Papers by Keyword: Coated Carbide Insert

Abstract: The aim of this research is to investigate the influence of lead angle, cutting speed and the maximum chip thickness on tool wear in face milling process of compacted graphite iron. Tool failure modes and wear mechanisms for all cutting tools were examined in respect of various cutting parameters and were evaluated on the base of the flank wear. SEM analyses of the cutting inserts were performed and experimental results have been modelled with artificial neural networks (ANN) and regression analysis. A comparison of ANN model with regression model is also carried out. Predictive ANN model is found to be capable of better predictions for flank wear within the range used in network training. The R2 values for testing data were calculated as 0.992 for ANN and 0.998 for regression analysis, respectively. This study is considered to be helpful in predicting the wear mechanism of the coated carbide insert in the machining of compacted graphite iron.

Abstract: An experimental investigation was conducted to analyze the machined surface in high-speed dry milling of Ti-6Al-4V alloy using coated carbide inserts, with white light interferometer, scanning electron microscope (SEM), and X-ray diffraction (XRD) employed. The effect of cutting force and the workpiece temperature rise on the machined surface under different cutting speeds was discussed. As cutting speed increases above 150 m/min, the mean cutting forces decrease remarkably, but the corresponding higher temperature will be harmful to the machined surface. A deformed layer is detected by SEM with grains orientation along the feed direction from the sub-surface microstructure. The 3D surface topography and XRD patterns confirm the intense deformation of the machined surface and show a crystallographic texture modification. However, no phase transformation was observed. The β phases seem to experience more deformation and volume shrinkage in the near surface with the increase in cutting speed. And the observed variations of the machined surface with the cutting speed should be attributed to the elevated workpiece temperature rise under dry milling.

Abstract: This paper proposes a multi-criteria optimization technique using the mathematical models developed by the response surface methodology (RSM) for the target responses combined with desirability indices for the determining the optimum cutting parameters in end milling of AISI D2 hardened steels. Different responses may require different targets either being maximized or minimized. Simultaneous achievement of the optimized (maximum or minimum) values of all the responses is very unlikely. In machining operations tool life and volume metal removed are targeted to be maximized whereas the machined surface roughness need to be at minimum level. Models showing the combined effect of the three control factors such as cutting speed, feed, and depth of cut are developed. However, a particular combination of parameter levels appears to be optimum for a particular response but not for all. Thus adoption of the method of consecutive searches with higher desirability values is found to be appropriate. In this study the desirability index reaches to a maximum value of 0.889 after five consecutive solution searching. At this stage, the optimum values of machining parameters - cutting speed, depth of cut and feed were determined as 44.27 m/min, 0.61 mm, 0.065 mm/tooth respectively. Under this set condition of machining operations a surface roughness of 0.348 μm and volume material removal of 7.45 cm3 were the best results compared to the rest four set conditions. However, the tool life would be required to compromise slightly from the optimum value.

Abstract: The great advancement in the development of carbide cutting tool with super-hard coating layers taken place in recent few decades, can improve the performance of cutting tool and machinability of titanium alloy. The turning parameters evaluated are cutting speed (55, 75, 95 m/min), feed rate (0.15, 0.25, 0.35 mm/rev), depth of cut (0.10, 0.15, 0.20 mm) and tool grade of PVD carbide tool. The results that tool life shows patterns of rapidly increase at the initial stage and gradually increased at the second stage and extremely increased at the final stage. The trend lines of surface roughness have are the surface roughness value is high at first machining after that regularly decreases. Work hardening of the deformed layer beneath machined surface caused higher hardness than the average hardness of the base material. However, the softening effect also occurred below the machined surface. Segmentation or serration at the chip edge was caused by high strain and pressure during machining.

Abstract: In this paper, some experiments were conducted to investigate tool wear when end-milling Inconel 718 with the TiAlN-TiN PVD coated carbide inserts. The worn tools were examined thoroughly under scanning electron microscope (SEM) with Energy Dispersive X-ray Spectroscopy and 3D digital microscope to expatiate tool wear morphologies and relevant mechanisms. The flank wear was uniformity in finishing milling process, and the average flank wear were selected as the criterion to study the effects of cutting parameters (cutting speed, feed per tooth, radial depth of cut, and axial depth of cut) on tool wear. Finally, the optimal combination of the cutting parameters for the desired tool life is obtained.