Effect of Tool Condition on Cutting Mechanism in Micromilling

2019 ◽  
Author(s):  
Alwin Varghese ◽  
Vinay Kulkarni ◽  
Suhas S. Joshi
Keyword(s):  
Surface Finish ◽  
Micro Milling ◽  
Machining Parameters ◽  
Cutting Mechanism ◽  
Workpiece Material ◽  
Tool Condition ◽  
Force Signal ◽  
Surface Profiles ◽  
Cutting Mechanisms ◽  
Rapid Tool

Abstract Cutting mechanism in micromilling is governed by the tool condition along with the machining parameters and workpiece material properties. A rapid tool wear in micromilling often deteriorates the surface quality, which could be due to the occurrence of plowing. The effects of tool condition on the transition in cutting mechanisms from shearing to plowing have not been adequately addressed in micro milling. In this work, we attempt to correlate cutting mechanism with tool conditions, so that their influence on force and surface profiles are investigated. Micro milling experiments are performed to investigate these correlations. A fluctuation parameter has been defined to quantify the fluctuation in force signal. It is evident that as the feed varies from 0.2 μm/teeth to 5 μm/teeth, the fluctuation reduces and similar fluctuations are reflected on the generated surface also. The surfaces corresponding to lower force fluctuations has an Ra value less than 350 nm. As cutting edge radius increases, surface finish decreases. However, with chipping, new sharper cutting edges are formed which may improve the surface finish locally but contribute to the overall variation in the surface profiles.

scholarly journals The Experimental Investigation of Surface Roughness After Dry Turning of Steel S235

2019 ◽  
Vol 26 (4) ◽  
pp. 179-184
Author(s):  
Justyna Molenda
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Cutting Speed ◽  
Scientific Work ◽  
Machining Process ◽  
Cutting Fluid ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Workpiece Material ◽  
Important Indicator

AbstractNowadays lot of scientific work inspired by industry companies was done with the aim to avoid the use of cutting fluids in machining operations. The reasons were ecological and human health problems caused by the cutting fluid. The most logical solution, which can be taken to eliminate all of the problems associated with the use of cooling lubricant, is dry machining. In most cases, however, a machining operation without lubricant finds acceptance only when it is possible to guarantee that the part quality and machining times achieved in wet machining are equalled or surpassed. Surface finish has become an important indicator of quality and precision in manufacturing processes and it is considered as one of the most important parameter in industry. Today the quality of surface finish is a significant requirement for many workpieces. Thus, the choice of optimized cutting parameters is very important for controlling the required surface quality. In the present study, the influence of different machining parameters on surface roughness has been analysed. Experiments were conducted for turning, as it is the most frequently used machining process in machine industry. All these parameters have been studied in terms of depth of cut (ap), feed rate (f) and cutting speed (vc). As workpiece, material steel S235 has been selected. This work presents results of research done during turning realised on conventional lathe CDS 6250 BX-1000 with severe parameters. These demonstrate the necessity of further, more detailed research on turning process results.

New Machining Method for Nickel Based Thermal Sprays

1994 ◽  
Author(s):  
Joel H. Cohen ◽  
James H. Dailey
Keyword(s):  
Tool Wear ◽  
Surface Finish ◽  
Inconel 718 ◽  
Cubic Boron Nitride ◽  
Cutting Tools ◽  
Machining Parameters ◽  
Air Plasma ◽  
Thermal Sprays ◽  
Part Surface ◽  
Rapid Tool

