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.

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.

Effect of the Working Diameter to the Surface Quality in Free-Form Surface Milling

2013 ◽  
Vol 581 ◽  
pp. 372-377 ◽  
Author(s):  
Balázs Mikó ◽  
Jozef Beňo
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Free Form ◽  
Effective Diameter ◽  
Test Part ◽  
Free Form Surface ◽  
Free Form Surfaces

The article presents the changing of the working diameter (effective diameter) and its effect to the surface roughness based on milling experiments of a test part in 3D milling of free-form surfaces. The position of the surface and the step depth determine the effective diameter, in case of constant revolution of the tool, the actual cutting speed and the minimal removable chip thickness will change. The article presents the result of the application of the constant cutting speed and feed per tooth.

Sampling Based Assessment of the Free-Form Milling Strategies

2016 ◽  
Vol 686 ◽  
pp. 51-56 ◽  
Author(s):  
Jozef Beňo ◽  
Ildikó Maňková ◽  
Dagmar Draganovská ◽  
Peter Ižol
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Statistical Distribution ◽  
Free Form ◽  
Surface Finishing ◽  
Free Form Surface ◽  
Surface Decomposition ◽  
Free Form Surfaces ◽  
Paper Author ◽  
Sampling Approach

In this paper, author introduce common needs of increasing surface quality in tool making, a sort of products manufactured by free form milling technology. Principles of the free-form surface decomposition into measurable samples are presented and that is a method of combining CAD modeling with design of sampling objects. Sampling objects are classed both according to their measurability and applied milling strategy. Authors verify experimentally their sampling approach for three milling strategies applied in surface finishing operations while free-form surfaces are investigated in terms of their signed radii. Verification of proposed approach is based on statistical distribution of the measured surface roughness data.

A Higher-Order Formula of Path Interval for Tool-Path Generation

2011 ◽  
Vol 5 (5) ◽  
pp. 663-668 ◽  
Author(s):  
Toshiyuki Obikawa ◽  
◽  
Tsutomu Sekine ◽  
Keyword(s):  
Surface Roughness ◽  
Fourth Order ◽  
Tool Path ◽  
Order Term ◽  
Computational Cost ◽  
Tool Path Generation ◽  
Free Form ◽  
Path Generation ◽  
Scallop Height ◽  
Free Form Surfaces

This paper presents a novel fourth-order formula for determining path intervals and comprehensively considers path interval formulas. In tool-path generation, a path interval is generally formulated as a scallopheight polynomial. Controlling scallop height in mechanical machining improves surface roughness or machining efficiency. We derived a novel fourth-order formula for determining path intervals after reviewing several formulas, then compared formulas. This clarified the differences between path interval formulas with graphic evidence. In micromechanical machining, an approximate expression has an advantage in computational cost but a disadvantage in accuracy. Although our proposed formula includes the fourth order-term scallop height, it requires low computational cost and can be applied to the determining path intervals for free-form surfaces in micromechanical machining. In addition, a correction method of the surface roughness on a free-form surface measured with a profilometer was proposed.

Analysis of Surface Roughness for High Speed Milling of a Magnesium Alloy Part

2013 ◽  
Vol 837 ◽  
pp. 33-38 ◽  
Author(s):  
Bogdan Chirita ◽  
Nicolae Catalin Tampu
Keyword(s):  
Surface Roughness ◽  
Magnesium Alloy ◽  
Surface Quality ◽  
Product Life Cycle ◽  
High Speed ◽  
Fatigue Behavior ◽  
Cutting Parameters ◽  
Good Surface ◽  
Cooling Conditions ◽  
Higher Temperature

Surface roughness represents an important characteristic in the appreciation of a part quality. A good surface quality can enhance corrosion resistance and fatigue behavior throughout product life cycle. Magnesium alloys have gained in the recent years a larger use due to an excellent ratio between mechanical strength and weight. Cooling conditions are particularly important when machining magnesium. The chips are flammable and highly reactive with water based fluids. Higher temperature favors also the formation [email protected] built-up edge and worsens surface quality. The present paper analyses the influence of cooling conditions and cutting parameters on surface roughness of the parts made of magnesium alloy. Using design of experiments technique, a series of experiments were organized and based on that a connection between surface quality and cutting conditions was established.

