Papers by Keyword: Turning

Abstract: The paper presents the results of turning tests with PCD and CBN tools of super hard materials such as sintered carbides WC-Co with different Co content in the material structure. In studies, the attention has been focused on the main cutting force component F_c and the surface roughness parameter Ra values, depending on the cutting data (v_c, f, a_p).

Abstract: The paper presents an analysis of the selection of the regression function in the optimization of steel turning using Taguchi method. The study attempts to investigate cutting force and temperature during turning of steel. Taguchi L16 (4) 2 orthogonal array has been applied for experimental design. S/N ratio and ANOVA analyses were performed to identify significant parameters influencing cutting force and temperature. Mathematical models for both response parameters i.e. cutting force and temperature roughness were obtained through regression analysis. The confirmation experiments carried out at optimal combination of parameters given by Taguchi’s analysis. The optimal solution provided by desirability function optimization was compared with the optimal setting of parameters given by Taguchi analysis. The optimization results provided by both techniques are in close proximity.

Abstract: As a measure to perform a burnishing process easily on an NC lathe, the authors propose a new method using a flank face positioned in a few millimeters lower part of the nose cutting edge of a tool. In the experiment, giving a fixed depth of burnishing (t=1, 2 and 4μm/pass), the carbon steel workpiece (S45C) of φ30mm which had been turned at V=200m/min and f=0.15mm/rev was burnished by predefined number of times. As a result, the surface roughness improved in nearly proportion to the total depth of burnishing and the roughness value of Rz≈10μm measured after turning could be improved to Rz≈2.5μm. Utilizing the feed control with an accuracy level of micron meters of the NC lathe, an attempt to control the dimensional accuracy of the workpiece diameter in the order of micron meters was also made. As a result, the workpiece radius came down constantly by 0.6~0.8 times in proportion to the tool depth of burnishing (t=1μm/pass), which reveals that the dimensional accuracy of the workpiece diameter could be controlled by the proposed burnishing process utilizing a fixed depth of burnishing system. Using the same burnishing process, circularity of the workpiece Δr could be improved to Δr≈2μm from Δr≈4μm measured after turning.

Abstract: The purpose of this research is to find the effects of cutting speed on the performance of the ZTA ceramic cutting tool. Three types of ZTA tools used in this study which are ZTA-MgO(micro), ZTA-MgO(nano) and ZTA-MgO-CeO₂. Each of them were fabricated by wet mixing the materials, then dried at 100°C before crushed into powder. The powder was pressed into rhombic shape and sintered at 1600°C at 4 hours soaking time to yield dense body. To study the effect of the cutting speed on fabricated tool, machining was performed on the stainless steel 316L at 1500 to 2000 rpm cutting speed. Surface roughness of workpiece was measured and the tool wears were analysed by using optical microscope and Matlab programming where two types of wear measured i.e. nose wear and crater wear. Result shows that by increasing the cutting speed, the nose wear and crater wear increased due to high abrasion. However, surface roughness decreased due to temperature rise causing easier chip formation leaving a good quality surface although the tool wear is increased.

Abstract: In the field of machining difficult-to-cut materials like titanium or nickel-based alloys, the use of a high-pressure lubricoolant supply may result in a significant increase of productivity and process stability. Due to enhanced cooling and lubrication of the cutting zone and thus reduced thermal tool load, tool wear can be decreased which allows higher applicable cutting speeds. Furthermore, the process stability can be increased as a result of effective chip breaking and chip evacuation. Since energy efficiency is very crucial, pressure and flow rate have to be adjusted carefully and in accordance with the cutting parameters to guarantee best results with less energy. For this purpose, experimental investigations were carried out under variation of the flow rate in order to find the minimum required value for a certain machining task with the overall aim to prevent waste of the media used. To maximize the positive effect of high pressure lubricoolant supply strategy on productivity and process stability, specially designed lubricoolant jet guidance geometry on the rake face was also investigated and compared to conventional turning inserts. To study the effect of high-pressure lubricoolant supply on tool temperature, reference tests also carried out using conventional overflood cooling (CoC). The results suggest that the tool temperature can be significantly decreased compared to CoC by applying the high pressure lubricoolant supply and using specially designed jet guidance geometry in turning the investigated aerospace materials TiAl6V4 and Inconel 718.

Abstract: Machining technology has undergone an extensive evolution throughout the last decades in its capability to machine hard-to-cut material. This paper will discuss about the next generation insert with cooling feature coupled with forced coolant in machining Inconel 718. The geometry of the insert was changed in a way which has enlarged the surface area approximately 12% compared to regular insert named as nusselt insert. The idea applied in “nusselt insert” was the relation of increase in surface area to heat dissipation. Forced coolant application has become a way to improve existing metal cutting concepts and improve their current material removal rates without any need for a reengineered machining process.Experiments conducted on the inserts is that the first experiment of its kind in machining technology together with forced coolant and tested in four different inserts. The primary focus of the work was the investigation of the relation between the heat dissipation with an increase in surface area/mass ratio in the cutting interface based on its influence on tool wear. The experimental results showed the nusselt insert have better ability for heat dissipation which has led to significant reduce in tool wear and successfully facing Inconel 718 at v_c 105 m/min, f 0.3 mm/rev and a_p 1 mm where the regular insert had a catastrophic failure at v_c 90 m/min, f 0.1 mm/rev and a_p 1 mm. Nusselt insert has shown to increase MRR significantly compared to regular insert.

Abstract: Recently, Firefly Algorithm (FA) has become an important technique to solve optimization problems. Various FA variants have been developed to suit various applications. In this paper, FA is used to optimize machining parameters such as % Volume fraction of SiC (V), cutting speed (S), feed rate (F), depth of cut (D) and machining time (T). The optimal machining cutting parameters estimated by FA that lead to a minimum surface roughness are validated using ANOVA test.

Abstract: In metal cutting, increasing cutting spped and feed achieve higher productivity, but it will affect dimensional accuracy and surface integrity of the work surface, wear resistance and life of tool. Cutting fluids when appropriately chosen and applied will minimize these problems. This work deals with the optimization of process parameters in turning of EN24 and SS316L Steels with different cutting fluids with different cutting inserts under different machining conditions using Taguchi’s Robust Design Methodology. The control factors selected are machining environment, cutting speed, feed, depth of cut, work piece material and type of tool. Investigations are carried out on conventional lathe using the prefixed cutting conditions. Tool Wear and Surface Roughness are measured and anlysed using ANOVA and appropriate conclusions are derived.

Abstract: This paper is to evaluate the cutting force and surface roughness in turning of Glass fiber reinforced plastics (E-glass fiber) using coated carbide insert. The comparison of the results with uncoated carbide inserts. The carbide insert is coated by multilayer chemical vapour deposition process, the coating elements are TiN/Al2O3/TiCN. The experiment is carried out in the conventional lathe machine under dry condition by varying the three cutting parameter such as speed, feed and depth of cut. The cutting force is measured using a lathe tool dynamometer and surface roughness are measured by using surf tester.The result of the experiment shows the effect of machining parameter on cutting force and surface roughness. The results have confirmed that the coated carbide insert has better results than uncoated and tool life is increased.

Abstract: In this present work, influence of cutting parameters on feed force is studied and optimized using Taguchi approach. AISI 1018 steel alloy is selected and machined using tungsten carbide tool. Eighty-One specimens were thus turned and cutting force was measured using lathe tool dynamometer. L₂₇ orthogonal array in Taguchi approach selected for optimization. From ANOVA, the results showed that out of the parameters selected feed rate has major effect on feed force. In addition, the combination of cutting speed and feed rate has major effect on feed force