Raja Izamshah - Academia.edu (original) (raw)
Papers by Raja Izamshah
Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, 2022
In the aerospace field, titanium alloys are extensively used for the airframe and engine parts to... more In the aerospace field, titanium alloys are extensively used for the airframe and engine parts to improve aircraft fuel consumption. Drilling through these parts in a single-shot process to produce high quality holes is challenging. During drilling, high temperatures are generated owing to the friction between the cutting tool and workpiece, causing the process becomes inefficient in terms of tool life and surface quality. To reduce the temperature produced in the cutting zone, different types of cooling techniques during drilling have been used by researchers. In this study, the feasibility of quarry dust suspension as coolant in drilling of titanium alloy was performed. The effects of different concentrations of quarry dust on surface roughness, thrust force, and burr formation were evaluated, and their machining performances were compared with those obtained using aluminium oxide suspension. Before the experiments, both suspensions were prepared by dispersing quarry dust and alum...
Key Engineering Materials, 2010
In an attempt to decrease weight, new commercial and military aircraft are designs with unitised ... more In an attempt to decrease weight, new commercial and military aircraft are designs with unitised monolithic metal structural components which contains of thinner ribs (i.e., walls) and webs (i.e., floors). Most of the unitised monolithic metal structural components are machined from solid plate or forgings with the start-to-finish weight ratio of 20:1. The resulting thin-walled structure often suffers a deformation which causes a dimensional surface error due to the action of the cutting force generated during the machining process. To alleviate the resulting surface errors, current practices rely on machining through repetitive feeding several times and manual calibration which resulting in long cycle times, low productivity and high operating cost. A finite element analysis (FEA) machining model is developed in this project to specifically predict the distortion or deflection of the part during end milling process. The model aims to provide an input for downstream decision making ...
This paper presents some research into the wear and damage of the flat end-mill cutting tools und... more This paper presents some research into the wear and damage of the flat end-mill cutting tools under machining with copper based metal. A series of cutting tests have been carried at cutting time 35, 70, 105, and 140 minutes. The cutting speed, depth of cut and feed rate were kept constant at 2750 rpm, 0.05 mm and 280 mm/min, respectively.
Manufacturing Technology
Nowadays, Carbon Fibre Reinforced Polymer (CFRP) materials are extensively used as substitutes fo... more Nowadays, Carbon Fibre Reinforced Polymer (CFRP) materials are extensively used as substitutes for metal parts in aircraft and automotive components since they are lighter in weight. However, micro drilling CFRP materials during the assembly process poses various challenges such as low hole accuracy and delamination. Hence, an experiment has been executed to investigate the influence of micro drilling parameters towards hole accuracy. The spindle speed and feed rate are the machining parameters that have been considered in this experiment. Three different optimum parameters have been obtained from previous experiments, involving the spindle speed combinations of 8,000, 10,762 and 11,017 min-1 with a feed rate of 0.01 mm/rev. A drill bit with a diameter of 0.9 mm is used to drill approximately 300 holes. It has been revealed that the combination of the spindle speed of 11,017 min-1 and feed rate of 0.01 mm/rev produce high hole accuracy at the 2 nd hole compared to the 300 th hole due to the presence of uncut fibres at the 300 th hole which have reduced the hole area. Hence, outcome of this research could provide the benefit to the industries in term of manufacturing time and materials expenditure.