The routine overhaul and repair of gas turbine components requires dimensional restoration of many components. This process is usually accomplished by using various thermal sprays to build up the worn part surface and then machining or grinding the thermal sprays to correct part tolerances and dimensions. These surfaces usually contain numerous holes that generate heavily interrupted surfaces to be machined. The combination of interrupted cuts and a very wear resistant thermal spray causes rapid tool wear on conventional carbide cutting tools. This rapid tool wear also produces poor surface finish, part taper, chipping around the hole edges, and increased tool pressure that could result in lifting or peeling of the sprayed material from the parent metal. This paper summarizes the results of machining nickel based thermal sprays with polycrystalline cubic boron nitride (PCBN) cutting tools. The tests have shown a minimum 2–5x improvement in surface finish, dimensional control, part taper and up to 10x increase in productivity. The PCBN tools also generated lower cutting forces resulting in reduced stress and higher bond strengths in the part. This paper presents the data collected and the recommended machining parameters developed under controlled conditions for machining air plasma sprayed Metco 443, Metco 450, Inconel 718, two wire arc applied TAFA 75B, TAFA 73MXC, and high velocity oxygen fuel applied Inconel 718.

Machining Parameters Mapping’s of Inconel 718 and Aluminum Alloy 1100 in Micro-Milling Process

2020 ◽  
Vol 846 ◽  
pp. 99-104
Author(s):  
Gandjar Kiswanto ◽  
Maulana Azmi ◽  
Adrian Mandala ◽  
Dede Lia Zariatin ◽  
Tae Jo Ko
Keyword(s):  
Aluminum Alloy ◽  
Inconel 718 ◽  
Cutting Tool ◽  
Milling Process ◽  
Machining Process ◽  
Micro Milling ◽  
Depth Of Cut ◽  
Manufacturing Cost ◽  
Machining Parameters ◽  
Workpiece Material

The development of micro-products in industry, like aviation, medical equipment, electronics, etc, has been increasing lately. The need for scaling down of product has been increasing to make the product simpler and complex. Micro-milling has capabilities in producing complex parts. In this study, mapping and comparing the result of the machining process of Inconel 718 and Aluminum Alloy 1100 was employed. In this experiment, Inconel 718 was used as workpiece material and the result of Aluminum Alloy taken from recent studies. Then, A cutting tool with a diameter 1 mm carbide coating TiAlN was used in this experiment. The machining process was performed with three varieties of spindle speed and feed rate with a constant depth of cut. After the machining is done, the mapping of the result surface roughness of Inconel 718 and AA1100 performed. It was found that Inconel 718 has poor machinability compared with AA 1100. Inconel 718 also has a high manufacturing cost compared to AA 1100 because the cutting tool was easy to wear.

Micro-Ball Endmilling of Tungsten Carbide for Micro-Molding and Prototyping Applications

2012 ◽  
Vol 516 ◽  
pp. 591-594 ◽  
Author(s):  
Muhammad Arif ◽  
Mustafizur Rahman ◽  
Yoke San Wong ◽  
Kui Liu
Keyword(s):  
Tungsten Carbide ◽  
Inclination Angle ◽  
Surface Finish ◽  
End Milling ◽  
Depth Of Cut ◽  
Work Piece ◽  
Machining Parameters ◽  
Cutting Mechanism ◽  
High Quality ◽  
Ball End Milling

This paper presents micro-ball end milling of tungsten carbide using a CBN cutter to investigate its capability for machining slots for micro-moulds. Crack-free slots were machined at different axial depths of cut by inclining the work piece surface at different angles to the spindle axes to study the influence of these machining parameters on the cutting mechanism and surface finish. The experimental results show that up to 150 µm deep slots can be finished efficiently on tungsten carbide work pieces without leaving any fracture marks. It was identified that the chip disposal ability of micro-ball end milling reduced with increase in axial depth of cut. The cutting action was more efficient in up milling cuts compared to that in down milling when machining a slot. The inclination of the work piece proved propitious for machining slots with high-quality finish on tungsten carbide work pieces and a larger inclination angle also facilitated chip disposal.

