Reduction of Vibrations due to Unbalance with Anti-Vibration Clearance Angle in High Speed Milling

2016 ◽  
Vol 836-837 ◽  
pp. 161-167
Author(s):  
Anna Thouvenin ◽  
Xin Li ◽  
Ning He ◽  
Liang Li

High speed milling is one of the most commonly used machining processes in many fields of the industry. It is regarded as a simple and fast solution to achieve a high material removal rate, which allows an important production of parts. Unbalance is a problem in any machining process but becomes a considerable problem when reaching high speed machining. The vibrations due to an unbalanced tool or tool holder can result in a poor surface quality and a damaged tool. The damping of the vibrations can be achieved with a specially designed tool showing an anti-vibration clearance angle. This paper shows the influence of the anti-vibration clearance angle by a computational model and a set of experiments to see if it can reduce or suppress the vibrations due to unbalance in high speed milling.

2010 ◽  
Vol 44-47 ◽  
pp. 335-339
Author(s):  
Ramezan Ali Mahdavinejad

The usage of lubrication in machining processes especially in high speed milling is very important. In this research, some steel samples are machined with and without cooling lubricant conditions. In these cases, the material removal rate and surface finishing of machined surfaces are analyzed. The comparison between two conditions shows that the usage of lubricant as coolant material, improves the output machining parameters significantly.


Author(s):  
Sagil James ◽  
Sharadkumar Kakadiya

Shape Memory Alloys are smart materials that tend to remember and return to its original shape when subjected to deformation. These materials find numerous applications in robotics, automotive and biomedical industries. Micromachining of SMAs is often a considerable challenge using conventional machining processes. Micro-Electrical Discharge Machining is a combination of thermal and electrical processes, which can machine any electrically conductive material at micron scale independent of its hardness. It employs dielectric medium such as hydrocarbon oils, deionized water, and kerosene. Using liquid dielectrics has adverse effects on the machined surface causing cracking, white layer deposition, and irregular surface finish. These limitations can be minimized by using a dry dielectric medium such as air or nitrogen gas. This research involves the experimental study of micromachining of Shape Memory Alloys using dry Micro-Electrical Discharge Machining process. The study considers the effect of critical process parameters including discharge voltage and discharge current on the material removal rate and the tool wear rate. A comparison study is performed between the Micro-Electrical Discharge Machining process with using the liquid as well as air as the dielectric medium. In this study, microcavities are successfully machined on shape memory alloys using dry Micro-Electrical Discharge Machining process. The study found that the dry Micro-Electrical Discharge Machining produces a comparatively better surface finish, has lower tool wear and lesser material removal rate compared to the process using the liquid as the dielectric medium. The results of this research could extend the industrial applications of Micro Electrical Discharge Machining processes.


2009 ◽  
Vol 69-70 ◽  
pp. 428-432 ◽  
Author(s):  
Qing Hua Song ◽  
Yi Wan ◽  
Shui Qing Yu ◽  
Xing Ai ◽  
J.Y. Pang

A method for predicting the stability of thin-walled workpiece milling process is described. The proposed approach takes into account the dynamic characteristics of workpiece changing with tool positions. A dedicated thin-walled workpiece representative of a typical industrial application is designed and modeled by finite element method (FEM). The workpiece frequency response function (FRF) depending on tool positions is obtained. A specific 3D stability chart (SC) for different spindle speeds and different tool positions is then elaborated by scanning the dynamic properties of workpiece along the machined direction throughout the machining process. The dynamic optimization of cutting parameters for increasing the chatter free material removal rate and surface finish is presented through considering the chatter vibration and forced vibration. The investigations are compared and verified by high speed milling experiments with flexible workpiece.


Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3749 ◽  
Author(s):  
Adel T. Abbas ◽  
Neeraj Sharma ◽  
Saqib Anwar ◽  
Faraz H. Hashmi ◽  
Muhammad Jamil ◽  
...  

Nowadays, titanium alloys are achieving a significant interest in the field of aerospace, biomedical, automobile industries especially due to their extremely high strength to weight ratio, corrosive resistance, and ability to withstand higher temperatures. However, titanium alloys are well known for their higher chemical reactive and low thermal conductive nature which, in turn, makes it more difficult to machine especially at high cutting speeds. Hence, optimization of high-speed machining responses of Ti–6Al–4V has been investigated in the present study using a hybrid approach of multi-objective optimization based on ratio analysis (MOORA) integrated with regression and particle swarm approach (PSO). This optimization approach is employed to offer a balance between achieving better surface quality with maintaining an acceptable material removal rate level. The position of global best suggested by the hybrid optimization approach was: Cutting speed 194 m/min, depth of cut of 0.1 mm, feed rate of 0.15 mm/rev, and cutting length of 120 mm. It should be stated that this solution strikes a balance between achieving lower surface roughness in terms of Ra and Rq, with reaching the highest possible material removal rate. Finally, an investigation of the tool wear mechanisms for three studied cases (i.e., surface roughness based, productivity-based, optimized case) is presented to discuss the effectiveness of each scenario from the tool wear perspective.


