scholarly journals Optimization of Surface Roughness in Micro-High Speed End Milling of Soda Lime Glass Using Uncoated Tungsten Carbide Tool with Compressed Air Blowing

2014 ◽  
Vol 607 ◽  
pp. 103-107 ◽  
Author(s):  
A.K.M. Nurul Amin ◽  
Mahmoud M.A. Nassar ◽  
Muammer Din Arif

Soda lime glass is a very important material in diverse manufacturing industries, including automotive, electronics, and aerospace. In these applications, the glass surface needs to be defect free and without impurities. However, the machining of glass is difficult due to its inherent brittleness which leads to brittle fracture and easy crack propagation. This research investigates the high speed micro-end milling of soda lime glass in order to attain ductile regime machining. It has been found by other researchers that ductile mode machining can avoid brittle fracture and sub-surface cracks. Also, in this study, a special air delivery nozzle is used to blow away the resultant chips and keep the machined surface clean. To accomplish this, Design Expert software and a commercial NC end mill were used to design and perform the machining runs, respectively. The surface roughness of the resultant surfaces was later analyzed with a surface profilometer. Microphotographs of the machined surfaces were also taken in order to see how effective the air blowing method is. The results of surface roughness measurements were then used to develop a quadratic empirical model for surface finish prediction. Finally, desirability function and genetic algorithms were used to predict the best combination of cutting parameters needed to obtain the lowest surface roughness. The predictions were later tested by experiments. The results demonstrate that this type of machining is viable and the roughness obtained is very low at 0.049 μm.

2015 ◽  
Vol 1115 ◽  
pp. 39-42
Author(s):  
A.K.M. Nurul Amin ◽  
A.A. Che Omar ◽  
M.A. Mohammed Kamal ◽  
Mahmoud M.A. Nassar ◽  
N.F. Mohd Zaib ◽  
...  

Soda lime glass is widely used in optics, chemical apparatus, camera lens, micro gas turbines, light bulbs etc. on account of its high hardness, corrosion resistance, and excellent optical properties. These require high dimensional accuracy and flawless surface finish. However, soda lime glass is inherently brittle leading to subsurface crack propagation and fracture which compromise its functionality. To avoid these defects, the machining needs to be performed under ductile mode conditions. Therefore, this research investigates the viability and requisite conditions for achieving ductile regime machining (DRM) in high speed micro-end milling of soda lime glass. Machining was performed at high cutting speeds (30,000 to 50,000 rpm), feed rate (5 to 15 mm/min), and depth of cut (3 to 7 μm). A surface profilometer was then used to measure the surface roughness and a scanning electron microscope (SEM) used to scrutinize the resultant machined surfaces. The results demonstrate that ductile streaks and rounded gummy chips (without sharp or jagged edges) are produced in all runs. In addition, there are no subsurface cracks and the minimum surface roughness attained is 0.08μm. These indicate that DRM of soda lime glass is obtainable using high-speed micro end milling in a conventional end mill with tungsten carbide inserts.


2015 ◽  
Vol 1115 ◽  
pp. 51-54 ◽  
Author(s):  
A.K.M. Nurul Amin ◽  
A.A. Che Omar ◽  
M.A.Mohammed Kamal ◽  
Mahmoud M.A. Nassar ◽  
N.F. Mohd Zaib ◽  
...  

Soda lime glass is used extensively in camera lens, micro gas turbines, light bulbs, tablewares, optics, and chemical apparatus owing to its high hardness, excellent optical properties, and good corrosion and chemical resistance. Such applications of soda lime glass demand high machining and finishing precision. On the other hand, machining of glass poses significant challenges due to its inherent brittleness. The process of removal of material from glass, if not done in ductile mode, can generate subsurface cracks and brittle fractures which have adverse effects on its functionality. This research investigates the high speed micro-end milling of soda lime glass in order to obtain ductile regime machining. It has been found by other researchers that ductile mode machining can avoid sub-surface cracks and brittle fractures. However, in ductile mode machining, the gummy chips settle permanently on the machined surface affecting adversely the surface finish. In order to avoid such chip settlement, compressed air was directed using a special air delivery nozzle to blow away the resultant gummy chips, thereby preventing them from settling on the machined surface. Response surface methodology (RSM) and a commercial NC end mill were used to design and perform the machining runs, respectively. Machining was done using: high spindle speeds from 30,000 to 50,000 rpm, feed rates from 5 to 15 mm/min, and depth of cuts from 3 to 7 μm. Three different diameter carbide tools were used: 0.5, 1, and 2 mm. A surface profilometer was used to analyze the surface roughness of the resultant machined surface. Subsequently, the data was used for finding the best combination of cutting parameters required to obtain the lowest surface roughness. The results demonstrate that high speed machining is a viable option for obtaining ductile regime machining and generating machined surfaces with very low surface roughness in the range of 0.08μm – 0.22 μm, using 0.5 mm carbide end mill cutter.


