Surface Textured Drill Tools—An Effective Approach for Minimizing Chip Evacuation Force and Burr Formation During High Aspect Ratio Machining of Titanium Alloy

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
S. Niketh ◽  
G. L. Samuel
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Sliding Friction ◽  
Thrust Force ◽  
Research Work ◽  
Machining Process ◽  
Cutting Fluid ◽  
Burr Formation ◽  
Burr Height ◽  
Drill Tool

Abstract The real challenge pertaining to high aspect ratio drilling is the rapid increase in chip evacuation force due to the chip clogging phenomenon occurring at higher drilling depths. The clogged chips will further impede the reachability of cutting fluid at the machining zone leading to the tool temperature buildup. This will eventually result in the catastrophic failure of the tool. Hence, in the present work, an attempt has been made to minimize the chip evacuation force by functionalizing the drill tool surfaces based on the laser microtexturing principle. Microscale textures in the form of circular dimples were created on the flute and margin side of the drill tool with an objective to control the sliding friction, thereby minimizing the chip clogging effect. The effectiveness of the functionalized drill tools were assessed mainly based on the variation in thrust force and torque. Drilling experiments showed a net reduction of 17.18% in thrust force and 26.98% in torque while machining Ti–6Al–4V using the flute and margin textured tool, which justified the effectiveness of micro scale textures in minimizing the chip evacuation forces. The experimental analysis was further extended in terms of burr height evaluation, where FMT tools were found to be highly effective in burr height reduction (1.29 mm), showing a net reduction of 54.26% when compared with the non-textured tool. The outcomes from this research work will be highly beneficial for the manufacturing industries including aerospace, automobile, and spacecraft as high aspect ratio drilling of titanium alloys are still categorized to be the most challenging machining process owing to its lower thermal conductive property.

An investigation on formation of burrs during milling of aluminium alloy under wet condition

2020 ◽  
pp. 095440542097201
Author(s):  
Raj Sekhar Mandal ◽  
Santanu Das ◽  
Partha Pratim Saha
Keyword(s):  
Suitable Condition ◽  
Face Milling ◽  
Machining Process ◽  
Burr Formation ◽  
Depth Of Cut ◽  
Burr Height ◽  
Cutting Velocity ◽  
Wet Condition ◽  
Exit Edge ◽  
Coated Carbide

Undesirable burrs are created out of a machining process. The objective of the present work is to explore the suitable condition to obtain no burr, or negligible burr, around the edge of a machined product at wet condition. Face milling experiments have been carried out on blocks made of aluminum alloy (Alloy-4600M) with a single, coated-carbide inserted cutter for observing the nature of burr formation. Depth of cut has been maintained constant at 3 mm for all sets of experiments. In each experiment set, three cutting velocities (170 m/min, 237 m/min and 339 m/min) and three in-plane exit angles of 30°, 60° and 90° are provided at three different feeds of 0.08 mm/tooth, 0.1 mm/tooth and 0.12 mm/tooth. First set of experiments are done without any exit edge bevel. Similar sets of experiments are carried out with 15° and 30° exit edge bevel angles to find out the condition for minimum burr. The bevel is made of a height of 3 mm. In the present experimental investigation, a minimum burr height of as low as 3 micron is obtained at an in-plane exit angle of 30° and exit edge bevel angle of 15° under the machining condition of 339 m/min cutting velocity and 0.1 mm/tooth feed.

Investigation on micro-milling of micro-grooves with high aspect ratio and laser deburring

2019 ◽  
Vol 234 (5) ◽  
pp. 871-880 ◽  
Author(s):  
Yinfei Yang ◽  
Jinjin Han ◽  
Xiuqing Hao ◽  
Liang Li ◽  
Ning He
Keyword(s):  
Aspect Ratio ◽  
Tool Wear ◽  
Surface Quality ◽  
High Aspect Ratio ◽  
High Conductivity ◽  
Cutting Fluid ◽  
Micro Milling ◽  
Free Alcohol ◽  
Processing Efficiency ◽  
Machined Surface