Faculty of Mechanical Engineering Universiti Teknologi MARA (UiTM), 2017
Lecture Notes in Mechanical Engineering, 2019
Flow analysis of three plate family injection mould using pin point gate that consist of four cav... more Flow analysis of three plate family injection mould using pin point gate that consist of four cavities was studied. The responses investigated were volumetric shrinkage, in-cavity residual stress and deflection. The experiment was conducted using Taguchi method with L9 orthogonal array. The parameters involved in this study were mould temperature, melt temperature, injection time and cooling time. The plastic specimens were designed using CATIA V5 and the drawing was imported to Autodesk Moldflow Insight (AMI) simulation software environment. The feed system such as sprue, runner, pin-point gate and cooling system of three plate mould were designed inside the simulation software. Flow analysis was conducted under cool + fill + pack + warp analysis. From the flow analysis using Taguchi method, the lowest volumetric shrinkage obtained is 7.907%. For other responses, the lowest in-cavity residual stress and deflection found are 27.69 MPa and 0.9203 mm respectively. After optimization using optimized parameters, the value of volumetric shrinkage is reduced about 2.88% to 7.678%. In-cavity residual stress is reduced about 0.14% to 27.41 MPa, while deflection of plastic parts is reduced about 0.30% to 0.9176 mm. From ANOVA results, it is found that melt temperature is the most important factors affecting volumetric shrinkage, in-cavity residual stress and deflection of plastic parts.
Lecture Notes in Mechanical Engineering, 2019
As for the diesel engine, it is well known as one of the largest contributors to environmental po... more As for the diesel engine, it is well known as one of the largest contributors to environmental pollution, which cause by exhaust emission. Therefore, due to the energy constraint, the rising cost of raw petroleum and environmental change with the expanding request for vitality preservation and environmental protection further enhancement in fuel adaptability and emission reduction in a diesel engine are direly required. The outflows framed are indigent upon the engine configuration, power yield and working burden. The complete ignition of fuel prompts real diminishments in the development of fumes discharges. Complete on combustion will leads a significant mechanical power for the vehicle, which is perfect on the air-fuel mixture. With a specific end goal to diminish NOx and PM arrangement it is important to comprehend the components of its development.
World Review of Science, Technology and Sustainable Development, 2018
Recycling and reuse of waste carbon fibre for making value-added products is a wise disposal mana... more Recycling and reuse of waste carbon fibre for making value-added products is a wise disposal management. This research is focusing on the tribological potential of nitric acid treated recycled carbon fibres (rCFs) as reinforcement in polypropylene (PP). The coefficients of friction and wear rate of this composite at different fibre loadings of 0.5, 1, 3, 5 and 7 wt% were determined for the effect of acid treatment. Composites with acid treated rCF showed smaller COF (0.30-0.33) than those with untreated rCF (0.51-0.55). In contrast, wear rate was higher for the composites filled with treated rCF than those with untreated rCF. The increment of fibre loading from 5 wt% to 7 wt% decreased the wear rate for both untreated and acid treated composites owing the formation of stable patch film and transfer film. The films effectively prevented direct contact of the composites with the counterface; hence, wear was greatly inhibited.
International Journal of Precision Engineering and Manufacturing, 2018
This research aims to identify a high-quality, efficient, and low-cost micro-hole drilling proces... more This research aims to identify a high-quality, efficient, and low-cost micro-hole drilling process through glass plates that employs an electroplated diamond tool with different drill bits. Three different drill bits were tested to determine how varying the chip discharge volume influences chip discharge performance, which is an important factor that affects the effectiveness of the drilling process. The chip discharge performance of each electroplated diamond tool was experimentally investigated by observing the drilling quality and the number of the drilled holes. From the experimental results, it was found that the drilled chips could not discharge smoothly when the drill bit possesses a small chip discharge volume, leading to the drill bit breaking, which thus limits the number of drilled holes. Furthermore, the changes in thrust force and the crack size were high, and there were also cracks on the drilled glass plate. However, drilling with a drill bit that possesses a larger chip discharge volume resulted in excellent chip discharge performance and increased the number of drilled holes. This type of drill bit is effective in drilling holes through glass plates, with minimum hole defects and no issues associated with chips clogging the hole during drilling.
