Papers by Keyword: Nose Radius

Abstract: Surface finish plays an important role in making quality products in the manufacturing sector. A turning experiment is conducted by cutting tool of nose radii (1 mm and 0.65 mm) to find its influence on surface roughness. Eight experiments were performed with Taguchi’s Orthogonal Array (OA) technique. The prime objective was to investigate the tool nose radius effects in the prediction of the optimum value of surface roughness. Cutting speed (V), feed (F), depth of cut (D), and tool nose radius (NR) were selected for the experimental work having two levels each. To find out the influential parameters analysis of variance (ANOVA) was carried out. Signal to noise ratio and average performance graph was analyzed to obtain optimum response values. The results concluded that the large nose radius develops a superior finish in comparison to the smaller one.

Abstract: Metal cutting is the way of processing the workpiece with tool having sharp cutting edges of different materials generating chips of different shapes and sizes. In present era of industry 4.0, metal machining should not be unrated during processing of hard grades metals and superalloys where large amount of cutting forces are generated. Also, the measurement of cutting forces provides the basic of economical machining and hence accurate evaluation in experimental and analytical manner has great importance. The traditional models of metal cutting have disagreement with experimental results due to missing of important mechanics terms. With the development of digital technology, the errors in calculation of cutting force have also been shortened due to consideration of terms absent in conventional models. In present investigation, the cutting forces have been evaluated experimentally using dynamometer and analytically with Astakhov’s methodology during turning of EN-31 steel. The results revealed that 12.9% observations have deviation more than 20%, whereas 16.67 % has zero deviation. Further, the feed rate has more influence on cutting forces as compared to speed and nose radius. In addition, the minimum quantity lubrication (MQL) of vegetable oil has lowered the cutting forces appreciably compared to dry machining.

Abstract: The article presents the problem of the minimum thickness of the machined layer which dependent on the radius of the cutting edge. The minimum thickness of the cut layer significantly affect surface roughness on the edge of a certain geometry. The paper presents useful in the research analyses and didactics Profile software for the visualization of the effects of minimum thickness of the cut layer on the surface roughness

Abstract: Hardened steel, Ni-based alloys and brittle materials are very difficult to machine using conventional cuttingmethods.A tool edge with a small nose radius can alleviate the regenerative chatter. In general, it is important for conventional cuttingto use the smallest possible tool nose radius. A sharp tool shape has an adverse effect on tool strength and the instability of machining process still occurs. A tool wear model with small nose radius proposed by past researchers is evaluated for predicting metal cutting tool wear when machining the copper. Tool temperature values are determined using finite element methods simulation. These temperatures are related to tool wear measured after metal cutting turning tests on a copper workpiece to determine tool edge geometry in low metal tool model.In this study, the effects of cutting conditions and tool edge geometry on process stability in turningare investigated through experiments and FEM simulations.

Abstract: The sheet metal bending is one of the metal forming processes with the simplest geometric interpretation and usually a 2D analysis is considered. The bend over a sheet metal blank consists of a V shape forming by using a punch, with a certain nose radius, forcing the plate against an open die, with a V section. The forming result is a part with an angle obtained between the V legs, flanges, which is known as bending angle. The operation to get the required V angle is called air bending, or free bending. The most common used machines for this forming process are press brakes, special long presses, where the tools, punch and die, are attached to. With the spread use of CNC machines, and their computer control capabilities, most of them using graphical user interface (GUI), became important to get the required shape at first trial. Beyond the required bending angle obtained with just one hit, it is also important to position the gauge system in order to get the successive flange lengths to complete the programmed shape. The main variables controlled by the CNC are the punch penetration inside the die and the position of the back gauge, which is determined by the bend allowance. However this penetration is not the only responsible for the resulting bending angle and the gauging position is not the only responsible for the flange length. Additionally, the radius inside the V shape edge, known as bending radius, influences the geometry and correspondingly the bend allowance. Some authors believe that the punch nose radius has direct influence, both in the bending angle and bend allowance. In this paper, results are presented describing the use of finite element analysis as an aid in the prediction of the inside bending radius, that influences both punch penetration for the final bending angle and the bend allowance for the final flange length. From the air bending analysis, a natural inside bending radius is presented as an important variable in these kind of processes, as well as its minor dependence on the punch nose radius.

Abstract: Chatter is the most classical problem in machining. It is prone to occur in low rigidity structures generating poor surface quality and harmful vibrations which could damage any part of the machine-tool system. In finishing operations, the effect of the tool nose radius should be taken into account in order to obtain safe and reliable cutting conditions. The present paper uses a simple SDOF model to study the stability during finishing operations.

Abstract: Based on experimental results, a predictive model with certain constraints of cutting parameters (feed rate and depth of cut) and nose radius for cutting forces is solved in precision turning 3J33 alloy. The proposed model is adequate with F-ratio test and multiple correlation coefficient of it. Regression analysis shows that depth of cut and feed rate influence the principal cutting force significantly. The goal of this study is to predict cutting forces under certain constraints of cutting parameters and nose radius.

Abstract: In precision turning, the quality of surface finish is an important requirement for machined workpiece. Thus, the choice of optimal cutting parameters is very important for controlling the required surface quality. The focus of the present study is to find a correlation between surface roughness and cutting parameters (feed rate, depth of cut) and nose radius in turning 3J33 maraging steel, and to derive mathematical models for the predicted surface roughness based on both of cutting parameters and nose radius. The experimental design is carried out using the quadratic rotary combination design. The regression analysis shows feed rate and nose radius influence surface roughness significantly. With F-ratio test the proposed model is adequate. The method could be useful in predicting roughness parameters as a function of cutting parameters and nose radius.