Preliminary Study of Ultrasonic Assisted Underwater Laser Micromachining of Silicon

2016 ◽  
Vol 835 ◽  
pp. 139-143
Author(s):  
Wisan Charee ◽  
Viboon Tangwarodomnukun ◽  
Chaiya Dumkum

The disturbances of vapor bubble to a laser beam in the underwater laser machinig process importantly limits the material removal rate and cut quality obtained. This issue is more essential for the laser micromachining process that a precise and small trench cut is highly needed. In this study, the ultrasound was used to energize and break up the bubble while the laser beam was performing a cut in water. Silicon was used as a work sample in this study as its significant usage in many micro-components. An ultrasonic transducer was located nearby the workpiece in an attempt to vibrate surrounding water. The results revealed that an increase in ultrasonic power increased the width and depth of cut channel. In addition, the workpiece surface obtained after the ablation was clean as similar to that performed by the ultrasonic cleaning. This combination of laser machining and ultrasonic cleaning processes can be another effective approach to cut thermal sensitive materials and also small components whose thermal damage and deposition of cut debris can be harmful to their functionality after laser ablation.

2010 ◽  
Vol 443 ◽  
pp. 693-698 ◽  
Author(s):  
Viboon Tangwarodomnukun ◽  
Jun Wang ◽  
Philip Mathew

Laser micromachining has been widely used for decades to fabricate the micro- and submicro-component structures. However, thermal and physical damages are crucial issues associated with the process. Underwater laser ablation has been developed as a damage-free micro-ablation technique. In this paper, a comparison of the conventional dry and underwater laser micromachining of silicon is presented. It shows that the heat affected zone (HAZ) can be reduced significantly in the underwater laser process, though the material removal rate is reduced due to the energy loss by the water layer. The effects of pulse frequency, traverse speed and laser energy on the obtained kerf width, HAZ and cut surface quality are also analyzed and discussed.


Author(s):  
Amritpal Singh ◽  
Rakesh Kumar

In the present study, Experimental investigation of the effects of various cutting parameters on the response parameters in the hard turning of EN36 steel under the dry cutting condition is done. The input control parameters selected for the present work was the cutting speed, feed and depth of cut. The objective of the present work is to minimize the surface roughness to obtain better surface finish and maximization of material removal rate for better productivity. The design of experiments was done with the help of Taguchi L9 orthogonal array. Analysis of variance (ANOVA) was used to find out the significance of the input parameters on the response parameters. Percentage contribution for each control parameter was calculated using ANOVA with 95 % confidence value. From results, it was observed that feed is the most significant factor for surface roughness and the depth of cut is the most significant control parameter for Material removal rate.


Author(s):  
A. Pandey ◽  
R. Kumar ◽  
A. K. Sahoo ◽  
A. Paul ◽  
A. Panda

The current research presents an overall performance-based analysis of Trihexyltetradecylphosphonium Chloride [[CH3(CH2)5]P(Cl)(CH2)13CH3] ionic fluid mixed with organic coconut oil (OCO) during turning of hardened D2 steel. The application of cutting fluid on the cutting interface was performed through Minimum Quantity Lubrication (MQL) approach keeping an eye on the detrimental consequences of conventional flood cooling. PVD coated (TiN/TiCN/TiN) cermet tool was employed in the current experimental work. Taguchi’s L9 orthogonal array and TOPSIS are executed to analysis the influences, significance and optimum parameter settings for predefined process parameters. The prime objective of the current work is to analyze the influence of OCO based Trihexyltetradecylphosphonium Chloride ionic fluid on flank wear, surface roughness, material removal rate, and chip morphology. Better quality of finish (Ra = 0.2 to 1.82 µm) was found with 1% weight fraction but it is not sufficient to control the wear growth. Abrasion, chipping, groove wear, and catastrophic tool tip breakage are recognized as foremost tool failure mechanisms. The significance of responses have been studied with the help of probability plots, main effect plots, contour plots, and surface plots and the correlation between the input and output parameters have been analyzed using regression model. Feed rate and depth of cut are equally influenced (48.98%) the surface finish while cutting speed attributed the strongest influence (90.1%). The material removal rate is strongly prejudiced by cutting speed (69.39 %) followed by feed rate (28.94%) whereas chip reduction coefficient is strongly influenced through the depth of cut (63.4%) succeeded by feed (28.8%). TOPSIS significantly optimized the responses with 67.1 % gain in closeness coefficient.