The International Journal of Advanced Manufacturing Technology, 2019
This present paper deals with the chip segmentation in ball nose end milling process of Inconel 7... more This present paper deals with the chip segmentation in ball nose end milling process of Inconel 718 for turbine blades. It deals with characterizing the chip morphologies and microstructure investigations under minimum quantity lubrication (MQL) condition. In this study, the effects of cutting speed (Vc), radial depth of cut (WoC), and axial depth of cut (DoC) on chip segmentation are presented. The study proved that chip dimensional values were dominantly affected by the Vc, WoC, and DoC, while the frequency of dislodged chips was affected by notch wear. It was observed that the star anise-like chips formed are associated with the tool failure.
The Proceedings of Design & Systems Conference, 2015
Procedia Engineering, 2017
Drilling of bone is the most important part of the internal and external fixation processes in or... more Drilling of bone is the most important part of the internal and external fixation processes in orthopaedic surgery. This surgical procedure usually is performed manually with a hand-held tool and is greatly dependent on the surgeon skill. Imprecise manipulation of the hand-held tool can cause the drill skidding across the bone surface and leads to a localized increase in temperature resulting a thermal necrosis on the soft tissue surrounding the hole surface. The magnitudes of the friction energy are greatly dependent with the drill geometry design and the penetration angle. For the sake of importance on studying this phenomenon, this paper aim to investigate the effects of drill geometry on temperatures rise and hole surface in bone drilling procedure. Totals of 17 drills were designed and tested with different geometry namely point angle, helix angle and web thickness on different penetration angle (0 0 , 15 0 , and 30 0) to mimic the manually control penetration by the surgeon. From the conducted investigation, the most significant parameter that affects the temperature rise and holes surface quality was the penetration angle followed by the point angle. In addition, the interaction between helix angle and web thickness also controlled the drilling temperature and the performance of the hole surface.
The optimization of processing parameters on warpage of polypropylene (PP) in the application of ... more The optimization of processing parameters on warpage of polypropylene (PP) in the application of injection moulding machine was studied. The appropriate parameters were adjusted to reduce the warpage defect on the tensile test specimen of dog bone. The type of injection moulding machine used in this research is Arburg 420C 800-250C. Four parameters that have been investigated; injection pressure, clamping pressure, back pressure and holding pressure. A concept of design of experiment (DOE) has been applied using Taguchi method to determine the suitable parameters. To measure the warpage of the dog bone, digital height gauge was used to measure the flatness of the part surface. According the analysis of variance (ANOVA), the most significant factor that effect the warpage was holding pressure by 57.82%, followed with back pressure by 25.75%, clamping pressure by 16.27% and injection pressure by 0.16%. It is found that the optimum parameters setting that have been obtained were injection pressure at 950 bar, clamping pressure at 600 kN, holding pressure at 700 bar and back pressure at 75 bar. The depreciation value of warpage minimum index in this experiment was decreased by 4.6% after confirmation run.
A friction stir welding (FSW) is normally used to join two similar or dissimilar laps or butt joi... more A friction stir welding (FSW) is normally used to join two similar or dissimilar laps or butt joints for alloys and/or materials. FSW produces good joint efficiency, especially for dissimilar ones as compared to other welding methods. In the present study, a single-pass FSW is used for butt joining of the 5083 and 6061 aluminum alloy plates lap to steel (electro-galvanized steel) by employing the plunging and diffusion assisted bonding techniques. The backscattered electron detector image obtained from a scanning electron microscope showed the existence of an intermetallic reaction layer at the welded interface zone. The compositions of the intermetallic layers were investigated by utilizing energy-dispersive X-ray spectroscopy. The tensile tests were used to examine the joint efficiency of specimens welded by using different welding parameters. It was found that at 900 rpm rotational speed and 20 mm/min welding speed, the maximum joint efficiency was 73%.
