Prediction of Surface Roughness in Compressed Air Jet Assisted High Speed End Milling of Silicon Using Diamond Coated Tools

2012 ◽  
Vol 576 ◽  
pp. 41-45
Author(s):  
A.K.M. Nurul Amin ◽  
M.A. Mahmud ◽  
M.D. Arif
Keyword(s):  
Mathematical Model ◽  
Surface Roughness ◽  
Surface Finish ◽  
High Speed ◽  
End Milling ◽  
Silicon Wafers ◽  
Compressed Air ◽  
Machining Parameters ◽  
High Quality ◽  
Ductile Mode

The majority of semiconductor devices are made up of silicon wafers. Manufacturing of high-quality silicon wafers includes numerous machining processes, including end milling. In order to end mill silicon to a nano-meteric surface finish, it is crucial to determine the effect of machining parameters, which influence the machining transition from brittle to ductile mode. Thus, this paper presents a novel experimental technique to study the effects of machining parameters in high speed end milling of silicon. The application of compressed air, in order to blow away the chips formed, is also investigated. The machining parameters’ ranges which facilitate the transition from brittle to ductile mode cutting as well as enable the attainment of high quality surface finish and integrity are identified. Mathematical model of the response parameter, the average surface roughness (Ra) is subsequently developed using RSM in terms of the machining parameters. The model was determined, by Analysis of Variance (ANOVA), to have a confidence level of 95%. The experimental results show that the developed mathematical model can effectively describe the performance indicators within the controlled limits of the factors that are being considered.

Comparison of Surface Roughness Attainable in High Speed End Milling of Silicon with Air Blowing on Conventional and CNC Milling Machines

2012 ◽  
Vol 576 ◽  
pp. 19-22
Author(s):  
A.K.M. Nurul Amin ◽  
Siti Nurshahida Mohd Nasir ◽  
Noor Syairah Khalid ◽  
Muammer Din Arif
Keyword(s):  
Surface Roughness ◽  
High Speed ◽  
End Milling ◽  
Compressed Air ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Ductile Mode ◽  
Milling Machines ◽  
Air Blowing ◽  
Machined Surfaces

Review of past research indicated that ductile mode machining of silicon can produce surface roughness values as low as 0.22 µm, which is about half of 0.40 µm, the usual standard roughness value to avoid fine grinding and rough polishing operations. The current research investigated and compared the surface roughness and integrity attained in high speed end milling of silicon (using diamond coated tools) under ductile mode machining conditions. Two different types of end milling machines were utilized, CNC and conventional milling machines. Additionally, the effect of compressed air on the resultant surface roughness was investigated. The air blowing fixture, designed for mounting the compressed air hose, consisted of fixed and movable jaws, air blower clamp, fasteners, and the air gun. Air blowing was used to prevent silicon chips from settling on the machined surface, since it was observed to be an acute problem in high speed ductile mode machining of silicon. The three machining parameters: spindle speed, depth of cut, and feed rate were varied within the ranges 60,000 to 80,000 rpm, 10 to 20 µm, and 5 to 15 mm/min respectively. The resultant machined surfaces were analysed using Wyko NT 1100 and SurfTest SV-500 profilometers in order to measure the attaine surface roughnesses and surface profile. The machined surfaces had almost no deposition and was of excellent finish.

Optimization of Cutting Parameters in High Speed End Milling of Soda Lime Glass with Coated Carbide Tools Using Directional Compressed Air Blowing

2012 ◽  
Vol 576 ◽  
pp. 111-114
Author(s):  
M.A. Mahmud ◽  
A.K.M. Nurul Amin ◽  
Muammer Din Arif
Keyword(s):  
Surface Roughness ◽  
High Speed ◽  
End Milling ◽  
Soda Lime ◽  
Compressed Air ◽  
Soda Lime Glass ◽  
Machining Parameters ◽  
Design Expert ◽  
Air Blowing ◽  
Optimization Of Cutting Parameters

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.

Surface Roughness Model for High Speed End Milling of Soda Lime Glass Using Carbide Coated Tools with Compressed Air Blowing

2012 ◽  
Vol 576 ◽  
pp. 107-110
Author(s):  
M.A. Mahmud ◽  
A.K.M. Nurul Amin ◽  
Muammer Din Arif
Keyword(s):  
Mathematical Model ◽  
Surface Roughness ◽  
Gas Turbines ◽  
High Speed ◽  
End Milling ◽  
Soda Lime ◽  
Depth Of Cut ◽  
Soda Lime Glass ◽  
Machining Parameters ◽  
Machined Surface

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.