2012 ◽  
Vol 576 ◽  
pp. 111-114
Author(s):  
M.A. Mahmud ◽  
A.K.M. Nurul Amin ◽  
Muammer Din Arif

An experimental study of high speed machining of soda lime glass using directional compressed air blowing for removal of the ductile chips from the machined surface, is presented. High speed end milling of soda lime glass is performed on a vertical CNC milling machine to observe the effects of machining parameters i.e. spindle speed, depth of cut and feed rate on the resultant surface roughness. The design of the experiments was performed following the Central Composite Design (CCD) of the Response Surface methodology (RSM) using the Design Expert Software. Optimization of machining parameters was conducted using desirability function of the Design Expert software based on minimum surface roughness criterion. Finally, experimental verification tests were conducted to validate the predicted optimized value.


2012 ◽  
Vol 576 ◽  
pp. 107-110
Author(s):  
M.A. Mahmud ◽  
A.K.M. Nurul Amin ◽  
Muammer Din Arif

Glass materials play a vital role in advancement of science and technology. They have found wide spread application in the industry, in laboratory equipment and in micro-gas turbines. Due to their low fracture toughness they are very difficult to machine, moreover there are the chip depositions on the machined surface which affects surface finish under ductile mode cutting conditions. In this research, high speed end milling of soda lime glass is performed on CNC vertical milling machine to investigate the effects of machining parameters i.e. spindle speed, depth of cut, and feed rate on machined surface roughness. Design of experiments was performed following Central Composite Design (CCD) of Response Surface Methodology (RSM). Design Expert Software was used for generating the empirical mathematical model for average surface roughness. The model’s validity was tested to 95% confidence level by Analysis of Variance (ANOVA). Subsequent experimental results showed that the developed mathematical model could successfully describe the performance indicators, i.e. surface roughness, within the controlled limits of the factors that were considered.


2012 ◽  
Vol 576 ◽  
pp. 28-31 ◽  
Author(s):  
A.K.M. Nurul Amin ◽  
Noor Syairah Khalid ◽  
Siti Nurshahida Mohd Nasir ◽  
Muammer D. Arif

This research demonstrated the use of conventional milling machines with diamond coated tools, high speed attachments, and air blowing mechanisms for ductile mode machining of silicon and subsequently modeling and optimizing the resultant surface roughness. Spindle speed, depth of cut, and feed rate, ranges: 60,000 to 80,000 rpm, 10 to 20 µm, and 5 to 15 mm/min respectively, were considered as the independent machining parameters for the modeling process. Compressed air at 0.35 MPa was also provided to prevent chip deposition on the finished surfaces. The resultant surfaces were analysed using Optical and Scanning Electron (SEM) Microscopes as well as Wyko NT 1100 and SurfTest SV-500 profilometers. The response, surface roughness, was then modeled using a small Central Composite Design (CCD) in Response Surface Methodology (RSM). The quadratic relation was found to be most suitable following Fit and Summary and ANOVA analyses. The relation was then optimized using Desirability Function (DF) in Design of Expert (DOE) software. The optimum attainable surface roughness, which was validated using experimental runs, was found to be 0.11 µm which may be considered quite satisfactory.