International Journal of Mechanical and Materials Engineering, 2015
Background: Laser micromachining is currently used in the MEMS production to replace the traditio... more Background: Laser micromachining is currently used in the MEMS production to replace the traditional etching process which consumes longer time to complete. The objective of this study is to investigate the drilling capability of industrial CO 2 laser in processing of silicon wafer. Methods: In this work, the holes were drilled on P-type silicon wafer with thickness of 525 μm. Geometrical characteristic of holes produce, which is diameter entrance that depends on laser parameter were investigated and analyzed. Analysis of Variance (ANOVA) was used to analyze the result and generated an appropriate model for the laser drilling processing. Results: The laser parameters involved were laser power, pulse frequency and duty cycle. The experimental results showed the entrance diameter of drilling holes was increase when the laser power and duty cycle increased. Conclusion: The entrance diameter of drilling hole decreases when the pulse frequency increases.
The High Pressure Waterjet Assisted Machining (HPWAM) is a machining process that involves high p... more The High Pressure Waterjet Assisted Machining (HPWAM) is a machining process that involves high pressure coolant being delivered at the cutting zone. This paper investigates the performance of conventional and HPWAM when machining Ti-6Al-4V titanium alloy. The evaluations were based on the tool life, wear mechanisms, surface profile and chip formation. The coolant pressures, cutting speed, feed rate and depth of cut were set at 11-20.3 MPa, 110m/min, 0.15 mm/rev and 0.5 mm respectively. The results showed that improved tool life as much as 195% can be achieved when machining Ti-6Al-4V with HPWAM due to better coolant access at the cutting zone. Surfaces generated when machining with HPWAM were generally acceptable with negligible physical damage. Long and continuous chip formations were observed when machining in conventional coolant supply corresponded to the low coolant pressure. Increasing coolant pressure significantly reduces the chip size, resulting in a reduction in the tool-chip contact and improvement in lubrication at the contact interfaces. This paper provides the understanding and correct use of HPWAM especially when machining Ti-6Al-4V alloy.
Applied Mechanics and Materials, 2013
Metal matrix composite is composite material that combines the metallic properties of matrix allo... more Metal matrix composite is composite material that combines the metallic properties of matrix alloys and additional element to reinforce the product. This paper evaluates the machining performance of uncoated carbide and coated carbide in terms of surface integrity during end milling of LM6 aluminium MMC. The parameter of cutting speed, feed rate and axial depth of cut were kept constant at 3000 rpm spindle speed, 60 mm/min feed rate and 0.5 axial dept of cut. The radial depth of cut were varied from 0.01mm to 0.1 mm. The results indicated that uncoated carbide show the better performance in terms of surface roughness and surface profile, as compared to coated carbide. On the other hand, coated carbide cutting tools suffered with built-up-edge formation at the tool edge, hence caused shearing effect and deterioration at the tool-chip interface. This study is expected to provide understanding of machining metal matrix composites based materials.
Applied Mechanics and Materials, 2014
This paper details the application of Taguchi method to determine the effect of cutter geometrica... more This paper details the application of Taguchi method to determine the effect of cutter geometrical features for machining Polyetheretherketones (PEEK) thermoplastic. The planned experiment was conducted by using Taguchi’s orthogonal array taking into account the ball nose geometrical parameters such as helix angle, rake angle, clearance angle and number of flute. The measured response is the machined surface roughness, which is important for the component functionality. In addition, ANOVA was used to validate the percentage contribution of each factor. The obtained results reveals that, less number of flutes is the main factor contributed towards fine surface roughness for this thermoplastic. Fewer flutes provide a smooth flow of chip ejection and minimize the friction on the cutting zone which is vital for polymeric material such as PEEK. High helix and rake angles also influence the machined surface roughness as both angles provide optimum shearing force to produced better surface...