Effect of machining parameters and vibration on polymethylmethacrylate curved surface in single-point diamond turning

2020 ◽  
pp. 251659842094172
Author(s):  
Kuldeep A. Mahajan ◽  
Raju Pawade
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Feed Rate ◽  
Single Point ◽  
Optical Devices ◽  
Diamond Turning ◽  
Curved Surface ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Workpiece Material

Single-point diamond turning (SPDT) is an emerging process for achieving nanometric surface finish, required in various optical devices made from metals like aluminum, copper, and nonmetals like polymers. The optical devices are manufactured in different shapes and profiles, preferably flat and curved surfaces. During the manufacturing of optical devices, controllable and noncontrollable parameters affect the desired surface finish. In this article, controllable machining parameters such as the incremental distance of X slide, feed rate, spindle speed, and depth of cut are selected to study their effect on surface finish and vibration generation of the curved surface. The chosen workpiece material is polymethylmethacrylate (PMMA). Design of experiment (DoE) is used to find out the optimum parameters of surface finish and infeed vibration responses. According to the Taguchi and analysis of Variance (ANOVA) analysis, the feed rate is the most influencing parameter for surface roughness, and incremental distance is for infeed vibration. A confirmation test is carried out to verify the experimental responses with a mathematical regression model, and it shows a close difference within 2.7 percent. Further, minimum surface roughness is perceived as 12.4 nm, corresponding to an infeed vibration amplitude of 4.9 µm/s2, which is signified at a lower frequency.

Chatter Stability in Micro Milling Processes Considering Ploughing and Process Damping Effects

2009 ◽  
Author(s):  
Ramin Rahnama ◽  
Mozhdeh Sajjadi ◽  
Simon S. Park
Keyword(s):  
Time Domain ◽  
Chip Thickness ◽  
Experimental Tests ◽  
Micro Milling ◽  
Chatter Stability ◽  
Workpiece Material ◽  
Process Damping ◽  
Milling Operations ◽  
Milling Operation ◽  
Cutting Mechanisms

Micro milling operations utilize miniature tools to remove workpiece material, in order to create the desired 3D miniature components. One of the challenges in a micro milling operation is the unstable phenomenon called regenerative chatter. The occurrence of chatter in the micro domain, as in macro machining, is detrimental to part finishes and significantly reduces the longevity of tools. There are two different cutting mechanisms in micro milling operations, which are determined by the critical chip thickness. When the chip thickness is less than the critical chip thickness, no chip forms and ploughing occurs; whereas, when the chip thickness is greater than the critical chip thickness, a chip forms and shearing cutting happens. During each rotation of the tool, the cutting mechanisms switch from ploughing to shearing and vice versa. This paper introduces a time domain chatter model to investigate the effects of the ploughing and shearing mechanisms on stability. The model also considers the effects of process damping in micro milling, especially at low spindle speeds. Several experimental tests have been performed to validate the model.

Leakage characteristics of flanged pipe joints

1977 ◽  
Vol 12 (1) ◽  
pp. 29-36 ◽  
Author(s):  
H Fessler ◽  
D A Perry
Keyword(s):  
Surface Finish ◽  
Joint Surface ◽  
Clamping Force ◽  
Face Surface ◽  
Joint Efficiency ◽  
Wide Range ◽  
Pipe Joints ◽  
Surface Profiles ◽  
Leakage Characteristics ◽  
Gasket Material

Standard flanges for five widely differing pressure ratings, having a wide range of different joint surface profiles, were sealed by flat rubber or asbestos gaskets. Different initial bolt tensions were applied and the variation of clamping force with internal pressure was measured up to leakage of the joint. The joint efficiency, defined as: (end thrust due to leakage pressure on bore area of pipe)/(total initial bolting force), is not affected by variations in joint-face surface finish if machining grooves across the joint surface are avoided. Minimum values of joint efficiency are given. The effects of gasket material, width and thickness and number of bolts on joint efficiency are considered.