High aspect ratio micro-grooves are critical structures in the micro-electromechanical system. However, problems like rapid tool wear, low processing efficiency, and inferior machined quality in micro-milling of high aspect ratio micro-grooves by length–diameter ratio tools are particularly significant. In this work, a combined micro-milling method based on water-free alcohol as the cutting fluid and laser deburring is proposed to investigate the high aspect ratio micro-groove generation of oxygen-free high-conductivity copper TU1. Parametric experiments and high aspect ratio micro-groove experiments were conducted to investigate the surface quality, cutting forces, and tool wear. The water-free alcohol was employed to improve the tool life and machined surface quality. In the case of the oxygen-free high-conductivity copper TU1 material, a satisfactory high aspect ratio micro-groove (groove-width = 0.2 μm and aspect ratio = 2.5) with a nanoscale surface roughness ( Ra = 68 nm) was obtained under the preferred machining conditions. Furthermore, the deburring process of the high aspect ratio micro-groove by the laser technology was conducted to achieve ideal machined quality of the top surfaces.

Burr Size Minimization When Drilling 6061-T6 Aluminum Alloy

2012 ◽  
Author(s):  
Y. Zedan ◽  
S. A. Niknam ◽  
A. Djebara ◽  
V. Songmene
Keyword(s):  
Process Parameters ◽  
Cutting Speed ◽  
Cutting Conditions ◽  
Cutting Fluid ◽  
Burr Formation ◽  
Formation Mechanisms ◽  
Regression Equations ◽  
Taguchi Optimization ◽  
Burr Height ◽  
Burr Size

The burr formation mechanisms strongly depend on the machining methods as well as cutting conditions. Cutting fluids play significant roles in machining, including reduction of friction and temperature. Using a cutting fluid, however, degrades the quality of the environment and increases machining costs. In the present work, initially the effects of cutting fluid application (dry, mist and flood) and their interaction with cutting parameters on the burr size during drilling of 6061-T6 aluminum alloys were investigated using multi-level full factorial design. Second-order non-linear mathematical models were developed to predict burr height for various lubrication modes. The accuracy of the regression equations formulated to predict burr height when using different lubrication modes has been verified through carrying out random experiments in the range of variation of these variables. A procedure was developed to minimize burr size for drilling holes by presenting the optimal levels of process parameters. Taguchi optimization method based on L9 orthogonal array design of experiment was then used which has shown very accurate process parameters selection that leads to minimum burr height. According to experimental study, it was observed that dry and mist drilling can produce parts with quality comparable with those obtained in wet drilling when using the optimal cutting conditions. In addition, increase in cutting speed and feed rate exhibits a decrease in burr size.

The Effect of Cutting Force Vibration on Machining Quality for Reaming ZL102 Alloy with PCD Step Reamer

2018 ◽  
Vol 764 ◽  
pp. 279-290
Author(s):  
X.D. Wang ◽  
W.L. Ge ◽  
Y.G. Wang
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Cutting Forces ◽  
Thrust Force ◽  
Maximum Amplitude ◽  
Spindle Speed ◽  
Machining Process ◽  
Cutting Fluid ◽  
Hole Quality ◽  
Force Vibration

The characteristics of cutting forces vibration and its effects to the hole quality in reaming aluminum cast alloy using a poly-crystalline diamond (PCD) step reamer in dry and wet conditions were studied. First, centrifugal force vibration model of the PCD step reamer during machining process was established and through the analysis of the model, it can be concluded that the maximum amplitude of the vibration is positively related to the angular velocity of the reamer. Then, thrust force and cutting torque were measured by a Kistler Dynamometer during reaming process and these vibration frequency and amplitude were analyzed by fast Fourier transformation (FFT). Hole quality was evaluated by hole diameter and surface roughness. Results show that, as the spindle speed increases, the stability of thrust force and cutting torque deteriorates gradually, and there was a severe vibration in the cutting force and the surface roughness when the spindle speed reached 10000 rpm in wet and 7000 rpm in dry cutting conditions. Compared the variation of hole surface roughness and vibration characteristic of cutting forces, it can be observed that the trends are very consistent, the surface roughness deteriorates when cutting forces become unstable. Therefore,the cutting forces stability was an important factor that influence the hole quality. Cutting fluid has a positive effect to stabilize the reaming process and was beneficial to improve the hole quality.

