Bio: A.A. Radwan is an academic researcher from Valparaiso University. The author has contributed to research in topics: High-speed steel & Machining. The author has an hindex of 1, co-authored 1 publications receiving 11 citations.
TL;DR: In this paper, an experimental analysis was performed to evaluate the width of the secondary deformation zone and the mean coefficient of friction during the machining of 5083-H34 aluminum alloy.
Abstract: An experimental analysis was performed to evaluate the width of the secondary deformation zone and the mean coefficient of friction during the machining of 5083-H34 aluminum alloy. Dry orthogonal cutting tests using high speed steel and sintered carbide tools of different rake angles were carried out at a wide range of feed rates at constant cutting speed for tubular workpieces. The width of the secondary deformation zone and the mean coefficient of friction were found to be direct functions of the parameters involved in the cutting process. The results were analyzed in terms of the variation in the mean tool-chip contact temperature and its influence on the specific tangential load and specific normal pressure on the tool face.
TL;DR: In this paper, the analytical and experimental study on the high-speed face milling of 7075-T6 aluminum alloys with a single insert fly-cutter was conducted.
Abstract: This research is concerned with the analytical and experimental study on the high-speed face milling of 7075-T6 aluminum alloys with a single insert fly-cutter. The results are analyzed in terms of cutting forces, chip morphology, and surface integrity of the workpiece machined with carbide and diamond inserts. It is shown that a high cutting speed leads to a high chip flow angle, very low thrust forces and a high shear angle, while producing a thinner chip. Chip morphology studies indicate that shear localization can occur at higher feeds even for 7075-T6, which is known to produce continuous chips. The resultant compressive residual stresses are shown for the variation of cutting parameters and cutting tool material. The analysis of the high-speed cutting process mechanics is presented, based on the calculation results using extended oblique machining theory and finite element simulation.
TL;DR: In this paper, the authors used a numerical high-speed camera to take photographs of chips during the cutting process for a large range of speeds, ranging from 17 to 60m/s.
Abstract: The originality of this work consists in taking photographs of chips during the cutting process for a large range of speeds. Contrary to methods usually used such as the quick stop in which root chips are analyzed after an abrupt interruption of the cutting, the proposed process photographs the chip geometry during its elaboration. An original device reproducing perfectly orthogonal cutting conditions is used because it allows a good accessibility to the zone of machining and reduces considerably the vibrations found in conventional machining tests. A large range of cutting velocities is investigated (from 17 to 60 m/s) for a middle hard steel (French Standards XC18). The experimental measures of the root chip geometry, more specifically the tool-chip contact length and the shear angle, are obtained from an analysis of the pictures obtained with a numerical high-speed camera. These geometrical characteristics of chips are studied for various cutting speeds, at the three rake angles −5, 0, +5° and for different depths of cut reaching 0.65 mm.
TL;DR: In this paper, the effects of tool edge radius on the frictional contact and flow stagnation phenomenon, the stick-slide behavior and contact stress distributions, the evolutions of contact length, and the relationship between material deformation and total contact length were investigated.
Abstract: The contact phenomenon during micromachining is complicated due to the tool edge radius. This paper presents investigation of the effects of tool edge radius on the frictional contact and flow stagnation phenomenon, the stick–slide behavior and contact stress distributions, the evolutions of contact length, and the relationship between material deformation and total contact length. Through the arbitrary Lagrangian–Eulerian FE modeling approach, our findings revealed that the flow stagnation during material separations could be attributed to the counterbalance of shear contact components and it appeared to be insensitive to machining magnitude where a constant stagnation point angle of 58.5±0.5° was determined for a wide range of undeformed chip thicknesses. Three distinctive sticking and sliding regions associated with the flow stagnation phenomenon on the cutting tool were discovered following the identification of two stress criteria for sticking, τf=0 and/or τf=kf. In addition, the influence of tool edge radius on contact length and material deformation was determined and a theoretical model for the contact length of tool-based micromachining was proposed. It was also observed that tool–chip contact evolved in two successive stages through a series of intermittent sticking and sliding interactions as governed by the undeformed chip thickness and the transition of effective rake angle. An ultraprecision machining setup coupled with a high-speed and small field-of-view photography technique was proposed for experimental substantiation of the numerical results.
TL;DR: In this article, the machinability characteristics of Incoloy 825 using an uncoated tool, chemical vapor deposition of a bilayer of TiCN/Al2O3, and physical vapor deposition (PVD) of alternate layers of TiAlN/TiN-coated tools under varying machining conditions were investigated.
Abstract: With wide applications of nickel-based superalloys in strategic fields, it has become increasingly necessary to evaluate the performance of different advanced cutting tools for machining such alloys. With a view to recommend a suitable cutting tool, the present work investigated various machinability characteristics of Incoloy 825 using an uncoated tool, chemical vapor deposition (CVD) of a bilayer of TiCN/Al2O3, and physical vapor deposition (PVD) of alternate layers of TiAlN/TiN-coated tools under varying machining conditions. The influence of cutting speed (51, 84, and 124 m/min) as well as feed (0.08, 0.14, and 0.2 mm/rev) was comparatively evaluated on surface roughness, cutting temperature, cutting force, coefficient of friction, chip thickness, and tool wear using different cutting tools. Although the CVD-coated tool was not useful in decreasing surface roughness and temperature, a significant reduction in cutting force and tool wear could be achieved with the same coated tool under a high ...
15 Nov 2005