scholarly journals Optimization of CFRP Micro Drilling Parameter using 2-Level Factorial Method Towards Thrust Force

Carbon Fiber Reinforced Polymer (CFRP) is extensively used in aircraft and automotive industries due to it exceptional material properties such as high strength to weight ratio and corrosion resistance. Nevertheless, micro drilling process of CFRP material poses various challenge as it has irregular material properties along the structure. High cutting force which lead to poor hole quality is one of the issues that always occur when drilling this material. Hence, the understanding on the relationship between process parameter and material behavior is vital to achieve optimum performance of machining process. The experiment was carried out using 2-level factorial design with variable spindle speed range of 8,000 – 12,000 rpm and feed rate range of 0.01-0.015 mm/rev. Micro drill bit with diameter of 0.9 mm was used and new fresh drill were used for every run to avoid tool wear effect. As a result, lower thrust force of 6.3742 N is obtained from the combination of spindle speed 10k rpm and feed rate 0.0125 N. Therefore, it can be concluded that, optimum parameter falls between the range of 8,000 – 12,000 rpm of spindle speed and 0.01-0.015 mm/rev of feed rate. Validation of the optimum parameter suggested from 2-level factorial which are 8,000 rpm and 0.01 mm/rev is executed. The final result obtained shows 4.5% of error from targeted value and this result is absolutely acceptable and portray the reliability of the experiment.

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 854
Author(s):  
Muhammad Aamir ◽  
Khaled Giasin ◽  
Majid Tolouei-Rad ◽  
Israr Ud Din ◽  
Muhammad Imran Hanif ◽  
...  

Drilling is an important machining process in various manufacturing industries. High-quality holes are possible with the proper selection of tools and cutting parameters. This study investigates the effect of spindle speed, feed rate, and drill diameter on the generated thrust force, the formation of chips, post-machining tool condition, and hole quality. The hole surface defects and the top and bottom edge conditions were also investigated using scan electron microscopy. The drilling tests were carried out on AA2024-T3 alloy under a dry drilling environment using 6 and 10 mm uncoated carbide tools. Analysis of Variance was employed to further evaluate the influence of the input parameters on the analysed outputs. The results show that the thrust force was highly influenced by feed rate and drill size. The high spindle speed resulted in higher surface roughness, while the increase in the feed rate produced more burrs around the edges of the holes. Additionally, the burrs formed at the exit side of holes were larger than those formed at the entry side. The high drill size resulted in greater chip thickness and an increased built-up edge on the cutting tools.


2020 ◽  
Vol 402 ◽  
pp. 125-130
Author(s):  
Muhammad Tadjuddin ◽  
Suhaeri ◽  
Muhammad Dirhamsyah ◽  
Aulia Udink ◽  
Fatur Rahmatsyah

The micro-drill is one of the manufacturing processes that is developing, especially in the electronics, aerospace, pharmaceutical, and automotive industries. This paper describes the results of the high-speed microdrill process in stainless steel. The drilling process is used to make the micro screen. The cutting tool material is tungsten carbide with a diameter of 0.2 mm. Drilling holes arranged in a honeycomb configuration. The machining parameters used are spindle speed of 20,000 rpm, 22,000 rpm, 24,000 rpm, and feed rate of 1 mm/min, 1.5 mm/min, 2 mm/min. Micro-drilling holes are visually analyzed using a Scanning Electron Microscope (SEM) to measure the accuracy of the hole dimensions. The results of the machining process found that the most significant deviation of the hole dimension size with a value of 0.276 mm occurred at a spindle speed of 20,000 rpm with a feed of 1 mm/min. While the deviation of the smallest hole size with a value of 0.2019 mm occurred at a spindle speed of 24,000 rpm with a feed of 2 mm/min, these results conclude that the accuracy of the hole dimensions will increase in proportion to the increase in spindle speed and feeding.