2020 ◽  
Vol 38 (10A) ◽  
pp. 1489-1503
Author(s):  
Marwa Q. Ibraheem

In this present work use a genetic algorithm for the selection of cutting conditions in milling operation such as cutting speed, feed and depth of cut to investigate the optimal value and the effects of it on the material removal rate and tool wear. The material selected for this work was Ti-6Al-4V Alloy using H13A carbide as a cutting tool. Two objective functions have been adopted gives minimum tool wear and maximum material removal rate that is simultaneously optimized. Finally, it does conclude from the results that the optimal value of cutting speed is (1992.601m/min), depth of cut is (1.55mm) and feed is (148.203mm/rev) for the present work.


2018 ◽  
Vol 49 (2) ◽  
pp. 62-81 ◽  
Author(s):  
Shailendra Kumar ◽  
Bhagat Singh

Tool chatter is an unavoidable phenomenon encountered in machining processes. Acquired raw chatter signals are contaminated with various types of ambient noises. Signal processing is an efficient technique to explore chatter as it eliminates unwanted background noise present in the raw signal. In this study, experimentally recorded raw chatter signals have been denoised using wavelet transform in order to eliminate the unwanted noise inclusions. Moreover, effect of machining parameters such as depth of cut ( d), feed rate ( f) and spindle speed ( N) on chatter severity and metal removal rate has been ascertained experimentally. Furthermore, in order to quantify the chatter severity, a new parameter called chatter index has been evaluated considering aforesaid denoised signals. A set of 15 experimental runs have been performed using Box–Behnken design of experiment. These experimental observations have been used to develop mathematical models for chatter index and metal removal rate considering response surface methodology. In order to check the statistical significance of control parameters, analysis of variance has been performed. Furthermore, more experiments are conducted and these results are compared with the theoretical ones in order to validate the developed response surface methodology model.


Author(s):  
Rajesh Kumar Bhushan

Optimization in turning means determination of the optimal set of the machining parameters to satisfy the objectives within the operational constraints. These objectives may be the minimum tool wear, the maximum metal removal rate (MRR), or any weighted combination of both. The main machining parameters which are considered as variables of the optimization are the cutting speed, feed rate, depth of cut, and nose radius. The optimum set of these four input parameters is determined for a particular job-tool combination of 7075Al alloy-15 wt. % SiC (20–40 μm) composite and tungsten carbide tool during a single-pass turning which minimizes the tool wear and maximizes the metal removal rate. The regression models, developed for the minimum tool wear and the maximum MRR were used for finding the multiresponse optimization solutions. To obtain a trade-off between the tool wear and MRR the, a method for simultaneous optimization of the multiple responses based on an overall desirability function was used. The research deals with the optimization of multiple surface roughness parameters along with MRR in search of an optimal parametric combination (favorable process environment) capable of producing desired surface quality of the turned product in a relatively lesser time (enhancement in productivity). The multi-objective optimization resulted in a cutting speed of 210 m/min, a feed of 0.16 mm/rev, a depth of cut of 0.42 mm, and a nose radius of 0.40 mm. These machining conditions are expected to respond with the minimum tool wear and maximum the MRR, which correspond to a satisfactory overall desirability.


