scholarly journals In-situ worn geometry effect over the surface roughness propagation during micro milling process

2020 ◽  
Vol 4 (1) ◽  
pp. 1-7
Author(s):  
Nurul Farhana Mohadzir ◽  
Ainur Munira Rosli ◽  
Ahmad Shahir Jamaludin ◽  
Mohd Nizar Md Razali
Keyword(s):  
Surface Roughness ◽  
Mild Steel ◽  
Milling Process ◽  
Machining Process ◽  
Micro Milling ◽  
Micro Machining ◽  
Cnc Milling ◽  
Machined Surface ◽  
Radial Depth ◽  
Micro Tools

High-precision miniaturized components for micro-machining operations has an increasingly demand for numerous developing sectors such as medical instrumentations, electronics components, computer manufacturing, aerospace and automotive engineering. Micro-milling has known as a flexible micro machining process and the most familiar micro mechanical machining method. Due to overcome a few difficulties in micro fabrication, micro milling is picked as an alternative way as it has potential and imperative for high accuracy machining. However, micro tools have low tool life as it is unpredictably and wear quickly. Furthermore, it also has tendency to break easily due to its micro size dimension. The study observe the behaviour of micro milling worn geometry during machining and includes a non-conventional method to measure surface roughness resulted by micro milling process in machining of mild steel AISI1045. The workpiece is prepared by using CNC milling machine with facing and slotting process. Then, the mild steel AISI1045 will undergo a machining process by a 1 mm size end mill diameter with different set of parameters which are spindle speed, feed rate, radial depth and axial depth. Lastly, for the results, the surface roughness of the machined surface will be observed and the condition of tool and the measurement of wear for the tool will be investigated.

Fabrication of Micro Cylindrical Electrode with Flat End Shape and its Application in Electrochemical Micromachining

2013 ◽  
Vol 364 ◽  
pp. 244-247
Author(s):  
Yong Liu
Keyword(s):  
Electrochemical Etching ◽  
Milling Process ◽  
Machining Process ◽  
Micro Milling ◽  
Electrochemical Micromachining ◽  
Micro Machining ◽  
Metallic Materials ◽  
Cylindrical Electrode ◽  
Micro Structure ◽  
Forming Methods

Electrochemical micromachining (EMM) has become more and more important in micro machining in recent years. Micro electrode as the tool of EMM is an essential cell in the machining process. In this study, micro cylindrical electrode is fabricated by electrochemical etching firstly. Second, the flat end shape forming methods for micro cylindrical electrode is investigated. And then, micro electrodes with flat end shape fabricated above is used in electrochemical micro milling process. Finally, a 3D micro structure with three steps is machined on metallic materials by above micro cylindrical electrode with flat end shape.

Experimental Study on Milling Hardened SKD Steel Using Micro CBN Ball-End Mills

2010 ◽  
Vol 126-128 ◽  
pp. 773-778
Author(s):  
Yung Tien Liu ◽  
Neng Hsin Chiu ◽  
Yen Chun Lin ◽  
Chih Liang Lai ◽  
Yu Fu Lin ◽  
...  
Keyword(s):  
Surface Roughness ◽  
End Milling ◽  
Milling Process ◽  
Micro Milling ◽  
Depth Of Cut ◽  
Machining Accuracy ◽  
Machining Parameters ◽  
Machined Surface ◽  
Performance Function ◽  
End Mills

Micro ball-end milling process features the ability of machining complex surfaces, precision machining accuracy, and excellent machined surface roughness. However, because the diameter of a micro milling tool is very small, a rapid progress of tool wear or even tool breakage usually happens when machining a high-strength hardened mold steel using improper machining parameters. As a result, the machining cost would rise due to the quality defect in machined workpiece. In this study, to investigate how the machining parameters affect the cutting behaviors, a series of experiments using micro CBN ball-end mills with a diameter of 0.5 mm were performed to cut the SKD11 mold steel with hardness of HRC 61. The machining parameters are selected as the feeding speed (f) being 840, 960 and 1,080 mm/min, depth of cut (ap) being 30, 45, 60 μm, and spindle speed (vs) being fixed as 30,000 rpm. According to the experimental results, the measured three-axis cutting forces, flank wears, and surface roughness of machined workpiece are highly related to the cutting length. It is expected that the measured results can be used to construct a performance function of a micro ball-end tool. With referring to the performance function, the tool life can be well expected, and thus a progress in machining efficiency without tool failure can be achieved.

scholarly journals Prediction of micro milling force and surface roughness considering size-dependent vibration of micro-end mill

