Gloss Estimating Method of Finished Surface Machined by Ball Nose End-Milling under Constant Contact Angle with a Five-Axis Controlled Machining Center

2012 ◽  
Vol 516 ◽  
pp. 475-480
Author(s):  
Kenichi Terada ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Keiji Ogawa
Keyword(s):  
Feed Rate ◽  
End Milling ◽  
Work Piece ◽  
Machined Surface ◽  
Ball End Milling ◽  
Machining Center ◽  
Reflected Light ◽  
Finished Surface ◽  
Constant Contact Angle ◽  
Five Axis

In recent years, studies have been conducted about creating metal moulds using a five-axis controlled machining centre with ball end milling. Most of these reports concern the programming of CAM based on geometry. However, there have been few reports related to polish-less finished surface. Furthermore, a specular surface like a mirror and finishing under a constant angle between ball end milling and the work piece have not been investigated. Therefore, this paper deals with the gloss of the machined surface when feed rate and pick-feed rate are changed to maintain constant surface roughness considering tool run-out under the condition that the angle between the tool and work piece in contact are inclined at 15. However, by changing the combination of feed rate and pick-feed rate, various specular changes and direction of disposition of reflected light were obtained. Therefore, we suggest a new method of evaluating the gloss of these finished surfaces. Comparing results by the proposed method with ones by a glossmeter, it is clear that an appropriate ratio of feed rate and pick-feed rate is important for obtaining finished surface. Moreover, it is demonstrated that the proposed method is effective for estimating the gloss of the machined surface.

Sensitivity Analysis of Error Motions and Geometric Errors in the Case of Sphere-Shaped Workpiece

2020 ◽  
Author(s):  
Zongze Li ◽  
Ryuta Sato ◽  
Keiichi Shirase
Keyword(s):  
Sensitivity Analysis ◽  
Machine Tools ◽  
End Milling ◽  
Geometric Errors ◽  
Machined Surface ◽  
Error Sources ◽  
Motion Error ◽  
Machining Center ◽  
Machining Errors ◽  
Five Axis

Abstract Motion error of machine tool feed axes influences the machined workpiece accuracy. However, the influences of each error sources are not identical; some errors do not influence the machined surface although some error have significant influences. In addition, five-axis machine tools have more error source than conventional three-axis machine tools, and it is very tough to predict the geometric errors of the machined surface. This study proposes a method to analyze the relationships between the each error sources and the error of the machined surface. In this study, a kind of sphere-shaped workpiece is taken as a sample to explain how the sensitivity analysis makes sense in ball-end milling. The results show that the method can be applied for the axial errors, such as motion reversal errors, to make it clearer to obverse the extent of each errors. In addition, the results also show that the presented sensitivity analysis is useful to investigate that how the geometric errors influence the sphere surface accuracy. It can be proved that the presented method can help the five-axis machining center users to predict the machining errors on the designed surface of each axes error motions.

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 Experimental Study on Surface Integrity of Titanium Alloy Ti6Al4V by Ball End Milling

2018 ◽  
Vol 14 (1) ◽  
pp. 115-121 ◽  
Author(s):  
Pun Krishna Kaway ◽  
Xueping Zhang
Keyword(s):  
Titanium Alloy ◽  
Surface Integrity ◽  
Feed Rate ◽  
End Milling ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Machined Surface ◽  
Ball End Milling ◽  
Titanium Alloy Ti6al4v ◽  
Cutting Speeds

Titanium alloy, Ti6Al4V, has been widely used in aerospace, automotive, biomedical, and chemical industries due to its exceptional strength to weight ratio, high temperature performance, and corrosion resistance. However, machinability of Ti6Al4V is poor due to high strength at elevated temperatures, low modulus, and low thermal conductivity. Poor machinability of Ti6Al4V deteriorates the surface integrity of the machined surface. Poor surface integrity causes high machining cost, surface defects, initiate cracks, and premature failure of the machined surface. Thus, it is indispensable to obtain better surface integrity when machining titanium alloy Ti6Al4V. Cutting parameters such as cutting speed, feed rate, and depth of cut have significant effect on the surface integrity when machining titanium alloy Ti6Al4V. Hence, this study investigates surface integrity of Ti6Al4V by ball end milling at different cutting speeds, feed rates, and depth of cuts. Microstructure of subsurface is studied at different cutting speeds, feed rates, and depth of cuts. The results show that the depth of deformation of subsurface increases with increase in the cutting speed, feed rate, and depth of cut. Journal of the Institute of Engineering, 2018, 14(1): 115-121

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.

scholarly journals Experimental Verification of Chatter-Free Ball End Milling Strategy

2013 ◽  
Vol 7 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Lin Lu ◽  
◽  
Masahiko Sato ◽  
Hisataka Tanaka ◽  
Keyword(s):  
Cutting Tool ◽  
End Milling ◽  
Cutting Parameters ◽  
Cutting Condition ◽  
Chatter Stability ◽  
Chatter Vibration ◽  
Ball End Milling ◽  
Machining Center ◽  
Avoidance Control ◽  
Avoidance Strategy

Chatter vibration frequently occurs in ball end milling. If the characteristics of the cutting tool system and cutting process are known, chatter stability in ball end milling can be evaluated. Hence, in this paper, a chatter-avoidance strategy based on a regenerative chatter theory is proposed to prevent the occurrence of chatter. This consists of a simulation of chatter stability and cutting condition control. When the characteristics of a vibration system change, this chatter-avoidance strategy cannot cope with it. Therefore, another chatter-avoidance control algorism that changes cutting parameters on a machining center is proposed. This can adapt to the change in the characteristics of the vibration systemduring cutting. The effectiveness of the two chatter-avoidance methods proposed is examined through experiments.

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