scholarly journals The Effect of the Feed Direction on the Micro- and Macro Accuracy of 3D Ball-end Milling of Chromium-Molybdenum Alloy Steel

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4038
Author(s):  
Balázs Mikó ◽  
Bálint Varga ◽  
Wojciech Zębala
Keyword(s):  
Surface Roughness ◽  
Metal Cutting ◽  
Tool Path ◽  
End Milling ◽  
Cutting Parameters ◽  
Machining Process ◽  
Free Form ◽  
Dimensional Error ◽  
Ball End Milling ◽  
Free Form Surfaces

The machining of free form surfaces is one of the most challenging problems in the field of metal cutting technology. The produced part and machining process should satisfy the working, accuracy, and financial requirements. The accuracy can describe dimensional, geometrical, and surface roughness parameters. In the current article, three of them are investigated in the case of the ball-end milling of a convex and concave cylindrical surface form 42CrMo4 steel alloy. The effect of the tool path direction is investigated and the other cutting parameters are constant. The surface roughness and the geometric error are measured by contact methods. Based on the results, the surface roughness, dimensional error, and the geometrical error mean different aspects of the accuracy, but they are not independent from each other. The investigated input parameters have a similar effect on them. The regression analyses result a very good liner regression for geometric errors and shows the importance of surface roughness.

Surface Quality Prediction in Case of Steep Free Form Surface Milling

2016 ◽  
Vol 686 ◽  
pp. 119-124 ◽  
Author(s):  
Balázs Mikó
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Tool Path ◽  
Complex Geometry ◽  
Cutting Parameters ◽  
Free Form ◽  
Milling Cutter ◽  
Good Surface ◽  
2.5D Milling ◽  
Free Form Surfaces

The machining of free form surfaces is a current and important issue in die and mould industry. Beside the complex geometry, an accurate and productive machining and good surface quality are needed. The finishing milling carried out by a ball-end or toroid milling cutter defines the surface quality, which is characterized by the surface roughness and the tool path trace. The surface quality is defined by the properties of the milling cutter, the type of surface and its position, as well as the cutting parameters. This article focuses on the z-level milling of steep surfaces by 2.5D milling strategy. The importance of the different elements of the tool path is presented, the effect of cutting parameters is investigated, and a formula to predict the surface roughness is suggested.

Evaluation of Surface Roughness in Five-Axis Ball-End Milling

2020 ◽  
pp. 21-31
Author(s):  
B.B. Ponomarev ◽  
S.H. Nguyen
Keyword(s):  
Surface Roughness ◽  
Tilt Angle ◽  
End Milling ◽  
Free Form ◽  
Tool Orientation ◽  
Ball End Milling ◽  
Lead Angle ◽  
Tool Tilt Angle ◽  
Five Axis ◽  
Free Form Surfaces

Unlike three-axis machining, five-axis machining allows the end tool or workpiece to be oriented at any angle relative to the machine axis OZ. It can be achieved by changing the values of the tool tilt angle and lead angle relative to the surface normal in the contact zone of the tool surface and the workpiece, taking into account the direction of the table feed. The article presents experimental results of analyzing the influences of tool orientation on transverse roughness during ball end milling using 2-flute and 4-flute 8 mm diameter mills. The analysis the arithmetic mean deviation of the assessed profile at various values of tool tilt angle and lead angle showed that the position of the tool point with a zero cutting speed significantly affects the surface quality. The results of the evaluation of the tool orientation influence on the surface roughness enable the selection of optimal tool orientation angles when developing control programs for end milling of free-form surfaces on five-axis CNC milling machines.

