Sc) as a rare earth element was found to be the least studied element with A356. A number of Sc-based studies with other aluminum alloys were reported and it was decided to work with this element for A356 alloy. In the thesis, the effect of Sc adjunction on the mechanical properties of A356 aluminum alloy after the permanent die casting process was investigated. Sc added to the A356 alloy at a ratio of 0.2, 0.4 and 0.6 weight percent, respectively. Optical microscopy (OM), Scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) were used for the microstructural analyses in this study. According to the experiments and results obtained in this study, it was observed that Sc can significantly increase the mechanical properties of the A356 alloy in terms of tensile strength and hardness values. Overall, it was found that the addition of 0.2 wt.% Sc to the A356 alloy could achieve a maximum tensile strength of 258.31 MPa compared to 242.54 MPa for the reference sample without Sc. No significant improvement in tensile strength results was observed when more than 0.2 wt.% Sc was added to the alloy. As for the hardness, the sample containing 0.2 wt.% Sc reached a maximum Brinell hardness of 75.01 HB compared to 77.58 HB for the unmodified sample. As a result, the amount of porosity increased with Sc added to the alloy, and an increase in dendrite arm lengths occurred. Due to this length in the arms, a decrease in fracture toughness occurred. In addition, there was no significant improvement in hardness.
  • Master Thesis
    Investigation and Development of the Quality Control of Al-Wheel Rim Production Process
    (Izmir Institute of Technology, 2001) Çetinel, Mert; Aygün, Hacer; Aygün, Hacer; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    With the increasing use of aluminum wheels in automotive industry, the aluminum foundry industry had to focus on the quality and reliability of the products.To produce good quality aluminum cast wheels, defects must be minimized and the quality of each production step must be controlled.The main topic of this study was to investigate the production line of a big aluminum wheel foundry and improve the quality of production using quality control tools. The production parameter data and real-time x-ray inspection results have been collected. Parameters of the machines that are involved with the production and the results of testing equipment and thermal analyzer have been recorded.To obtain effective feedback during process, a proposed flow chart of the wheel production line was developed. The process parameters which have influences on the quality of wheel were determined by using Fishbone diagrams. According to the results of real-time radioscopic inspection, it was concluded that the main defects that occur on Al wheel are gas holes, porosity and shrinkage. The locations of the defects were identified with results of inspection and evaluated by using the charts. To eliminate these defects, some outstanding remedies are given in the flow chart of Al wheel production.A predicted equation between hydrogen content and density index of gas holes in molten metal was obtained by using the Least Square Method. Analysis of variance for the single factor showed that degassing time affects the hydrogen content in the molten metal. Finally, hydrogen content and the molten metal temperature relationship was investigated by a graphical method.