Abstract: The High Pressure Waterjet Assisted Machining (HPWAM) is a machining process that invol... more Abstract: The High Pressure Waterjet Assisted Machining (HPWAM) is a machining process that involves high pressure coolant being delivered at the cutting zone. This paper investigates the performance of conventional and HPWAM when machining Ti-6Al-4V titanium alloy. The evaluations were based on the tool life, wear mechanisms, surface profile and chip formation. The coolant pressures, cutting speed, feed rate and depth of cut were set at 11-20.3 MPa, 110m/min, 0.15 mm/rev and 0.5 mm respectively. The results showed that improved tool life as much as 195 % can be achieved when machining Ti-6Al-4V with HPWAM due to better coolant access at the cutting zone. Surfaces generated when machining with HPWAM were generally acceptable with negligible physical damage. Long and continuous chip formations were observed when machining in conventional coolant supply corresponded to the low coolant pressure. Increasing coolant pressure significantly reduces the chip size, resulting in a reduction i...
Journal of Advanced Research in Fluid Mechanics and Thermal Sciences, 2022
In the aerospace field, titanium alloys are extensively used for the airframe and engine parts to... more In the aerospace field, titanium alloys are extensively used for the airframe and engine parts to improve aircraft fuel consumption. Drilling through these parts in a single-shot process to produce high quality holes is challenging. During drilling, high temperatures are generated owing to the friction between the cutting tool and workpiece, causing the process becomes inefficient in terms of tool life and surface quality. To reduce the temperature produced in the cutting zone, different types of cooling techniques during drilling have been used by researchers. In this study, the feasibility of quarry dust suspension as coolant in drilling of titanium alloy was performed. The effects of different concentrations of quarry dust on surface roughness, thrust force, and burr formation were evaluated, and their machining performances were compared with those obtained using aluminium oxide suspension. Before the experiments, both suspensions were prepared by dispersing quarry dust and alum...
Key Engineering Materials, 2010
In an attempt to decrease weight, new commercial and military aircraft are designs with unitised ... more In an attempt to decrease weight, new commercial and military aircraft are designs with unitised monolithic metal structural components which contains of thinner ribs (i.e., walls) and webs (i.e., floors). Most of the unitised monolithic metal structural components are machined from solid plate or forgings with the start-to-finish weight ratio of 20:1. The resulting thin-walled structure often suffers a deformation which causes a dimensional surface error due to the action of the cutting force generated during the machining process. To alleviate the resulting surface errors, current practices rely on machining through repetitive feeding several times and manual calibration which resulting in long cycle times, low productivity and high operating cost. A finite element analysis (FEA) machining model is developed in this project to specifically predict the distortion or deflection of the part during end milling process. The model aims to provide an input for downstream decision making ...
This paper presents some research into the wear and damage of the flat end-mill cutting tools und... more This paper presents some research into the wear and damage of the flat end-mill cutting tools under machining with copper based metal. A series of cutting tests have been carried at cutting time 35, 70, 105, and 140 minutes. The cutting speed, depth of cut and feed rate were kept constant at 2750 rpm, 0.05 mm and 280 mm/min, respectively.
Manufacturing Technology
Nowadays, Carbon Fibre Reinforced Polymer (CFRP) materials are extensively used as substitutes fo... more Nowadays, Carbon Fibre Reinforced Polymer (CFRP) materials are extensively used as substitutes for metal parts in aircraft and automotive components since they are lighter in weight. However, micro drilling CFRP materials during the assembly process poses various challenges such as low hole accuracy and delamination. Hence, an experiment has been executed to investigate the influence of micro drilling parameters towards hole accuracy. The spindle speed and feed rate are the machining parameters that have been considered in this experiment. Three different optimum parameters have been obtained from previous experiments, involving the spindle speed combinations of 8,000, 10,762 and 11,017 min-1 with a feed rate of 0.01 mm/rev. A drill bit with a diameter of 0.9 mm is used to drill approximately 300 holes. It has been revealed that the combination of the spindle speed of 11,017 min-1 and feed rate of 0.01 mm/rev produce high hole accuracy at the 2 nd hole compared to the 300 th hole due to the presence of uncut fibres at the 300 th hole which have reduced the hole area. Hence, outcome of this research could provide the benefit to the industries in term of manufacturing time and materials expenditure.
