In the study, various vegetable oil and water mixtures were used as cutting fluid to be tested in machining. These fluids have been used as an alternative to cutting fluids made from synthetic and semi-synthetic oils, which have harmful effects on nature and humans, and their performance has been investigated. As vegetable oil, Soy, Sunflower and Canola oils were mixed with water each and separate cutting fluids were obtained. Vegetable oil and water were mixed at 7 % and 93 %, respectively, and turned into a homogeneous liquid. Dry cutting and commercial cutting fluid using for cutting was also performed in comparison turning. In the study, AISI 4140 steel was processed on a CNC turning machine using an uncoated carbide insert. In all experiments, the cutting speed was kept constant as 200 m/min, the feed rate as 0,2 mm/rev, and the depth of cut at 1 mm. Cutting fluids were used in two different ways in experiments as liquid and 4 bar pressure spraying. As a result of the experiments, tool wear and surface roughness values were studied. The best results in all processing terms have been found in experiments with pressurized spraying of a mixture of canola oil and water. The surface roughness value was measured as 1,35 μm and the tool wear value was measured as 0,13 mm. The worst values were obtained in experiments carried out under dry cutting condition. Surface roughness value was measured as 2,31 μm and tool wear value was measured as 0,24 mm.

The aim of this study was to investigate the effects of process parameters on tensile strength for PLA specimens produced by fused deposition modeling (FDM). For this purpose, two different density rates (20% and 100%), printing speeds (100 and 130 mm/s), and nozzle temperatures (180 and 220oC) with three different hatching patterns including elliptical and diagonal (Gyroid, Cross 3D ve Grid) were selected. In the study, higher tensile stress was obtained at a rate of 100%, compared to a 20% density rate. When the samples with a 20% density rate are compared among themselves, the highest tensile stress value obtained was measured as 38.76 MPa for the Grid-patterned specimen produced at a nozzle temperature of 2200C and printing speed of 100 mm/s. Statistical analysis was also done for specimens with a 20% density rate. As a result of the variance analysis (ANOVA) method, the confidence level was achieved as 96%. When comparing in terms of specific strength, it was determined that the closest pattern to the full-filled sample with a specific strength of 5,893 MPa/gr was Cross 3D-patterned sample with a value of 5.458 MPa/gr.

Çalışmada eriyik yığma modelleme (FDM) yöntemi ile 3B yazıcı kullanarak üretilen PLA numunelerin mekanik özelliklerden olan çekme dayanımına işlem parametrelerinin etkisi belirlenmesi amaçlanmıştır. Bu amaçla çalışmada işlem parametreleri olarak 2 farklı doluluk oranı (%20 ve %100), 3 farklı baskı hızı (100,150 ve 200 mm/s), 3 farklı nozul sıcaklığı (180, 205 ve 220°C) ve 3 farklı desen çeşidi (Cubic, Grid, Triangle) seçilmiştir. Çalışmada, %20 doluluk oranına göre %100 doluluk oranında daha yüksek çekme gerilmesi elde edilmiştir. %20 doluluk oranındaki numuneler kendi aralarında kıyaslandığında elde edilen en yüksek çekme gerilmesi değeri 2200C nozul sıcaklığında, 100 mm/s baskı hızında yapılan Grid desen çeşidinde 43.12 MPa olarak ölçülmüştür. %100 doluluk oranında ise en iyi sonuç 2200C de, 100 mm/s baskı hızında üretilen numunede 59.21 MPa çıkmıştır. Çalışmada %20 doluluk oranındaki numuneler için istatistik analiz yapılmıştır. Varyans analiz (ANOVA) yöntemi sonucu güven düzeyi %94,4 elde edilmiştir.

Within the scope of sustainable production, a natural liquid mixture that will act as cutting fluid is sprayed with a different system. The liquid consisting of water and soybean oil was pulverized by ultrasonic atomization method and used by spraying with 4 bar compressed air. In this study, it was aimed to investigate the effects of AISI 4140 steel on machinability in CNC lathe by using uncoated carbide insert (SECO WNMG080404-M1). Three cutting speeds (150, 200, 250 m / min), three feed rates (0.1, 0.15, 0.2 mm / rev) with four cutting fluids (1%, 5%, 10% soy oil-water mixture and commercial cutting fluid) and the comparison was made by making experiments under dry cutting conditions. In all experiments, the cutting depth was 1 mm and the cutting length was 100 mm. As a result of the experiments, cutting force, surface roughness and tool wear values were examined and contact angle measurements of cutting fluids were made. The best results in all parameters were achieved by spraying a 10% soybean oil-water mixture using an ultrasonic atomizer. The best results in all parameters were achieved by spraying a 10% soybean oil-water mixture using an ultrasonic atomizer. The worst values occurred in experiments conducted under dry cutting condition. In addition, SEM photographs were taken to observe the type of tool wear. The obtained values were analyzed with the ANOVA method and the results were evaluated with 3D surface graphics. After evaluating the analysis results, percentage impact rates, regression analysis equations and optimization values are proposed.

Additive manufacturing is a manufacturing method that includes systems that produce using many different methods. The most widely used and accessible methods of additive manufacturing can be listed as Fused Deposition Modeling (FDM), Selective Laser Sintering (SLS) and UV light assisted Stereolithography (SLA). Today, it is quite easy to produce thermoplastic products suitable for direct use in low quantities with these three methods. In addition, the production success of the parts produced in geometric difficulties also increases this demand. The most important problem is the lack of sufficient studies and information about the strength limits, surface quality and costs of the parts produced for additive manufacturing methods with such advantages. In this study, the comparison of three different production methods in terms of surface roughness, strength and cost is discussed in order to eliminate this deficiency in the literature. For this purpose, the tensile strength and surface roughness values of the samples produced using FDM, SLS and SLA methods were determined. In addition, cost analyzes were made depending on the production time of the produced samples. In the study, the lowest cost was obtained in the SLA material with a value of $ 0.19. Again, the lowest values were obtained for the samples produced from SLA material, with a production time of 17 minutes and a surface roughness of 1.96µm compared to other methods. However, when evaluated in terms of strength, the highest strength value was obtained as 57.67 N/mm2 in the FDM method.

This study aims to investigate the thermal performance of ABS, PLA, and TPU polymer composite materials produced using 3D printing technology under high-temperature conditions through simulation and experimental methods. Steady-state and transient analyses conducted using SolidWorks software evaluated the materials' temperature distribution, thermal stress, and deformation behavior. The findings indicate that temperature variations directly influence the mechanical durability of polymers and that critical stress concentrations may shorten the material's service life. Notably, TPU exhibited higher deformation levels, while PLA was found to be sensitive to pronounced temperature gradients, and ABS demonstrated a more uniform stress distribution. Optimization recommendations suggest that improvements in production parameters and design can reduce thermal stresses by 15-25%. These results provide valuable insights for developing more durable and long-lasting designs in industrial applications of polymer composites.