2021 ◽  
Author(s):  
Du Yicong ◽  
Qinghua Song ◽  
Liu Zhanqiang
Keyword(s):  
Surface Roughness ◽  
Size Effect ◽  
Surface Topography ◽  
Milling Process ◽  
Micro Milling ◽  
End Mill ◽  
Milling Force ◽  
Machined Surface ◽  
Size Dependent ◽  
Micro End Mill

Abstract When the characteristic structure size of the component is at the micron level, the internal crystal grains, grain boundaries and pore defects of the component material with the same size at the micron level cannot be ignored, so the micro-sized component will show different physical properties from the macro-sized component, which is called size effect. Since the tool diameter of micro-end mill is in the micron level, the micro-end mill will also show a significant size effect phenomenon. In addition, in micro milling process, because the surface roughness that affects the performance and service life of micro parts is mainly influenced by the vibration of micro-end mill, in order to enhance the machined surface quality, it is crucial to research the formation mechanism of surface topography in micro milling process. In this paper, a comprehensive method is proposed to predict micro-end mill vibration, micro milling force and surface roughness. At first, a size-dependent dynamic model of micro-end mill is presented based on the strain gradient elasticity theory (SGET). Secondly, considering the feedback of micro-end mill vibration, the micro milling force model is presented and solved through iterative method. Then the machined surface topography is simulated through the actual cutting edge trajectory considering the micro-end mill size-dependent vibration and material elastic recovery. The results show that the vibration of the micro-end mill will increase the micro milling force and surface roughness. In order to verify the accuracy and efficiency of the presented method, experiments are performed, and it is found that the experimental results are consistent with the predicted results.

Recent Developments in Desktop-Sized Machine Tools

2017 ◽  
Vol 261 ◽  
pp. 425-431 ◽  
Author(s):  
Jan C. Aurich ◽  
Christopher Müller ◽  
Martin Bohley ◽  
Peter Arrabiyeh ◽  
Benjamin Kirsch
Keyword(s):  
Surface Roughness ◽  
Machine Tools ◽  
Micro Milling ◽  
Bottom Surface ◽  
Manufacturing Processes ◽  
Micro Machining ◽  
Machining Quality ◽  
Recent Developments ◽  
Micro Structures ◽  
Micro Tools

The miniaturization of components and the functionalization via micro structures demands for flexible and economic manufacturing processes. Micro machining, i.e. micro milling and micro grinding can meet these requirements. In this paper, desktop-sized machine tools and their components that were developed at our institute are presented. With those machine tools, micro tools can be machined and used in one clamping, allowing for increased machining quality. Grooves milled with such machine tools achieve a bottom surface roughness below 10 nanometer.

Surface Roughness and Cutting Force Components Evaluation in Hard Turning by Differently Shaped Cutting Tools

2016 ◽  
Vol 862 ◽  
pp. 26-32 ◽  
Author(s):  
Michaela Samardžiová
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Hard Turning ◽  
Cutting Tool ◽  
Single Point ◽  
Machining Process ◽  
Tool Geometry ◽  
Machined Surface ◽  
Cutting Force Components ◽  
Force Components

There is a difference in machining by the cutting tool with defined geometry and undefined geometry. That is one of the reasons of implementation of hard turning into the machining process. In current manufacturing processes is hard turning many times used as a fine finish operation. It has many advantages – machining by single point cutting tool, high productivity, flexibility, ability to produce parts with complex shapes at one clamping. Very important is to solve machined surface quality. There is a possibility to use wiper geometry in hard turning process to achieve 3 – 4 times lower surface roughness values. Cutting parameters influence cutting process as well as cutting tool geometry. It is necessary to take into consideration cutting force components as well. Issue of the use of wiper geometry has been still insufficiently researched.

Study on Machining Mechanism of Glass Using Discrete Element Method

2014 ◽  
Vol 577 ◽  
pp. 108-111 ◽  
Author(s):  
Ying Qiu ◽  
Mei Lin Gu ◽  
Feng Guang Zhang ◽  
Zhi Wei
Keyword(s):  
Discrete Element Method ◽  
Element Model ◽  
Discrete Element ◽  
Rake Angle ◽  
Milling Process ◽  
Micro Milling ◽  
Discrete Element Model ◽  
Machined Surface ◽  
Damage Depth ◽  
Element Method

The discrete element method (DEM) is applied to glass micromachining in this study. By three standard tests the discrete element model is established to match the main mechanical properties of glass. Then, indentating, cutting, micro milling process are simulated. Results show that the vertical damage depth is prevented from reaching the final machined surface in cutting process. Tool rake angle is the most remarkable factor influencing on the chip deformation and cutting force. The final machined surface is determined by the minimum cutting thickness per edge. Different cutting thickness, cutter shape and spindle speed largely effect on the mechanism of glass.