Prediction of Surface Roughness in Compressed Air Jet Assisted High Speed End Milling of Silicon Using Diamond Coated Tools

2012 ◽  
Vol 576 ◽  
pp. 41-45
Author(s):  
A.K.M. Nurul Amin ◽  
M.A. Mahmud ◽  
M.D. Arif
Keyword(s):  
Mathematical Model ◽  
Surface Roughness ◽  
Surface Finish ◽  
High Speed ◽  
End Milling ◽  
Silicon Wafers ◽  
Compressed Air ◽  
Machining Parameters ◽  
High Quality ◽  
Ductile Mode

The majority of semiconductor devices are made up of silicon wafers. Manufacturing of high-quality silicon wafers includes numerous machining processes, including end milling. In order to end mill silicon to a nano-meteric surface finish, it is crucial to determine the effect of machining parameters, which influence the machining transition from brittle to ductile mode. Thus, this paper presents a novel experimental technique to study the effects of machining parameters in high speed end milling of silicon. The application of compressed air, in order to blow away the chips formed, is also investigated. The machining parameters’ ranges which facilitate the transition from brittle to ductile mode cutting as well as enable the attainment of high quality surface finish and integrity are identified. Mathematical model of the response parameter, the average surface roughness (Ra) is subsequently developed using RSM in terms of the machining parameters. The model was determined, by Analysis of Variance (ANOVA), to have a confidence level of 95%. The experimental results show that the developed mathematical model can effectively describe the performance indicators within the controlled limits of the factors that are being considered.

OPTIMISING CUTTING PARAMETERS FOR HOT TURNING ON EN31 MATERIAL

2021 ◽  
Vol 5 (10) ◽  
Author(s):  
Prof. Hemant k. Baitule ◽  
Satish Rahangdale ◽  
Vaibhav Kamane ◽  
Saurabh Yende
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Machining Process ◽  
Depth Of Cut ◽  
Multiple Time ◽  
Turning Process ◽  
Workpiece Material ◽  
Hot Turning

In any type of machining process the surface roughness plays an important role. In these the product is judge on the basis of their (surface roughness) surface finish. In machining process there are four main cutting parameter i.e. cutting speed, feed rate, depth of cut, spindle speed. For obtaining good surface finish, we can use the hot turning process. In hot turning process we heat the workpiece material and perform turning process multiple time and obtain the reading. The taguchi method is design to perform an experiment and L18 experiment were performed. The result is analyzed by using the analysis of variance (ANOVA) method. The result Obtain by this method may be useful for many other researchers.

Study on carbon epoxy composite surfaces machined by abrasive water jet machining

2018 ◽  
Vol 53 (20) ◽  
pp. 2909-2924 ◽  
Author(s):  
Ajit Dhanawade ◽  
Shailendra Kumar
Keyword(s):  
Surface Roughness ◽  
Composite Material ◽  
Process Parameters ◽  
Surface Finish ◽  
Epoxy Composite ◽  
Water Jet ◽  
Machining Parameters ◽  
Abrasive Water Jet ◽  
Abrasive Water Jet Machining ◽  
Pull Out

Traditional machining of carbon epoxy composite material is difficult due to excessive tool wear, excessive stresses and heat generation, delamination, high surface waviness, etc. In the present paper, research work involved in the experimental study of abrasive water jet machining of carbon epoxy composite material is described. The aim of present work is to improve surface finish and studying defects in machined samples. Taguchi's orthogonal array approach is used to design experiments. Process parameters namely hydraulic pressure, traverse rate, stand-off distance and abrasive mass flow rate are considered for this study. Analysis of machined surfaces and kerf quality is carried out using scanning electron microscope to evaluate microscopic features. Further, the effect of machining parameters on surface roughness is investigated using analysis of variance approach. It is found that traverse rate and pressure are most significant parameters to control surface roughness. Optimization of process parameters is performed using grey relational analysis. Thereafter, confirmation tests are carried out to verify the improvement in the surface quality with optimum set of process parameters. It is found that surface finish of machined samples is improved by 10.75% with optimum levels of process parameters. Defects like delamination, fiber pull-out and abrasive embedment are also studied using SEM. It is observed that delamination and fiber pull-out are prominent in samples machined at low pressure and high traverse rate.

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