A New Algorithm for the Numerical Simulation of Machined Surface Topography in Multiaxis Ball-End Milling

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Wei-Hong Zhang ◽  
Gang Tan ◽  
Min Wan ◽  
Tong Gao ◽  
David Hicham Bassir
Keyword(s):  
Numerical Simulation ◽  
Surface Topography ◽  
End Milling ◽  
Computing Time ◽  
Cutting Edge ◽  
Machining Parameters ◽  
Step Method ◽  
Time Step ◽  
Machined Surface ◽  
Ball End Milling

In milling process, surface topography is a significant factor that affects directly the surface integrity and constitutes a supplement to the form error associated with the workpiece deformation. Based on the tool machining paths and the trajectory equation of the cutting edge relative to the workpiece, a new and general iterative algorithm is developed here for the numerical simulation of the machined surface topography in multiaxis ball-end milling. The influences of machining parameters such as the milling modes, cutter runout, cutter inclination direction, and inclination angle upon the topography and surface roughness values are studied in detail. Compared with existing methods, the basic advantages and novelties of the proposed method can be resumed below. First, it is unnecessary to discretize the cutting edge and tool feed motion and rotation motion. Second, influences of cutting modes and cutter inclinations are studied systematically and explicitly for the first time. The generality of the algorithm makes it possible to calculate the pointwise topography value on any sculptured surface of the workpiece. Besides, the proposed method is proved to be more efficient in saving computing time than the time step method that is commonly used. Finally, some examples are presented and simulation results are compared with experimental ones.

Numerical Simulation of Machined Surface Topography and Roughness in Milling Process

2005 ◽  
Vol 128 (1) ◽  
pp. 96-103 ◽  
Author(s):  
Tong Gao ◽  
Weihong Zhang ◽  
Kepeng Qiu ◽  
Min Wan
Keyword(s):  
Surface Topography ◽  
End Milling ◽  
Equation System ◽  
Milling Process ◽  
Cutting Edge ◽  
Machined Surface ◽  
Ball End Milling ◽  
Starting Point ◽  
Trajectory Equation ◽  
End Milling Process

Machined surface topography is very critical since it directly affects the surface quality, especially the surface roughness. Based on the trajectory equations of the cutting edge relative to the workpiece, a new method is developed for the prediction of machined surface topography. This method has the advantage of simplicity and is a mesh-independent direct computing method over the traditional interpolation scheme. It is unnecessary to discretize the cutting edge or to mesh the workpiece. The topography value of any point on the machined surface can be calculated directly, and the spindle runout can be taken into account. The simulation of machined surface topography is successfully carried out for both end and ball-end milling processes. In the end milling process, a fast convergence of solving the trajectory equation system by the Newton-Raphson method can be ensured for topography simulation at any node on the machined surface thanks to the appropriate choice of the starting point. In the ball-end milling process, this general algorithm is applicable to any machined surface. Finally, the validity of the method is demonstrated by several simulation examples. Simulation results are compared to experimental ones, and a good agreement is obtained.

Surface Topography and Roughness Simulations for 5-Axis Ball-End Milling

2009 ◽  
Vol 69-70 ◽  
pp. 471-475 ◽  
Author(s):  
Shi Guo Han ◽  
Jun Zhao ◽  
Xiao Feng Zhang
Keyword(s):  
Surface Topography ◽  
Surface Quality ◽  
High Speed ◽  
End Milling ◽  
Analytical Form ◽  
Influential Factors ◽  
Sculptured Surfaces ◽  
Machined Surface ◽  
Ball End Milling ◽  
Five Axis

In five-axis high speed milling of freeform surface with ball-end cutters, unwanted machining results are usually introduced by some error effects. Hence precise modeling and simulation of milled sculptured surfaces topography and roughness is the key to obtain optimal process parameters, satisfactory surface quality and high machining efficiency. In this paper, a predictive model for sculptured surface topography and roughness of ball-end milling is developed. Firstly, a mathematical model including both the relative motion of the cutter-workpiece couple and some influential factors on machined surface quality such as the tool runout, tool deflection and tool wear is proposed, and subsequently the analytical form of the tool swept envelope is derived by means of homogeneous coordinate transformation. Then the minimal z-values of the corresponding points lied in discrete cutting edges model and Z-map workpiece model are used to update the workpiece surface topography and to calculate 3D surface roughness. Finally, the simulation algorithm is realized with Matlab software. A series of machining tests on 3Cr2MoNi steel are conducted to validate the model, and the machined surface topography is found in good accordance with the simulation result.