The Accuracy of Micro-molds Produced by a UV Laser Induced Polymerization

1994 ◽  
Vol 116 (3) ◽  
pp. 370-376 ◽  
Author(s):  
K. Yamaguchi ◽  
T. Nakamoto ◽  
P. A. Abbay ◽  
S. Mibu
Keyword(s):  
Thin Films ◽  
Aspect Ratio ◽  
Laser Beam ◽  
High Aspect Ratio ◽  
Research Work ◽  
Practical Method ◽  
High Accuracy ◽  
Uv Laser ◽  
Ultraviolet Laser ◽  
Absorption Of Light

This research work deals with the development of a simple and practical method for manufacturing metallic micromachine parts on the order of 0.01–1.0 mm in size. In this method, an ultraviolet laser beam is irradiated onto the surface of a liquid photopolymer material through a mask. The irradiated pattern is then developed to produce a solidified photopolymer mold. Finally, the metallic part is made by an electroforming process. This paper deals with the first process, the making of the photopolymer mold. At first, the accuracy of the mold is estimated by applying the theories of diffraction and absorption of light. Next, the accuracy is examined experimentally. The results show an accuracy of ± 1 μm can be obtained when a proximity transfer of 10 μm between the mask and the photopolymer surface is used. By stacking thin films, thick and high aspect ratio molds with a reasonably high accuracy are made.

High Aspect Ratio Machining of Carbon Fiber Reinforced Plastics by Electrical Discharge Machining Process

2020 ◽  
Author(s):  
Cibi Makudapathy ◽  
Murali Sundaram
Keyword(s):  
Carbon Fiber ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Machining Process ◽  
Fiber Reinforced ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics

Abstract Micromachining of Carbon Fiber Reinforced Plastics (CFRPs) is essential for numerous applications in several industries such as aerospace, automotive, defense, shipping, sporting goods, and biomedical industries. The major challenge in machining CFRP by electrical discharge machining (EDM) is due to the non-conductivity of epoxy material which is used as a binder for manufacturing these CRFPs. This study attempts a novel, yet simple approach to ensure the conductivity of the work piece through the entire machining process. Experiments were carried out in this work to assess the feasibility of machining high aspect ratio micro-holes in CFRP by micro EDM. The effect of process parameters such as voltage and feed-rate on the hole quality was studied. Using optimal process conditions, micro hole of 2500 µm deep with an aspect ratio of over 11 was achieved.

Analysis of Surface Texture of High Aspect Ratio Blind Micro Holes on Titanium Alloy (Ti-6Al-4V) in Micro Electrical Discharge Drilling

2017 ◽  
Vol 261 ◽  
pp. 151-158 ◽  
Author(s):  
Swapan Barman ◽  
Asit Baran Puri ◽  
Nagahanumaiah
Keyword(s):  
Titanium Alloy ◽  
Aspect Ratio ◽  
Surface Integrity ◽  
High Aspect Ratio ◽  
Electrical Discharge ◽  
Desirability Function ◽  
Machining Process ◽  
Machining Parameters ◽  
Micro Holes ◽  
Electrical Discharge Drilling

Efficiency of any machining process depends on the effectiveness of final outcomes. Surface integrity plays an important role in functional performance of a part or component. Traditionally, surface roughness is considered to be the principal parameter to assess the surface integrity of a machined surface. In this paper, the influences of machining parameters like gap voltage, capacitance and depth of hole on the surface finish parameters like Ra and Sa of micro holes have been studied in micro electrical discharge drilling. The high aspect ratio blind micro holes were drilled on titanium alloy (Ti-6Al-4V) with cylindrical tungsten tool electrodes. The experimentation was carried out adopting a full factorial design (33). The simultaneous effects of machining parameters on responses were analysed using response surface methodology. Multiple linear regression models were developed for responses to obtain the correlation between machining parameters and machining outputs. Multi-objective optimization has been performed with the aid of the desirability function approach.

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