2013 ◽  
Vol 773-774 ◽  
pp. 348-354 ◽  
Author(s):  
Sriram Srinivasan ◽  
Lakshmikanthan Srivatsan ◽  
Rajaram Sathyanarayan ◽  
B. Vijaya Ramnath

The work of manufacturing engineers is to utilize the minimum amount of energy or resources in bringing out a product without compromising on quality. Hence, to achieve this, the engineers must figure out the optimum or the best possible method to fabricate a product. This paper uses a multi criteria decision making (MCDM) model namely Analytical Hierarchical Process (AHP) to determine the best possible machining process to achieve the optimum results for an engraving operation on gear face in an automobile industry which uses five nontraditional machining processes viz; Laser Beam Machining (LBM), Ultrasonic Machining (USM), Electric Discharge Machining (EDM), Electrochemical Machining (ECM) and Electron Beam Machining (EBM). The five criteria considered in this paper are Material Removal Rate (MRR), Surface Finish, Depth Damage, Tolerance and Toxicity. The AHP result shows that ECM is the most suitable machining process as compared to others.


Electrical discharge machining (EDM) is one of the oldest nontraditional machining processes, commonly used in automotive, aerospace and ship building industries for machining metals that have high hardness, strength and to make complicated shapes that cannot be produced by traditional machining techniques. The process is based on the thermoelectric energy between the work piece and an electrode. EDM is slow compared to conventional machining, low material removal rate, high surface roughness, high tool wear and formation of recast layer are the main disadvantages of the process. Tool wear rate, material removal rate and surface quality are important performance measures in electric discharge machining process. Numbers of ways are explored by researchers for improving and optimizing the output responses of EDM process. The paper summarizes the research on die-sinking EDM relating to the improvements in the output response.


2018 ◽  
Vol 14 (2) ◽  
Author(s):  
Deni Fajar Fitriyana ◽  
Sulardjaka Sulardjaka ◽  
Norman Iskandar ◽  
Pratama Eka P. S ◽  
Muhammad Dzulfikar

Teknologi pemesinan kecepatan tinggi (high speed machining) merupakan salah satu alternatif untuk meningkatkan produktivitas disuatu proses pemesinan. Mesin kecepatan tinggi yang digunakan di PT X adalah mesin CNC DMG Mori DMC 210U yang merupakan mesin CNC 5 axis. Namun dalam aplikasinya, mesin DMG Mori DMC 210 U ini masih belum dapat bekerja secara maksimal. Salah satu penyebabnya adalah umur pahat yang belum optimal. Tujuan dari penelitian ini adalah untuk mengetahui kondisi pemesinan yang sesuai untuk pahat routing cutter (T02) dan pahat slot drill (T31) agar mencapai umur pahat yang optimal berdasarkan data perbandingan nilai teoritis dengan nilai aktual pada mesin CNC DMC 210U. Hasil dari penelitian ini menunjukkan bahwa pada pahat routing cutter (T02), umur optimalnya adalah 300 menit sedangkan umur aktualnya adalah 196,41 menit. Pada pahat slot drill (T31), umur optimalnya adalah 350 menit sedangkan umur aktualnya adalah 330,48 menit. Maka dari itu perlu dilakukan penyesuaian kondisi pemesinan agar umur pahat menjadi optimal, dimana kondisi pemesinan yang sesuai untuk pahat routing cutter (T02) yaitu : kecepatan potong (Vc)=1225,31 mm/min, kecepatan spindle (N)= 12200 rpm , feed rate (f)=3660 mm/min , material removal rate= 351,36 cc/min, sedangkan untuk pahat slot drill (T31) yaitu : kecepatan potong (Vc)=1245,14 mm/min , kecepatan spindle (N)= 15862 rpm , feed rate (f)=4758,6 mm/min , material removal rate= 237,93 cc/min .Kata kunci: high speed machining, routing cutter, slot drill, umur pahat


This paper deals with the experimental investigation and testing on a single point cutting tool with carbide inserts and high speed steel tool. Cutting tool has to be strong enough to withstand the wear resistance. It is to be proved that carbide inserts have better performance than HSS tools on machining operation. Components with higher surface quality, higher material removal rate in less time and lower tool wear is only possible by carbide insert tools. The tool material selected for this experiment are cemented & tungsten carbide inserts along with high speed steel tool on machining medium carbon steel EN19. The complete machining process is performed on cnc lathe machine Hence the intention of this project is to minimize the surface roughness, tool wear, machining time and increasing the material removal rate. Taguchi’s L9 orthogonal array is favor for this investigation work. The result obtained in this project can be further used for optimizing the process parameters there by optimized results helps the operator to improve the quality as well as production rate.


2019 ◽  
Vol 11 (01) ◽  
pp. 26-32
Author(s):  
Angga Sateria ◽  
Eko Yudo ◽  
Zulfitriyanto Zulfitriyanto

EDM is one of the nonconventional machining processes when making workpieces with conventional machining processes is difficult. This process has been used effectively in machining hard, high-strength and high temperature materials such as high speed steel (HSS) materials. In this study, prototype of EDM machines was carried out with engine variables such as current (A), pulse on time (µs) and pulse off time (µs). The material used is high speed steel (HSS) material used in cutting tools such as turning tools and milling tools. Surface roughness and material removal rate are responses observed to determine the quality of material remaval. The quality characteristic of the surface roughness response is "smaller is better" and the quality characteristics of the material removal rate response is "larger is better. The purpose of this study is to determine the best process parameter level to achieve the required performance characteristics in the material removal process using prototype EDM machines using the gray relational analysis (GRA) method, three process parameters are selected such as current, pulse on time, and pulse off time. The taguchi 3 x 3 x 3 design is used as an experimental design.The best parameter level obtained is current 40 ampere, pulse on time 200 µs, pulse off time 20 µs.


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