This study investigated the effects of FDM (Fused Deposition Modeling) process parameters on mechanical properties (tensile strength, elongation, and impact strength) of 3D (three-dimensional) printed PA12 (Polyamide12) samples using Taguchi method. In the experimental design (L8), four different layer thickness (0.1, 0.15, 0.2, 0.25 mm), extruder temperature (250 and 260°C), filling structure (Rectilinear and Full Honeycomb), and occupancy rate (25 and 50%) were determined. The tensile and impact strength test samples were printed with the FDM method. Tensile and impact strength of the test samples were carried out according to ISO 527 and ISO 180 test standards. The findings obtained from tests were analyzed and compared. As a result, the layer thickness is most effective factor for enhance the mechanical properties instead extruder temperature, occupancy rate, and filling structure. The optimum tensile strength of determined for process parameters (layer thickness, occupancy rates, filling structures and extruder temperature) were 0.25 mm, 50%, Rectilinear, and 250°C, respectively. The optimum impact strength of determined for process parameters (layer thickness, occupancy rates, extruder temperature, and filling structures) were 0.25 mm, 50%, 250°C, and Rectilinear, respectively. PA12 filament material can be used to printing for sleeve bearing due to their mechanical properties. It can be used in the production of many machine parts and components due to its tensile strength, impact strength resistance and damping properties.

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Additive Manufacturing (AM), widely known as three-dimensional (3D) printing, is the process that a product is fabricated layer by layer in Cartesian coordinate system. Fused Deposition Modelling (FDM) is the most used AM process for functional rapid prototyping and products reduces the time and material involved in manufacturing. The purpose of this study is to investigate the effects of 3D printer system vibrations on the surface roughness of fabricated products. Polyethyletherphthalate Glycol (PET-G) is used as material for fabrication. Six different filling structures -Rectilinear, Grid, Triangular, Wiggle, Fast Honeycomb, and Full Honeycomb -were used and for each structure two different top -two and three -layers implemented. A total of 12 samples specimens were fabricated. The results showed that using Full Honeycomb filling structure with three top layers is more suitable for surface roughness compare to the others filling structure used. It can be concluded that the vibration of 3D printer system considering type of filling structure and number of top layers have a significant effect on surface quality of product. ÖZETYaygın olarak üç boyutlu (3D) baskı olarak bilinen Eklemeli Üretim (Additive Manufacturing -AM), bir ürünün Kartezyen koordinat sisteminde katmanla üretildiği süreçtir. Erişim Birikim Modelleme (Fused Deposition Modeling -FDM), fonksiyonel hızlı prototipleme ve ürün için en çok kullanılan AM sürecidir, üretimle ilgili zamanı ve malzemeyi azaltır. Bu çalışmanın amacı, 3D yazıcı sistem titreşimlerinin, imal edilen ürünlerin yüzey pürüzlülüğü üzerindeki etkilerini araştırmaktır. Üretim için malzeme olarak Polietileterftalat Glikol (PET-G) kullanılmıştır. Altı farklı dolgu şekli -Rectilinear, Grid, Triangular, Wiggle, Fast Honeycomb ve Full Honeycomb -kullanılmış ve her yapı için iki farklı üst katmaniki ve üç katmanuygulanarak toplam 12 test numunesi basılmıştır. Basılan ürünlerin yüzey pürüzlülüğü ölçümleri yapılarak elde edilen veriler üzerinden karşılaştırma yapılmış ve sonuçlar analiz edilmiştir. Sonuçlar, üç üst katmanlı ızgara (Grid) doldurma yapısının kullanılması, yüzey pürüzlülüğü için diğer doldurma yapılarına kıyasla daha uygun olduğunu göstermiştir. Dolgu Düzce Üniversitesi Bilim ve Teknoloji Dergisi, 7 (2019) 147-157 şekli türüne ve üst katmanların sayısına bağlı olarak 3D yazıcı sisteminin titreşiminin ürünün yüzey kalitesi üzerinde önemli bir etkisi olduğu görülmüştür.

In addition to traditional manufacturing methods, Additive Manufacturing (AM) has become a widespread production technique used in the industry. The Fused Deposition Modeling (FDM) method is one of the most known and widely used additive manufacturing techniques. Due to the fact that polymer-based materials used as depositing materials by the FDM method in printing of parts have insufficient mechanical properties, the technique generally has limited application areas such as model making and prototyping. With the development of polymer-based materials with improved mechanical properties, this technique can be preferred in wider application areas. In this context, analysis of the mechanical properties of the products has an important role in the production method with FDM. This study investigated the mechanical properties of the products obtained by metal/polymer composite filament production and FDM method in detail. It was reviewed current literature on the production of metal/polymer composite filaments with better mechanical properties than filaments compatible with three-dimensional (3D) printers. As a result, it was found that by adding reinforcements of composites in various proportions, products with high mechanical properties can be obtained. Thus, it was predicted that the composite products obtained in this way can be used in wider application areas.

This study investigated the effects of Deep Cryogenic Treatment (DCT) on machinability, hardness, and microstructure in dry turning process of AISI 4140 (48-51 HRc) tempered steels with ceramic cutting tools on the surface roughness (Ra). DCT process of steels has shown significant improvement in their mechanical properties. In this context, experiments were made with Taguchi L16 method and optimum values were determined. Three different values for each control factors as: different heat treated samples, cutting speeds (160, 200, 240, 280 m/min), feed rates (0.08, 0.12, 0.16, 0.20 mm/rev) were selected. As a result, the lowest Ra value was found to be 0.159 µm for the DCTT36 sample at a cutting speed of 240 m/min, a feed rate of 0.08 mm/rev. The optimum Ra value was the lowest for the DCTT36 sample compared to the other samples as 0.206 µm. The hardness values of the micro and macro were highest for the DCTT36 sample. Microstructural point of view Scanning Electron Microscopy (SEM) point of view, the DCCT36 sample showed that best results owing to its homogeneity. It was concluded that lower Ra values can be obtained with ceramic cutting tool in dry turning experiments according to the studies in the literature review. It is thought to be preferred as an alternative to cylindrical grinding process due to lower cost.