2017 ◽  
Vol 748 ◽  
pp. 254-258
Author(s):  
Chang Yi Liu ◽  
Bai Shou Zhang ◽  
Suman Shrestha

Drilling experiments of titanium alloy Ti6Al4V were conducted. Taking the speed and feed as the process variables, a set of experimental cutting forces are obtained and compared. From the experimental results it is concluded that within the experimental extent the thrust force and torque of drilling process rises with the feed rate. The lower spindle speed resulted in the greater amount of thrust. Feed rates have greater influence on the thrust force than the spindle speed. The combination of greater feed rate and lower spindle speed results in the maximum amount of thrust. However, combination of greater feed rate and spindle speed resulted in maximum amount of torque.


2011 ◽  
Vol 188 ◽  
pp. 429-434 ◽  
Author(s):  
L.P. Yang ◽  
Li Xin Huang ◽  
Cheng Yong Wang ◽  
L.J. Zheng ◽  
Ping Ma ◽  
...  

Supported holes of Printed circuit board (PCB) are drilled with two different drill bits. Drilling force (thrust force and torque) and chip morphology are examined at different cutting parameters, and the effects of the two drills are discussed. The results indicate that the drilling force and chip morphology are affected by the feed rate, spindle speed and drill shape. Thrust force increases with the increasing feed rate, and decreases with the increasing spindle speed. Optimization of drill geometry can reduce the thrust force significantly, and is effective in chip breaking which can improve the chip evacuation during the drilling process.


2019 ◽  
Vol 9 (01) ◽  
pp. 1-5
Author(s):  
Angga Sateria

Glass fiber reinforced polymer (GFRP)-stainless steel stacks used in the aircraft structural components. The assembly process of this components requires mechanical joining using bolt and nut. The drilling process is commonly used for producing hole to position the bolt correctly. Thrust force and torque are responses that used to evaluate the performance of drilling process. The quality characteristic of these responses are “smaller-is-better.” The aim of this experiment is to identify the combination of process parameters for achieving required multiple performance characteristics in drilling process of GFRP-stainless steel stacks materials. The three important process parameters, i.e., point angle, spindle speed, and feed rate were used as input parameters. Point angle was set at two different levels, whilethe other two were set at three different levels. Hence, a 2 x 3 x 3 full factorial was used as designexperiments. The experiments were replicated two times. The optimization was conducted by using genetic algorithm method. The minimum thrust force and torque could be obtained by using point angle, spindle speed and feed rate of 118o, 2383 rpm, 62 mm/min respectively.


2010 ◽  
Vol 638-642 ◽  
pp. 927-932 ◽  
Author(s):  
M.A. Azmir ◽  
Praveena Nair Sivasankaran ◽  
Z. Hamedon

This thesis deals with carbon fiber reinforced plastics (CFRP) composites, an advanced material which is widely used in manufacturing aircrafts because of their unique mechanical and physical properties. The research mainly involved drilling of CFRP. This study is focused on analyzing the thrust force and delamination against drilling parameters namely feed rate, spindle speed and type of tool materials. Also, the optimal parameters were chosen using an optimization method called D optimal. It was observed that the higher the feed rate and spindle speed employed, the higher the thrust force and delamination occur. The split point fibre (SPF) drill gave the lowest values of thrust force and delamination. Based on the optimal parameters, a verification test was conducted and the prediction error was 2.3% and 5.6% for thrust force and delamination respectively. This shows, that the optimal parameters obtained is reliable as it could improve the process considerably. The results of this study could be used as a reference for further research and studies on drilling of CFRP.