Prediction of Surface Roughness in High Speed Machining of Inconel 718

2011 ◽  
Vol 264-265 ◽  
pp. 1193-1198
Author(s):  
Mokhtar Suhaily ◽  
A.K.M. Nurul Amin ◽  
Anayet Ullah Patwari
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Inconel 718 ◽  
High Speed ◽  
End Milling ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Machining Process ◽  
Depth Of Cut ◽  
High Speed Machining

Surface finish and dimensional accuracy is one of the most important requirements in machining process. Inconel 718 has been widely used in the aerospace industries. High speed machining (HSM) is capable of producing parts that require little or no grinding/lapping operations within the required machining tolerances. In this study small diameter tools are used to achieve high rpm to facilitate the application of low values of feed and depths of cut to investigate better surface finish in high speed machining of Inconel 718. This paper describes mathematically the effect of cutting parameters on Surface roughness in high speed end milling of Inconel 718. The mathematical model for the surface roughness has been developed in terms of cutting speed, feed rate, and axial depth of cut using design of experiments and the response surface methodology (RSM). Central composite design was employed in developing the surface roughness models in relation to primary cutting parameters. Machining were performed using CNC Vertical Machining Center (VMC) with a HES510 high speed machining attachment in which using a 4mm solid carbide fluted flat end mill tool. Wyko NT1100 optical profiler was used to measure the definite machined surface for obtaining the surface roughness data. The predicted results are in good agreement with the experimental one and hence the model can be efficiently used to predict the surface roughness value with in the specified cutting conditions limit.

Micro-Ball Endmilling of Tungsten Carbide for Micro-Molding and Prototyping Applications

2012 ◽  
Vol 516 ◽  
pp. 591-594 ◽  
Author(s):  
Muhammad Arif ◽  
Mustafizur Rahman ◽  
Yoke San Wong ◽  
Kui Liu
Keyword(s):  
Tungsten Carbide ◽  
Inclination Angle ◽  
Surface Finish ◽  
End Milling ◽  
Depth Of Cut ◽  
Work Piece ◽  
Machining Parameters ◽  
Cutting Mechanism ◽  
High Quality ◽  
Ball End Milling

This paper presents micro-ball end milling of tungsten carbide using a CBN cutter to investigate its capability for machining slots for micro-moulds. Crack-free slots were machined at different axial depths of cut by inclining the work piece surface at different angles to the spindle axes to study the influence of these machining parameters on the cutting mechanism and surface finish. The experimental results show that up to 150 µm deep slots can be finished efficiently on tungsten carbide work pieces without leaving any fracture marks. It was identified that the chip disposal ability of micro-ball end milling reduced with increase in axial depth of cut. The cutting action was more efficient in up milling cuts compared to that in down milling when machining a slot. The inclination of the work piece proved propitious for machining slots with high-quality finish on tungsten carbide work pieces and a larger inclination angle also facilitated chip disposal.

Effect of Cutter Diameters on Surface Roughness Attained in High Speed End Milling of Soda Lime Glass

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 ◽  
...  
Keyword(s):  
Surface Roughness ◽  
High Speed ◽  
End Milling ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
End Mill ◽  
Machined Surface ◽  
Ductile Mode ◽  
Ductile Regime Machining ◽  
Brittle Fractures

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.

Statistical Approach to Modeling & Optimization of Surface Roughness in High Speed End Milling of Silicon with Diamond Coated Tools

2012 ◽  
Vol 576 ◽  
pp. 28-31 ◽  
Author(s):  
A.K.M. Nurul Amin ◽  
Noor Syairah Khalid ◽  
Siti Nurshahida Mohd Nasir ◽  
Muammer D. Arif
Keyword(s):  
Surface Roughness ◽  
Response Surface ◽  
High Speed ◽  
End Milling ◽  
Desirability Function ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Coated Tools ◽  
Milling Machines ◽  
Air Blowing

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.