Experimental investigation of the influence of cutting parameters on surface quality and on the special characteristics of micro-milled surfaces of hardened steels

2021 ◽  
pp. 095440622110130
Author(s):  
Barnabás Zoltán Balázs ◽  
Márton Takács
Keyword(s):  
Surface Quality ◽  
Surface Profile ◽  
Cutting Parameters ◽  
Relevant Information ◽  
Milling Process ◽  
Micro Milling ◽  
Machined Surface ◽  
Analysis Of Dynamics ◽  
Five Axis ◽  
Coated Carbide

Micro-milling is one of the most essential technologies to produce micro components, but due to the size effect, it has many special characteristics and challenges. The process can be characterised by strong vibrations, relatively large run-out and tool deformation, which directly affects the quality of the machined surface. This paper deals with a detailed investigation of the influence of cutting parameters on surface roughness and on the special characteristics of micro-milled surfaces. Several systematic series of experiments were carried out and analysed in detail. A five-axis micromachining centre and a two fluted, coated carbide micro-milling tool with a diameter of 500 µm were used for the tests. The experiments were conducted on AISI H13 hot-work tool steel and Böhler M303 martensitic corrosion resistance steel with a hardness of 50 HRC in order to gain relevant information of machining characteristics of potential materials of micro-injection moulding tools. The effect of the cutting parameters on the surface quality and on the ratio of Rz/ Ra was investigated in a comprehensive cutting parameter range. ANOVA was used for the statistical evaluation. A novel method is presented, which allows a detailed analysis of the surface profile and repetitions, and identify the frequencies that create the characteristic profile of the surface. The procedure establishes a connection between the frequencies obtained during the analysis of dynamics (forces, vibrations) of the micro-milling process and the characterising repetitions and frequencies of the surface.

Evaluation of Surface Integrity in Electrochemical Micromachining of A286 Super alloy

2021 ◽  
Author(s):  
Rajkeerthi E ◽  
Hariharan P
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Surface Integrity ◽  
Research Work ◽  
Machining Process ◽  
Electrochemical Micromachining ◽  
Dissolution Mechanism ◽  
Machined Surface ◽  
Micro Holes ◽  
Super Alloy

Abstract Surface integrity of micro components is a major concern particularly in manufacturing industries as most geometry of the products must meet out necessary surface quality requirements. Advanced machining process like electrochemical micro machining possess the capabilities to machine micro parts with best surface properties exempting them from secondary operations. In this research work, different electrolytes have been employed for producing micro holes in A286 super alloy material to achieve the best surface quality and the measurement of surface roughness and surface integrity to evaluate the machined surface is carried out. The machined micro hole provides detailed information on the geometrical features. A study of parametric analysis meant for controlling surface roughness and improvement of surface integrity has been made to find out the suitable parameters for machining. The suitability of various electrolytes with their dissolution mechanism and the influence of various electrolytes have been thoroughly studied. Among the utilized electrolytes, EG + NaNO3 electrolyte provided the best results in terms of overcut and average surface roughness.

An accurate instantaneous uncut chip thickness model combining runout effect in micro-milling using cutters with the non-uniform helix and pitch angles

2019 ◽  
Vol 234 (5) ◽  
pp. 859-870 ◽  
Author(s):  
Qiang Guo ◽  
Yan Jiang ◽  
Zhibo Yang ◽  
Fei Yan
Keyword(s):  
Tool Path ◽  
Chip Thickness ◽  
Milling Process ◽  
Machining Process ◽  
Micro Milling ◽  
Cutter Runout ◽  
Model Combining ◽  
Key Factor ◽  
Cutting Point ◽  
Instantaneous Uncut Chip Thickness

As a key factor, the accuracy of the instantaneous undeformed thickness model determines the force-predicting precision and further affects workpiece machining precision in the micro-milling process. The runout with five parameters affects the machining process more significantly compared with macro-milling. Furthermore, modern industry uses cutters with non-uniform pitch and helix angles more and more common for their excellent properties. In this article, an instantaneous undeformed thickness model is presented regarding cutter runout, variable pitch, and helix angles in the micro-milling process. The cutter edge with the cutter runout effect is modeled. Then, the intersecting ellipse between the plane vertical to the spindle axis and the cutter surface which is a cylinder can be gained. Based on this, the points, which are used to remove the material, on the ellipse as well as cutter edges are calculated. The true trochoid trajectory for each cutting point along the tool path is built. Finally, the instantaneous undeformed thickness values are computed using a numerical algorithm. In addition, this article analyzes runout parameters’ effects on the instantaneous undeformed thickness values. After that, helix and pitch angles’ effects on the instantaneous undeformed thickness are studied. Ultimately, the last section verifies the correctness and validity of the instantaneous undeformed thickness model based on the experiment conducted in the literature.

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