scholarly journals Modeling and Analysis of Micro Surface Topography from Ball-End Milling in a Trochoidal Milling Mode

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1203
Author(s):  
Yongheng Dong ◽  
Shujuan Li ◽  
Qian Zhang ◽  
Pengyang Li ◽  
Zhen Jia ◽  
...  
Keyword(s):  
Surface Topography ◽  
High Speed ◽  
End Milling ◽  
Complex Surface ◽  
Summation Method ◽  
Time Step ◽  
Ball End Milling ◽  
Map Algorithm ◽  
Trochoidal Milling ◽  
Grid Nodes

The trochoidal milling mode is widely used in high-speed machining, and due to good adaptability and flexible posture adjustment, ball-end milling cutters are conducive to complex surface machining with this mode. However, the processes of material removal and formation of machined micro surfaces are very difficult to describe as the profile of cutter teeth is complex and the trajectory direction changes continuously during the trochoidal milling process. A modeling method for the generation of micro surface topography of ball-end milling in the trochoidal milling mode is put forward. In this method, the locus equation of each cutter tooth is established based on the principle of homogeneous coordinate transformation, after which a Z-MAP algorithm is designed to simulate the micro surface topography. The Z-MAP algorithm can quickly obtain the part grid nodes potentially swept by the cutter tooth within a unit time step through the establishment of servo rectangular encirclement and instantaneous sweeping quadrilateral of the element of cutter teeth; the part grid nodes actually swept are further determined through an angle summation method, and the height coordinate is calculated with the method of linear interpolation according to Taylor’s formula of multivariate functions. Experiments showed that the micro surface topography resulting from ball-end milling in the trochoidal milling mode had high consistency with the simulation, which indicates that the proposed method can predict micro surface topography in practical manufacturing. In addition, a comparison of micro surface topography between trochoidal milling and ordinary straight-linear milling was conducted, and the results showed that the former was overall superior to the latter in resulting characteristics. Based on this conclusion, the influences of cutting parameters of ball-end trochoidal milling on surface characteristics, particularly amplitude and function, were analyzed according to the simulated micro surface topography data.

Surface quality analysis in ball end milling of Inconel 718 cantilevers by response surface methodology

2016 ◽  
Vol 231 (4) ◽  
pp. 628-640 ◽  
Author(s):  
Nandkumar N Bhopale ◽  
Raju S Pawade ◽  
Suhas S Joshi
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Inconel 718 ◽  
Tool Path ◽  
End Milling ◽  
Machining Parameters ◽  
Machined Surface ◽  
Ball End Milling ◽  
Fixed End ◽  
Side Flow

The ball end milling process is commonly used for generating complex three-dimensional sculptured surfaces with definite curvature. In such cases, variation of surface properties along with the machined surface is not well understood. Therefore, this article investigates the effect of machining parameters on the quality of surface in ball end milling of thin-shaped cantilever of Inconel 718. A distinct variation is also observed in the measured values of deflection of workpiece: surface roughness and surface damage in different regions, that is, fixed end, mid portion and free end of machined surface. The experiments were conducted according to the central composite design with four factors, namely, cutting speed, feed, workpiece thickness and workpiece inclination with tool path orientation. It is observed that the process parameters have statistically significant effect on machined surface of Inconel 718. Horizontal tool path condition during milling is most favourable in all aspects of surface quality with high speed and lower feed. The surface roughness values at the fixed end of plate are less as compared with that of mid portion and free end sides. Scanning electron microscope images show various defects such as side flow, smeared layer, microparticle, grooves and feed marks.

Surface Integrity Studies in Ball End Milling of Thin Shaped Cantilever Inconel 718

2014 ◽  
Author(s):  
Nandkumar N. Bhopale ◽  
Raju S. Pawade
Keyword(s):  
Surface Integrity ◽  
Inconel 718 ◽  
Tool Path ◽  
Surface Defects ◽  
End Milling ◽  
Surface Region ◽  
Lower Surface ◽  
Machined Surface ◽  
Ball End Milling ◽  
Integrity Analysis

The paper presents the surface integrity analysis in ball end milling of thin shaped cantilever plate of Inconel 718. It is noticed that the workpiece deflection has significantly contributed to machined surface integrity in terms of surface topography and subsurface microhardness. The ball end milling performed with 15° workpiece inclination with horizontal tool path produced higher surface integrity which varies with the location of machined surface region. In general, the mid portion of the machined plate shows lower surface roughness and microhardness with less surface defects.

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