Parameter Optimization of Ball End Milling Process on Inconel 718 Using RSM and TLBO Algorithm

2015 ◽  
Vol 15 (3) ◽  
pp. 293-300 ◽  
Author(s):  
Nandkumar N. Bhopale ◽  
Nilesh Nikam ◽  
Raju S. Pawade
Keyword(s):  
Surface Roughness ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Surface Integrity ◽  
Inconel 718 ◽  
Tool Path ◽  
End Milling ◽  
Spindle Speed ◽  
Depth Of Cut ◽  
Ball End Milling

AbstractThis paper presents the application of Response Surface Methodology (RSM) coupled with Teaching Learning Based Optimization Technique (TLBO) for optimizing surface integrity of thin cantilever type Inconel 718 workpiece in ball end milling. The machining and tool related parameters like spindle speed, milling feed, axial depth of cut and tool path orientation are optimized with considerations of multiple response like deflection, surface roughness, and micro hardness of plate. Mathematical relationship between process parameters and deflection, surface roughness and microhardness are found out by using response surface methodology. It is observed that after optimizing the process that at the spindle speed of 2,000 rpm, feed 0.05 mm/tooth/rev, plate thickness of 5.5 mm and 15° workpiece inclination with horizontal tool path gives favorable surface integrity.

Mechanistic Modeling of the Ball End Milling Process for Multi-Axis Machining of Free-Form Surfaces

2000 ◽  
Vol 123 (3) ◽  
pp. 369-379 ◽  
Author(s):  
Rixin Zhu ◽  
Shiv G. Kapoor ◽  
Richard E. DeVor
Keyword(s):  
End Milling ◽  
Chip Thickness ◽  
Mechanistic Modeling ◽  
Free Form ◽  
Surface Geometry ◽  
Workpiece Surface ◽  
Ball End Milling ◽  
Modeling Approach ◽  
Free Form Surfaces ◽  
Cutting Point

A mechanistic modeling approach to predicting cutting forces is developed for multi-axis ball end milling of free-form surfaces. The workpiece surface is represented by discretized point vectors. The modeling approach employs the cutting edge profile in either analytical or measured form. The engaged cut geometry is determined by classification of the elemental cutting point positions with respect to the workpiece surface. The chip load model determines the undeformed chip thickness distribution along the cutting edges with consideration of various process faults. Given a 5-axis tool path in a cutter location file, shape driving profiles are generated and piecewise ruled surfaces are used to construct the tool swept envelope. The tool swept envelope is then used to update the workpiece surface geometry employing the Z-map method. A series of 3-axis and 5-axis surface machining tests on Ti6A14V were conducted to validate the model. The model shows good computational efficiency, and the force predictions are found in good agreement with the measured data.

Finding Cutter Engagement for Ball End Milling of Tessellated Free-Form Surfaces

2005 ◽  
Author(s):  
Zhiyang Yao
Keyword(s):  
Surface Finish ◽  
Feed Rate ◽  
End Milling ◽  
Geometric Algorithms ◽  
Free Form ◽  
Ball End Milling ◽  
Final Surface ◽  
End Mills ◽  
Free Form Surfaces ◽  
Final Surface Finish

In fabricating free-form surfaces, ball end mills are mainly used to reach the final surface finish requirements. In the milling processes, cutter engagement value measures what portion of the cutter is involved in machining at a given instant of time. This paper presents geometric algorithms for estimating cutter engagement values for ball end milling processes of tessellated free-form surfaces. The cutter engagement value calculated here can be used later on in generating efficient cutter paths, as well as performing adaptive feed rate controls.

Multiresolution Representation of a Geometric Model for Free-Form Surfaces Turning Based on Mesh Simplification

2013 ◽  
Vol 823 ◽  
pp. 265-269
Author(s):  
Qing Zou ◽  
Jian Feng Lu ◽  
Yu Jiang Gao ◽  
Tao Wang ◽  
Jian Ning Yao ◽  
...  
Keyword(s):  
Tool Path ◽  
Control Method ◽  
Geometric Model ◽  
Mesh Simplification ◽  
Diamond Turning ◽  
Machining Process ◽  
Free Form ◽  
Multiresolution Representation ◽  
Resolution Model ◽  
Free Form Surfaces

In this paper, a new multi-resolution representation (MRR) of a series of intermediate shape models for FTS diamond turning based on mesh simplification is proposed. In this MRR, geometric relations between each resolution model can be controlled so as to avoid overcut and to level the cutting loads. The new control method for MRR is based on an improved Edge Collapse Algorithm with consideration of the curvature factor. In addition, the calculation method of machining allowance and tool path generation method are proposed to support the machining process. The effectiveness of the MRR has been verified through simulation.

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