Machinability Improvement by Workpiece Preheating during End Milling AISI H13 Hardened Steel

2011 ◽  
Vol 264-265 ◽  
pp. 888-893
Author(s):  
Mokhtar Suhaily ◽  
A.K.M. Nurul Amin ◽  
Anayet Ullah Patwari
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Inconel 718 ◽  
High Speed ◽  
End Milling ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Machining Process ◽  
Depth Of Cut ◽  
High Speed Machining

Surface finish and dimensional accuracy is one of the most important requirements in machining process. Inconel 718 has been widely used in the aerospace industries. High speed machining (HSM) is capable of producing parts that require little or no grinding/lapping operations within the required machining tolerances. In this study small diameter tools are used to achieve high rpm to facilitate the application of low values of feed and depths of cut to investigate better surface finish in high speed machining of Inconel 718. This paper describes mathematically the effect of cutting parameters on Surface roughness in high speed end milling of Inconel 718. The mathematical model for the surface roughness has been developed in terms of cutting speed, feed rate, and axial depth of cut using design of experiments and the response surface methodology (RSM). Central composite design was employed in developing the surface roughness models in relation to primary cutting parameters. Machining were performed using CNC Vertical Machining Center (VMC) with a HES510 high speed machining attachment in which using a 4mm solid carbide fluted flat end mill tool. Wyko NT1100 optical profiler was used to measure the definite machined surface for obtaining the surface roughness data. The predicted results are in good agreement with the experimental one and hence the model can be efficiently used to predict the surface roughness value with in the specified cutting conditions limit.

Modeling and Optimization of Critical Depth in High Speed End Milling of Soda Lime Glass

2012 ◽  
Vol 576 ◽  
pp. 36-40
Author(s):  
M.A. Mahmud ◽  
A.K.M. Nurul Amin ◽  
M.D. Arif
Keyword(s):  
Mathematical Model ◽  
High Speed ◽  
End Milling ◽  
Plastic State ◽  
Soda Lime Glass ◽  
Machining Parameters ◽  
Critical Depth ◽  
Display Time ◽  
Machined Surface ◽  
Good Surface

One of the most hard and brittle material is glass. Due to the properties of low fracture toughness it is very difficult to being machined having good surface quality. Hence it is required to be machined in such a way that brittle fracture does not appear in the new machined surface, which is only possible in ductile mode machining or the removal of material in the plastic state. Above all machining of glass is the most challenging in current state of mechanical machining. The experimental results show that the developed mathematical model can effectively describe the performance indicators within the controlled limits of the factors that are being considered. This paper presents the mathematical model and optimization results of an experimental study of high speed end milling by the consideration of amplitude time display (Time Domain), FFT Diagram (Frequency Domain) and surface characteristics to find out the maximum critical depth for higher material removal which is crack free surface having good surface finishes. Mathematical model of the response parameter, the critical depth is subsequently developed using RSM in terms of the machining parameters. The model was determined, by Analysis of Variance (ANOVA), to have a confidence level of 95%. The optimization was carried out by the optimization features of Design Expert software.

Prediction and Investigation of Surface Quality in High Speed End-Milling of Silicon to Eliminate Conventional Finishing Operations

2011 ◽  
Vol 418-420 ◽  
pp. 1237-1241
Author(s):  
A.K.M. Nurul Amin ◽  
Mohd Dali M Ismail ◽  
Muhammad Iqbal Musa ◽  
Anayet Ullah Patwari
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
High Speed ◽  
End Milling ◽  
High Surface ◽  
Small Diameter ◽  
Dimensional Accuracy ◽  
Cutting Parameters ◽  
Machining Process ◽  
Dry Cutting

Surface finish and dimensional accuracy are two of the most important requirements in machining process. High speed machining (HSM) is capable of producing parts that require little or no grinding/lapping operations within the required machining tolerances. In HSM determination of the optimum combination of cutting parameters for achieving the required level of quality, such as, minimum possible surface roughness and maximum tool life is a very important task. Silicon is conventionally finished using grinding followed by polishing and lapping to achieve required surface finish and surface integrity. In this study small diameter tools are used to achieve high rpm to facilitate the application of low values of feed and depths of cut to ensure high surface roughness values through achievement of ductile mode machining of silicon. Investigations on the effect cutting parameters of high speed end milling on surface finish and integrity of silicon has been conducted to minimizing the amount of finishing requirement in machining of silicon, with the objective of reducing cost and increasing effectiveness of silicon manufacturing process. In this work statistical models were developed using the capabilities of Response Surface Methodology (RSM) to predict the surface roughness in high speed flat end milling of silicon under dry cutting conditions.

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