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Metal cutting is widely used than other production methods. Cutting forces are the leading parameters that determine process efficiency in machining operations. Cutting forces inform us about the magnitude of energy consumption during the operation. By providing certain conditions, the creation of low cutting forces reduces the costs. This is due to the accurate determination of the cutting parameters. In this study, the experiments were performed with three different cutting speeds, three different feed rates and three different cutting depths by using of AISI 1050. As a result of the experiments, the most effective cutting parameters were determined in order to keep under control of cutting forces values and get the best results. New concepts are defined by analyzing the build-up factor. These defined concepts and the relationship between machining parameters and cutting forces are expressed by mathematical models. Thanks to the mathematical models developed with this study, the force formation is explained through parameters and the appropriate processing parameters are provided for the ideal force values. [ABSTRACT FROM AUTHOR]

The aim of this study is to reveal the influence of the lead angle variation on the cutting forces in the process of face milling of compacted graphite iron with TiCN and Al2O3 coated carbide insert. To achieve this goal, 96 different milling experiments were carried out in dry and wet milling conditions with 45°, 60°, 75°, 88°'lead angles, 180, 215, 250 ve 290 m/min cutting speeds and 0,16; 0,20; 0,24 mm maximum chip thickness at the 2.5 mm constant dept of cut. The cutting forces decreased while increasing the lead angle value 45°, 60°, 75°, 88° in dry milling of compacted graphite cast iron. When cutting oil was used in the experiments, a decrease between 1,0% - 15,33% at the lead angles of 45° and 60° and an increase between 1,0% and 16,0% at the lead angles of 75° and 88° have been observed. Experimental results have been modeled with artificial neural networks and regression analysis method. A comparison of ANN model with regression model is also carried out. This study is considered to be helpful in predicting the cutting forces in milling of compacted graphite cast iron. [ABSTRACT FROM AUTHOR]

This study, investigates the positioning accuracy of the hydraulic system that is controlled by FM-357 function module used in the control of CNC machine tools. The system consists of two axes driven by two cylinders directed by proportional directional valves. The effects of feed rate, motion distance, direction and inertia load on the positioning accuracy and the determination of their optimum levels are achieved via Taguchi method. According to this, minimum positioning error is obtained in the motion distance of 5mm, in "-" direction and at the inertia load of 5kg. Lastly, the confirmation experiments showed that Taguchi method achieves the optimization of the system with sufficient accuracy. [ABSTRACT FROM AUTHOR]

This study was carried out in order to examine the influences of grinding wheel hardness on surface roughness and grinding forces during surface grinding. Grinding tests were carried out using Al2O3 grinding wheels with I, M and Q hardness grades at different table speeds and at different depth of cuts. AISI 1050 (50 HRc) and AISI 4140 steels (52 HRc) were used as the workpiece materials. In order to measure the grinding forces generated during grinding, the dynamometer previously designed and manufactured was used. This dynamometer was also connected to a personal computer to save the grinding force data. The roughness of surfaces were also measured. It is seen significant increases on surface roughness by increasing wheel hardness and grinding forces. The grinding operations carried out using grade I grinding wheels produced higher surface roughness and mean grinding force values by 53.5 % and 59.8 %, respectively, than those obtained by grade Q grinding wheel. [ABSTRACT FROM AUTHOR]

This study was carried out in order to examine the influences of grinding wheel structure on surface roughness and grinding forces during surface grinding. Grinding tests were carried out using Al2O3 grinding wheels at different table speeds and at different depth of cuts. The structures of the grinding wheels were 3, 5 and 7. AISI 1050 steel (50 HRc) was used as the workpiece material. For measurement of the grinding forces developed during grinding, a previously designed and constructed dynamometer was used. This dynamometer was also connected to a personal computer to save the grinding force data. The ground surface roughness values were also measured. Increasing grinding wheel structure resulted in significant increases in surface roughness values. However, its influence on grinding forces was marginal. The highest cutting force was obtained when grinding using grinding wheel having the lowest structure at the highest depth of cut. [ABSTRACT FROM AUTHOR]

This study has focused on chip-breaker design to break chips when machining inconel 718. For this purpose a dynamic chip breaker mechanism has been designed which can be used with positive and negative tool holders. Cutting speed, depth of cut and feed rate were selected as variables. A cemented carbide tool coated by PVD technique with two different layers (TiAlN-TiN) was selected as a cutting insert. Inconel 718 specimens were machined at f=0.10, 0.15, 0.20, 0.30 mm/dev feed rates, a=0.5, 1, 1.5, 2 mm dept of cuts and 30, 45, 60, 75 m/dak cutting speeds. Chip photographs were taken and surface roughness (Ra) values were measured. The results showed that chip breakability when machining inconel 718 was dependent on DC motor speed and chip breaker position on the cutting tool. The experimental results indicate that the designed chip breaker can break long chips when machining inconel 718 using the cutting parameters employed in this study. Also acceptable surface quality was achieved when machining Inconel 718 with dynamic chip breaker. In addition to this, depending on the cutting conditions, use of dynamic chip breaker on the surface of cutting insert exhibited cooling effect between 1 % to 44 %. [ABSTRACT FROM AUTHOR]

In this study, some certain sizes of triangular, square and circular shaped parts have been cut through CO2 laser cutting centre over a 4 and 6 mm thickness of AISI 304 stainless steel material at different cutting conditions and the effects of cutting parameters were investigated on the dimensional accuracy of the samples. As the independent variables, laser power (W), cutting feed rate (F), focus point (ON) and gas pressure (P) have been selected. By using Full Factorial Experimental Design Technique (TFT), a total of 486 experiments have been carried out on the 4 and 6 mm thick sheet materials at three different levels of the independent parameters. Using the experimental data obtained as a result of the measurements made with three-dimensional coordinate measurement machine (CMM), the second-order predictive models, including the effects of laser cutting parameters on the dimensional accuracy of the triangular, square and circular-shaped samples have been improved through the Regression Analysis. Correlation coefficients of the predictive equations developed in the 95% confidence level have been obtained over R2=0,78. In this study, furthermore, the main effect graphics showing the effects of independent variables on the dimensional accuracy have also been formed and the effects of parameters were evaluated. The most effective parameters on the dimensional accuracy of the cut parts were laser power, cutting feed rate and focus point, respectively. [ABSTRACT FROM AUTHOR]

In this study reinforced polypropylene granules have been produced by the way zinc borate are added to powder polypropylene material at the rate of 5 %, 7.5 %, 11.25 %, 16.875 % and 25.3125 %. To prevent oxidation, at the rate of 0.2 % maleic anhidrit as a antioxidant has been added to PP during the production of zinc borate reinforced polypropylene granule. After composite granule was produced, rheological properties of reinforced polypropylene have been determined by using melt flow index device (MFI). MFI, shear stress, shear rate and viscosity values have been obtained by the experiments that was carried out under four different load (298.2 kPa, 524 kPa, 689.5 kPa and 987.4 kPa) and four different temperature (190 °C, 200 °C, 210 °C and 220 °C). According to this study, it has been determined that viscosity value increased depending on zinc borate rate but viscosity decreases depending on increasing temperature and pressure. It was determined that MFI values have been increased depending on increasing temperature and pressure whereas MFI values have been decreased according to increasing zinc borate rate. In addition, it has been seen that shear rate decreases depending on increasing proportion of additive but it increases with the increase of temperature and pressure. [ABSTRACT FROM AUTHOR]