2015 ◽  
Vol 766-767 ◽  
pp. 831-836 ◽  
Author(s):  
T.N. Valarmathi ◽  
K. Palanikumar ◽  
S. Sekar

Medium density fiberboard wood composite panels are preferred for many domestic and industrial applications over the natural wood because of their high-quality properties. The aesthetic appearance of wood composites makes them suitable for interior and exterior construction works. Among various machining process, drilling is the most frequently used machining operation in the furniture industry in assembly of panel products. During drilling process the drill exhibits cutting forces such as thrust force and torque. The surface quality of the drilled holes are mainly affected by the cutting forces developed during drilling process which causes surface roughness, delamination like damages which leads to the rejection of the final product. Hence the reduction of the drilling defects, the control of the cutting forces is very much essential. The drilling parameters play an important role in controlling the cutting forces. The objective of this work is to study the influence of input control parameters such as spindle speed, feed rate and point angle on surface roughness in drilling of MDF panels to obtain the optimal cutting conditions. In the present study the drilling experiments are conducted using Taguchi design of experiments on wood composite panels with high speed steel (HSS) twist drills with different point angles on vertical machining center using at dry condition. Three levels and three factors are considered. Taguchi L27 orthogonal array is used. Response surface methodology is used to develop a mathematical model to predict the influence of input control parameters on cutting forces. Analysis of variance is used to check the adequacy of the model. Surface roughness is increased with an increase of feed rate and drill point angle and decreased with an increase in the spindle speed. It is revealed that high spindle speed with low feed rate and smaller point angle combination gives better results in drilling of wood composite panels.


2013 ◽  
Vol 278-280 ◽  
pp. 389-392
Author(s):  
Mohammad Yeakub Ali ◽  
A. R. Mohamed ◽  
Nor Fadila ◽  
Noor Hannah

This paper discusses burr in microdrilling that affect forms and functions of parts. The effects of microdrilling parameters on burr length and width are identified. The experiment was conducted using Mikrotools DT110 machine with one millimetre diameter of HSS on copper workpiece. Burr heights in terms of burr length and burr width were measured by using scanning electron microscope. The data was analyzed using Taguchi method to find the optimum micro-drilling process parameter for minimizing the burr height. The relationship among spindle speed, feed rate and burr has been developed. It is found that feed rate is the most influential factors on the burr height. The desirability of getting the minimum burr height is 72% and the optimum parameters are 30000 rpm spindle speed and 0.2 mm/min feed rate.


2014 ◽  
Vol 564 ◽  
pp. 501-506 ◽  
Author(s):  
Mohd Azuwan Maoinser ◽  
Faiz Ahmad ◽  
Safian Shariff ◽  
Tze Keong Woo

Drill point angle of twist drill has a significant effect on thrust force and delamination factor on drilled holes in fiber reinforced polymer (FRP) composites. In this study, three drill point angle of twist drill; 85°, 118° and 135° were used to drill holes in hybrid fiber reinforced polymeric composite (HFRP). HFRP composites were fabricated using vacuum infusion molding (VIM) technique. The test samples were cured at 90°C for two hours. In drilling process various drill point angle and feed rate were employed to investigate the effect of both parameters on thrust force and delamination factor when drilling the HFRP composite. The results showed that small drill point angle and low feed rate can reduce the thrust force leading to the reduction of damage factor at the holes entrance and exit.


2013 ◽  
Vol 763 ◽  
pp. 29-49 ◽  
Author(s):  
A. Prabukarthi ◽  
V. Krishnaraj ◽  
M. Senthil Kumar

Titanium alloys present superior properties like resistance to corrosion, high strength to weight ratio etc, but possess poor machinability. Titanium alloy Ti-6Al-4V is the most commonly used titanium alloy in aerospace and medical device industries. Titanium and its alloys are notorious for their poor thermal properties and are classified as difficult-to-machine materials. Drilling is an important machining process since it is involved in nearly all titanium applications. It is desirable to develop optimized drilling processes for Ti and improve the hole characteristics such as hole diameter, circularity and exit burr of currently available processes. Due to the low machinability of the alloys under study, selecting the machining conditions and parameters is crucial. The range of spindle speed and feed rate, which provide a satisfactory tool life, is very limited. The hole quality (hole diameter and circularity), thrust force, torque and exit burr were evaluated at various spindle speeds, feed rates combinations. The optimized parameter is chosen using the multi-objective weighted sum optimization technique.


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