2014 ◽  
Vol 590 ◽  
pp. 294-298
Author(s):  
Pichai Janmanee ◽  
Somchai Wonthaisong ◽  
Dollathum Araganont

In this study, effect of machining parameters and wear mechanism in milling process of mold steel AISI-P20 and AISI-1050, using 10 mm twin flute type end mill diameter. The experimental results found that characteristics of milling surfaces and wear of the mill end were directly influenced by changes of parameters for all test conditions. As a result, the quality of milling surfaces also changed. However, mould steels which had the good quality surface is AISI-1050, with roughnesses of 2.120 μm. Quality milling surfaces were milled by using the most suitable parameter feed rate of 45 mm/min, a spindle speed of 637 rpm and a cut depth level of 3 mm, for both grades. Moreover, material removal rate and duration of the milling process, the milling end mills affect wear of the edge in every bite when the feed rate is low, high speed and level depth of cut at least. It was found that limited wear less will affect the surface roughness (Ra) represents the good quality surface.


1999 ◽  
Vol 122 (1) ◽  
pp. 59-69 ◽  
Author(s):  
William L. Cooper ◽  
Adrienne S. Lavine

The present work developed numerical codes that simulate steady-state grinding process kinematics. The three-dimensional modeling procedure entails the following: specifying the sizes, shapes, and positions of individual abrasive grains on the wheel surface; geometrically calculating the abrasive grains’ depth of cut distributions along the grinding zone as they pass through the grinding zone (neglecting wheel, abrasive grain, and workpiece deflections); using an empirical relationship to relate the abrasive grains’ geometric depths of cut to the grains’ actual depths of cut; and updating the workpiece surface to account for material removal. The resulting data include the abrasive grains’ average depth of cut distribution along the grinding zone, stock removal depth, stock removal rate, grinding zone shape, grinding zone length, percentage of grains impacting the workpiece, grain-workpiece impact frequency, etc. The calculated grinding zone lengths compare favorably with experimental data. This article examines a number of steady-state grinding processes. [S1087-1357(00)00101-5]


2011 ◽  
Vol 295-297 ◽  
pp. 1860-1865 ◽  
Author(s):  
Zhi Zhang ◽  
Chao Liu ◽  
Gong Duan Fan ◽  
Jing Luo ◽  
Yan Dong Wang

The control parameters of the removal of Chlorella pyrenoidosa, which was irradiated by low frequency ultrasonic, is optimized by using single factor experiments and response surface methodology (RSM). First of all, the approximate ranges of the ultrasonic frequency, the ultrasonic power and the irradiation time were estimated with single factor experiments for the further experiments. And then the optimized values of the three control parameters were determined, which were analyzed by using central composite design (CCD) and RSM. The results showed that the removal rate of chlorophyll-a could reach to 64.1% after the irradiation for 6.34min by using ultrasonic of 77.7 kHz and 250W. Ultrasonic technology can remove Chlorella pyrenoidosa cells in water quickly and effectively, so as to achieve the purpose of water purification.


2016 ◽  
Vol 24 (9) ◽  
pp. 1757-1773 ◽  
Author(s):  
Lorenzo Sallese ◽  
Niccolò Grossi ◽  
Antonio Scippa ◽  
Gianni Campatelli

Among the chatter suppression techniques in milling, active fixtures seem to be the most industrially oriented, mainly because these devices could be directly retrofittable to a variety of machine tools. The actual performances strongly depend on fixture design and the control logic employed. The usual approach in the literature, derived from general active vibration control applications, is based on the employment of adaptive closed-loop controls aimed at mitigating the amplitude of chatter frequencies with targeted counteracting vibrations. Whilst this approach has proven its effectiveness, a general application would demand a wide actuation bandwidth that is practically impeded by inertial forces and actuator-related issues. This paper presents the study of the performance of alternative open-loop actuation strategies in suppressing chatter phenomena, aiming at limiting the required actuation bandwidth. A dedicated time-domain simulation model, integrating fixture dynamics and the features of piezoelectric actuators, is developed and experimentally validated in order to be used as a testing environment to assess the effectiveness of the proposed actuation strategies. An extensive numerical investigation is then carried out to highlight the most influential factors in assessing the capability of suppressing chatter vibrations. The results clearly demonstrated that the regenerative effect could be effectively disrupted by actuation frequencies close to half the tooth-pass frequency, as long as adequate displacement is provided by the actuators. This could sensibly increase the critical axial depth of cut and hence improve the achievable material removal rate, as discussed in the paper.


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