Optimal tool orientation generation and chip volume/cutting force predictions for 5-axis CNC machining of curved surfaces using flat-end mills

Jet engine impeller blades are flank-milled with tapered, helical, ball-end mills on five-axis machining centers. The impellers are made from difficult-to-cut titanium or nickel alloys, and the blades must be machined within tight tolerances. As a consequence, deflections of the tool and flexible workpiece can jeopardize the precision of the impellers during milling. This work is the first of a two part paper on cutting force prediction and feed optimization for the five-axis flank milling of an impeller. In Part I, a mathematical model for predicting cutting forces is presented for five-axis machining with tapered, helical, ball-end mills with variable pitch and serrated flutes. The cutter is divided axially into a number of differential elements, each with its own feed coordinate system due to five-axis motion. At each element, the total velocity due to translation and rotation is split into horizontal and vertical feed components, which are used to calculate total chip thickness along the cutting edge. The cutting forces for each element are calculated by transforming friction angle, shear stress and shear angle from an orthogonal cutting database to the oblique cutting plane. The distributed cutting load is digitally summed to obtain the total forces acting on the cutter and blade. The model can be used for general five-axis flank milling processes, and supports a variety of cutting tools. Predicted cutting force measurements are shown to be in reasonable agreement with those collected during a roughing operation on a prototype integrally bladed rotor (IBR).

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ANALYSIS OF THE CORRELATION BETWEEN FRACTAL STRUCTURE OF CUTTING FORCE SIGNAL AND SURFACE ROUGHNESS OF MACHINED WORKPIECE IN END MILLING OPERATION

Fractals ◽

10.1142/s0218348x19500130 ◽

2019 ◽

Vol 27 (02) ◽

pp. 1950013 ◽

Cited By ~ 23

Author(s):

AHMAD THUFFAIL THASTHAKEER ◽

ALI AKHAVAN FARID ◽

CHANG TECK SENG ◽

HAMIDREZA NAMAZI

Keyword(s):

Surface Roughness ◽

Cutting Force ◽

Surface Quality ◽

Cutting Forces ◽

End Milling ◽

Complex Structure ◽

Machined Surface ◽

End Mills ◽

Machining Operations

Analysis of the machined surface is one of the major issues in machining operations. On the other hand, investigating about the variations of cutting forces in machining operation has great importance. Since variations of cutting forces affect the surface quality of machined workpiece, therefore, analysis of the correlation between cutting forces and surface roughness of machined workpiece is very important. In this paper, we employ fractal analysis in order to investigate about the complex structure of cutting forces and relate them to the surface quality of machined workpiece. The experiments have been conducted in different conditions that were selected based on cutting depths, type of cutting tool (serrated versus. square end mills) and machining conditions (wet and dry machining). The result of analysis showed that among all comparisons, we could only see the correlation between complex structure of cutting force and the surface roughness of machined workpiece in case of using serrated end mill in wet machining condition. The employed methodology in this research can be widely applied to other types of machining operations to analyze the effect of variations of different parameters on variability of cutting forces and surface roughness of machined workpiece and then investigate about their correlation.

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Development Research of the End Mills Grinding Programming System Based on MATLAB

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.422.242 ◽

2013 ◽

Vol 422 ◽

pp. 242-246

Author(s):

Hong Jun Zhang ◽

Jian Guang Li ◽

Tian Wei Zhang

Keyword(s):

Simulation Software ◽

Cnc Machining ◽

Programming System ◽

Development Research ◽

Machining Simulation ◽

Nc Code ◽

Cnc Grinding ◽

End Mills ◽

Five Axis ◽

Grinding Simulation

Using MATLAB for development tools,we has developed a set of end mills CNC grinding programming system by analysis the end mills grinding craft ,research on cutter location trajectory calculation and post-processing technology. Meanwhile, build a five-axis tool grinder grinding simulation processing by VERICUT(a kind of CNC machining simulation software), through the edge grinding simulation , we confirm the cutter location trajectory and the NC code is errorless.

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High-Quality End Milling of CFRP – Inclination Milling with High-Helix End Mill –

International Journal of Automation Technology ◽

10.20965/ijat.2016.p0372 ◽

2016 ◽

Vol 10 (3) ◽

pp. 372-380 ◽

Cited By ~ 1

Author(s):

Akira Hosokawa ◽

◽

Naoya Hirose ◽

Takashi Ueda ◽

Tomohiro Koyano ◽

...

Keyword(s):

Tool Wear ◽

Cutting Force ◽

Surface Integrity ◽

Helix Angle ◽

Surface Generation ◽

End Mill ◽

Side Milling ◽

Pull Out ◽

End Mills ◽

Coated Carbide

Side milling tests of CFRP (carbon fiber reinforced plastics) containing thermosetting resin are carried out by TiAlN/AlCrN-coated, H2-free DLC (diamond-like carbon)-coated, and CVD diamond-coated carbide end mills without coolant. Two types of end mills having different helix angles of 30° and 60° are used. The film thickness and surface smoothness are varied for the DLC-coated end mills. The cutting characteristics are evaluated by tool wear and surface integrity (i.e., 3D profiles of the machined surface, generation of fluffing, delamination, and pull-out of the carbon fibers). The cutting force and tool flank temperature are also examined for the two types of CFRP composites and the helix angle of the end mill. “Inclination milling,”in which the end mill is tilted so that the resultant cutting force acts parallel to the work surface, is proposed as a novel technique to be used with a high-helix angle end mill. This unique approach enables the reduction of tool wear and improves the surface integrity of machined CFRP surfaces.

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Cutting Path Design to Minimize Workpiece Displacement at Cutting Point: Milling of Thin-Walled Parts

International Journal of Automation Technology ◽

10.20965/ijat.2012.p0638 ◽

2012 ◽

Vol 6 (5) ◽

pp. 638-647 ◽

Cited By ~ 4

Author(s):

Yusuke Koike ◽

◽

Atsushi Matsubara ◽

Shinji Nishiwaki ◽

Kazuhiro Izui ◽

...

Keyword(s):

Cutting Force ◽

Material Removal ◽

Tool Orientation ◽

Numerical Example ◽

Path Design ◽

Minimum Displacement ◽

Low Stiffness ◽

Thin Walled ◽

Cutting Path ◽

Cutting Point

Vibrations of a tool or workpiece during cutting operations shorten tool life and causes unwanted surface roughness. In this report, we propose an algorithm for determining the sequence of material removal, tool orientation, and feed directions, an algorithm minimizes workpiece displacements by considering workpiece stiffness and cutting force. In this research, the cutting path consists of the material removal sequence, tool orientation and feed directions. The material removal sequence changes the workpiece compliancematrix at the cutting points, and the feed directions and tool orientation change the direction of the cutting force. In our algorithm, workpiece displacements are reduced by changing the material removal sequence and applying the cutting force in the direction of higher workpiece stiffness. A numerical example demonstrates how the algorithm obtains appropriate cutting paths to mill a cantilever form. In the numerical example, three optimized cutting paths are compared with an unoptimized cutting path, a path used by an expert and based on the expert’s personal experience, to machine a low-stiffness workpiece. The obtained material removal sequence of the minimax compliance path is almost the same as that of the unoptimized cutting path. Workpiece displacements at the cutting point of three optimized cutting paths are approximately 10% smaller than those of the unoptimized cutting path. The minimum displacement path is the best of these three optimized cutting paths because fluctuations in workpiece displacements at cutting point are the smallest. These optimized cutting paths show the cutting path strategy as a rough cutting path for machining the thin-walled cantilever.

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