Author(s):  
Mohamed Konneh ◽  
Mst. Nasima Bagum ◽  
Tasnim Firdaus Bt. Mohamed Arif ◽  
Mohammad Yeakub Ali

2010 ◽  
Vol 136 ◽  
pp. 86-90 ◽  
Author(s):  
Wei Zhang ◽  
Min Li Zheng ◽  
Ming Ming Cheng ◽  
Quan Wan

By using experiment cutter edge topography obtained by super depth three-dimension microscope, fits the cutter edge curve and calculate experiment cutter edge radius value; by high speed milling hardened steel experiment, individually researches cutter edge and cutting parameters influence on machined surface in high speed milling hardened steel with end-milling cutter and ball-end milling cutter. The experiment analysis results show that under the same cutting parameters condition, machined surface roughness in high speed end-milling cutter milling is better than in high speed ball-end milling; within experiment selected cutting parameter range, cutter edge radius is the main influence factor on machined surface roughness in high speed end- milling hardened steel, while the influence on machined surface roughness in high speed ball-end milling hardened steel is not obvious. In end-milling, when edge radius and milling depth are in the same order magnitude or the difference is not obvious, milling depth should be a little bigger than selected cutter edge radius value.


2013 ◽  
Vol 670 ◽  
pp. 70-75 ◽  
Author(s):  
Wei Zhang ◽  
M.L. Zheng ◽  
M.M. Cheng ◽  
W.T. Wang

By using experiment cutter edge topography obtained by super depth three-dimension microscope, fits the cutter edge curve and calculate experiment cutter edge radius value; by high speed milling hardened steel experiment, individually researches cutter edge and cutting parameters influence on machined surface in high speed milling hardened steel with end-milling cutter and ball-end milling cutter. The experiment analysis results show that under the same cutting parameters condition, machined surface roughness in high speed end-milling cutter milling is better than in high speed ball-end milling; within experiment selected cutting parameter range, cutter edge radius is the main influence factor on machined surface roughness in high speed end- milling hardened steel, while the influence on machined surface roughness in high speed ball-end milling hardened steel is not obvious. In end-milling, when edge radius and milling depth are in the same order magnitude or the difference is not obvious, milling depth should be a little bigger than selected cutter edge radius value.


2014 ◽  
Vol 493 ◽  
pp. 546-551 ◽  
Author(s):  
Safian Sharif ◽  
Habib Safari ◽  
Sudin Izman ◽  
Denni Kurniawan

The surface quality generated when high speed dry end milling (HSDEM) Ti-6Al-4V-ELI titanium alloy with coated and uncoated carbide tools were investigated. Evaluation was conducted using TiAlN+TiN coated and uncoated cemented carbide tools under different high cutting speeds and feed rates conditions. Surface roughness and cutting forces were measured when using new tools. The milled surface quality and corresponding alteration were characterized through electron microscopy. Within the investigated conditions high quality surface finish was obtained on the machined surface. Increasing cutting speed from 200 to 300 m/min during the process improved the surface finished particularly under lower feed rates. In term of generated surface quality, uncoated H25 grade carbide tools out performed coated F40M grade specifically at the higher cutting conditions. The main damages observed after HSDEM on the surface for all machining conditions contain redeposited materials, feed marks, and tool edge marks. Under both tested feed rates the resultant cutting force decreased by increasing the cutting speeds and uncoated carbide tools provide the lower cutting forces compared to coated types.


2017 ◽  
Vol 740 ◽  
pp. 145-151
Author(s):  
Mohamed Konneh ◽  
Mst. Nasima Bagum ◽  
A.K.M. Nurul Amin ◽  
Amira Fatin Asyah

Brittle materials like soda lime glass can be machined in ductile mode under controlled machining conditions (feed rate, depth of cut, small tool edge radius) using high speed to generate a desired surface finish. The heat generated in high speed machining tends to promote ductile machining. In this paper, heat assisted high speed end milling is investigated to explore machinability of the soda lime glass. The heat assisted machining thus generates low surface finish on the machined workpiece. The heat assisted high speed end milling of soda lime was carried out using uncoated 2 flute carbide end mill at a constant depth of cut 25 μm, while the spindle speed and feed rate were varied from 30,000 to 50,000 rpm and 45 to 75 mm/min, respectively. The applied temperature was varied from 200 °C to 300 °C. The observations of machined surface were done on Surf-test (SV-514) and Scanning Electron microscope (SEM). A quadratic model for roughness (Ra) was developed using Central Composite Design of experiment. The optimum Ra, 0.10 μm was achieved at 49,570 rpm, 58 mm/min feed rate and heating temperature at 238°C. It is found that cutting speed has the greatest influence on the surface roughness value, followed by feed rate and heating temperature.


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