Wire Arc Additive Manufacturing (WAAM) is a relatively new manufacturing method. It is a novel technique to build net-shaped or near-net-shaped metal components in a layer-by-layer manner via applying metal wire and selection of a heat source such as laser beam, electron beam, or electric arc. WAAM process is preferable as an alternative to traditional manufacturing methods especially for complex featured and large scale solid parts manufacturing and it is particularly used for aerospace structural components, manufacturing and repairing of dies/molds. TIG welding-based WAAM method is implemented by depositing continuous wire melted via heat. In this study, the overhang (self-supporting) angle in TIG welding-based wire arc additive manufacturing process is investigated. The overhang angles are the angles at which a 3D printer can build tapered (overhang) surfaces without the need to supporting material below the printing layer. The material, bead height, TIG weld parameters and the environment temperature (cooling rate of printed layer) are the parameters which affect the overhang angle. The results show that the maximum overhang angle is also dependent on the temperature of the previous layer. For the selected set of process parameters, the maximum overhang angle is found as 28o, if the temperature of the previous layer is cooled to 150oC before the subsequent layer is deposited.

Reverse engineering (RE) aims at the reproduction of products following a detailed examination of their construction or composition. Nowadays, industrial applications of RE were boosted by combining it with additive manufacturing. Printing of reverse-engineered elements has become an option particularly when spare parts are needed. In this paper, a case study was presented that explains how such an approach can be implemented in the case of products with asymmetric mechanical properties and using replacement materials. In this case study, a reverse engineering application was conducted on a textile machine spare part. To this end, the nearest material was selected to the actual material selection and some mechanical tests were made to validate it. Next, a replacement part was designed by following the asymmetric push-in pull-out characteristic. Finally, the finite element analysis with Additive Manufacturing was combined and validated experimentally.

Hybrid Additive Manufacturing (Hybrid-AM) describes multi-operational or multi-functional additive manufacturing systems. In industry, the increasing tendency in applications of Hybrid-AM brings up the challenge of improving novel methods for the manufacturing of new or hybrid parts. Hybrid AM can produce fully functional assemblies without any assembly operation. In this study, the hybrid additive manufacturing system means that an object is to be designed partly made from prefabricated or off-theshelf parts and added by the wire arc additive manufacturing (WAAM) process. For this purpose, a prototype Hybrid-AM system using the pulsed TIG-Wire-Arc technique was designed and constructed. The constructed The shaped metal deposition (SMD) system has three drivers on the x, y, and z-axes and an additional rotary driver (fourth axis). Using the Hybrid-AM machine the wire form material can be deposited on an existing primitive profile i.e., a rod, pipe, a profile, or any 3D surfaces with reducing production time. In this way, spiral-shaped features or twisted blade shapes can be added to cylindrical parts. In this study, a stainless-steel propeller blade was deposited on a pipe by using the developed prototype Hybrid AM machine. A non-planar toolpath was used to deposition the subsequent layers and the surface of the propeller blade was finished using 4-axis CNC machining.

Asimetrik dişliler özellikle tek yönlü güç ve hareket iletiminin olduğu uygulamalarda simetrik dişlilere göre daha üstün performansları nedeniyle tercih edilmektedirler. Asimetrik dişlilerin imalatında, hassas dövmecilik teknolojisinin kullanılması ile profilden kaynaklanan imalat sınırlandırmaların ortadan kaldırılması ve yüksek mukavemete sahip dişlilerin verimli bir şekilde üretilmesi mümkün olacaktır. Bu çalışmada, asimetrik düz dişlilerin hassas dövme işleminde, üst sınır enerji metodu (ÜSEM) kullanılarak dövme yükü ve malzeme akışının belirlenmesi için bir analiz sunulmuştur. Bu analizde, asimetrik dişin süren ve sürülen tarafları 12 şekil değiştirme bölgesine ayrılmıştır. Yapılan analizde, iş parçası malzemesinin isotropik ve homojen olduğu, dövme sırasında pekleşmediği, simetri ekseni boyunca malzeme geçişi olmadığı ve simetri ekseni üzerinde malzeme akış hızlarının eşit olduğunu varsayılmıştır. Bölgesel malzeme akış hızlarının hesaplanması ve enerji denklemlerinin çözümü, Python programlama dilinde geliştirilen bir yazılımla gerçekleştirilmiş ve interaktif bir kullanıcı arayüzü sunulmuştur. Prototip bir asimetrik dişli için dövme deneyleri yapılarak elde edilen sonuçlar üst sınır enerji analizi (ÜSEA ) sonuçlarıyla karşılaştırılmıştır. ÜSEA ile elde edilen dövme yükü değişimi ve malzeme akışı, deneysel sonuçlarla benzer olup maksimum dövme yükü göre %10’un altında bir sapma göstermiştir. Geliştirilen yazılım ile dövme yükü kısa bir süre içerisinde hesaplanabilmektedir. Hesaplanan maksimum dövme yükünün deneysel olarak belirlenenden daha yüksek olması, üst sınır enerji metodunun özelliğinden kaynaklanmakta olup, kalıp tasarımı ve pres kapasitesinin belirlenmesinde emniyetli bölgede kalmak için uygundur.