Manufacturability of Aircraft Winglet for Wind Tunnel Testing

2015 ◽  
Vol 830-831 ◽  
pp. 100-103
Author(s):  
L. Gopinath ◽  
S. Ravishankar
Keyword(s):  
Wind Tunnel ◽  
Metal Cutting ◽  
Tool Path ◽  
Cutting Parameters ◽  
Cnc Machining ◽  
Depth Of Cut ◽  
Manufacturing Strategy ◽  
Thin Sections ◽  
Good Surface ◽  
Good Surface Finish

The form, shape and dimensions of the scaled down winglet model become small and thin bringing complexity to manufacturing. The trailing edge tapers to a thickness varying from 0.065mm to 0.099mm along its length. The mounting portion of the winglet is provided with a close tolerance having a slot gap of 5mm and a depth of 35 mm with an angle. Additionally, wind tunnel models require good surface finish on the aerodynamic surfaces and this involves adopting a manufacturing strategy with a control over on the metal cutting parameters to be implemented on a three axes CNC machining centre. The winglet surface is divided into segments in order to handle the cutting forces on the varying aerodynamic cross section. Various metal cutting parameters such as tool path, cutter diameter, feed rate, depth of cut, spindle speed, etc., are evaluated by monitoring segments where the metal cutting is carried out [1] and flow of chips observed. Fixtures and lugs are planned effectively to accommodate the machining of the angular slot in a three axes machining centre itself. Routing of operations to handle the varying thin sections and realisation of the close tolerance slot has enabled a reliable manufacturing approach in an economical way.

Application of Convex Hull for Tool Interference Avoidance in 5-Axis CNC Machining

1996 ◽  
Author(s):  
Yuan-Shin Lee ◽  
Tien-Chien Chang
Keyword(s):  
Convex Hull ◽  
Tool Path ◽  
Correction Method ◽  
Nc Machining ◽  
Cnc Machining ◽  
Free Form ◽  
Interference Avoidance ◽  
Tool Interference ◽  
Free Form Surface ◽  
Free Form Surfaces

Abstract In this paper, a methodology of applying convex hull property in solving the tool interference problem is presented for 5-axis NC machining of free-form surfaces. Instead of exhausted point-by-point checking for possible tool interference, a quick checking can be done by using the convex hull constructed from the control polygon of free-form surface modeling. Global tool interference in 5-axis NC machining is detected using the convex hull of the free-form surface. A correction method for removing tool interference has also been developed to generate correct tool path for 5-axis NC machining. The inter-surface tool interference can be avoided by using the developed technique.

Force Measurement and Analysis for Magnetic Field–Assisted Finishing

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Vasishta Ganguly ◽  
Tony Schmitz ◽  
Arthur Graziano ◽  
Hitomi Yamaguchi
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Material Removal ◽  
Force Measurement ◽  
Removal Rate ◽  
Iron Particle ◽  
Free Form ◽  
Total Force ◽  
Polishing Force ◽  
Free Form Surfaces

Magnetic field–assisted finishing (MAF) is used to polish free-form surfaces. The material removal mechanism can be described as a flexible “magnetic brush” that consists of ferromagnetic particles and abrasives that arrange themselves in the working gap between the magnet and the workpiece. Relative motion between the brush and the workpiece causes microcutting and improves surface finish. In this study, the contributions of the magnetic and polishing force components to the total force were evaluated. The effect of varying the polishing conditions, such as the working gap and the size of the ferromagnetic iron particles, on polishing forces, surface roughness, and material removal rate was also analyzed. It was observed that the polishing forces varied considerably with working gap. Also, the iron particle size was found to have a strong relation to the rate at which the surface roughness improved. Surface roughness values of 2–3 nm were achieved.

An Analysis of Polishing Forces in Magnetic Field Assisted Finishing

2012 ◽  
Author(s):  
Vasishta Ganguly ◽  
Tony Schmitz ◽  
Arthur A. Graziano ◽  
Hitomi Yamaguchi
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Iron Particle ◽  
Free Form ◽  
Work Piece ◽  
Total Force ◽  
Polishing Force ◽  
Strong Relation ◽  
Force Components ◽  
Free Form Surfaces

Magnetic field assisted finishing (MAF) is used to polish free-form surfaces. The material removal mechanism can be described as a flexible “magnetic brush” that consists of ferromagnetic particles and abrasives that arrange themselves in the working gap between the magnet and the work piece. Relative motion between the brush and the work piece causes micro-cutting and improves surface finish. In this study, the contributions of the magnetic and polishing force components to the total force were evaluated. The effect of varying the polishing conditions, such as the working gap and the size of the ferromagnetic iron particles, on polishing forces and surface roughness was also analyzed. It was observed that the polishing forces varied considerably with working gap. Also, the iron particle size was found to have a strong relation to the rate at which the surface roughness decreased. Surface area roughness of 2–3 nm was achieved.

scholarly journals Influence of cutting parameters on surface quality when machining a CoCrWNi alloy

2018 ◽  
Vol 178 ◽  
pp. 01009
Author(s):  
Manuela-Roxana Dijmărescu ◽  
Ioan-Cristian Tarbă ◽  
Maria-Cristina Dijmărescu ◽  
Vlad Gheorghiţă
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Surface Quality ◽  
Cutting Parameters ◽  
Medical Applications ◽  
Medical Implants

Due to their excellent biocompatibility and mechanical properties, the use of Co-Cr based alloys in medical applications has increased substantially. An important characteristic of the medical implants is their surface quality, this being a significant constraint when machining this kind of products. The aim of this paper is to present a research conducted in order to determine and expose the influence of turning cutting parameters on the surface roughness of a CoCrWNi alloy.

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