Faculty of Mechanical Engineering Universiti Teknologi MARA (UiTM), 2017
Lecture Notes in Mechanical Engineering, 2019
Flow analysis of three plate family injection mould using pin point gate that consist of four cav... more Flow analysis of three plate family injection mould using pin point gate that consist of four cavities was studied. The responses investigated were volumetric shrinkage, in-cavity residual stress and deflection. The experiment was conducted using Taguchi method with L9 orthogonal array. The parameters involved in this study were mould temperature, melt temperature, injection time and cooling time. The plastic specimens were designed using CATIA V5 and the drawing was imported to Autodesk Moldflow Insight (AMI) simulation software environment. The feed system such as sprue, runner, pin-point gate and cooling system of three plate mould were designed inside the simulation software. Flow analysis was conducted under cool + fill + pack + warp analysis. From the flow analysis using Taguchi method, the lowest volumetric shrinkage obtained is 7.907%. For other responses, the lowest in-cavity residual stress and deflection found are 27.69 MPa and 0.9203 mm respectively. After optimization using optimized parameters, the value of volumetric shrinkage is reduced about 2.88% to 7.678%. In-cavity residual stress is reduced about 0.14% to 27.41 MPa, while deflection of plastic parts is reduced about 0.30% to 0.9176 mm. From ANOVA results, it is found that melt temperature is the most important factors affecting volumetric shrinkage, in-cavity residual stress and deflection of plastic parts.
Lecture Notes in Mechanical Engineering, 2019
As for the diesel engine, it is well known as one of the largest contributors to environmental po... more As for the diesel engine, it is well known as one of the largest contributors to environmental pollution, which cause by exhaust emission. Therefore, due to the energy constraint, the rising cost of raw petroleum and environmental change with the expanding request for vitality preservation and environmental protection further enhancement in fuel adaptability and emission reduction in a diesel engine are direly required. The outflows framed are indigent upon the engine configuration, power yield and working burden. The complete ignition of fuel prompts real diminishments in the development of fumes discharges. Complete on combustion will leads a significant mechanical power for the vehicle, which is perfect on the air-fuel mixture. With a specific end goal to diminish NOx and PM arrangement it is important to comprehend the components of its development.
World Review of Science, Technology and Sustainable Development, 2018
Recycling and reuse of waste carbon fibre for making value-added products is a wise disposal mana... more Recycling and reuse of waste carbon fibre for making value-added products is a wise disposal management. This research is focusing on the tribological potential of nitric acid treated recycled carbon fibres (rCFs) as reinforcement in polypropylene (PP). The coefficients of friction and wear rate of this composite at different fibre loadings of 0.5, 1, 3, 5 and 7 wt% were determined for the effect of acid treatment. Composites with acid treated rCF showed smaller COF (0.30-0.33) than those with untreated rCF (0.51-0.55). In contrast, wear rate was higher for the composites filled with treated rCF than those with untreated rCF. The increment of fibre loading from 5 wt% to 7 wt% decreased the wear rate for both untreated and acid treated composites owing the formation of stable patch film and transfer film. The films effectively prevented direct contact of the composites with the counterface; hence, wear was greatly inhibited.
International Journal of Precision Engineering and Manufacturing, 2018
This research aims to identify a high-quality, efficient, and low-cost micro-hole drilling proces... more This research aims to identify a high-quality, efficient, and low-cost micro-hole drilling process through glass plates that employs an electroplated diamond tool with different drill bits. Three different drill bits were tested to determine how varying the chip discharge volume influences chip discharge performance, which is an important factor that affects the effectiveness of the drilling process. The chip discharge performance of each electroplated diamond tool was experimentally investigated by observing the drilling quality and the number of the drilled holes. From the experimental results, it was found that the drilled chips could not discharge smoothly when the drill bit possesses a small chip discharge volume, leading to the drill bit breaking, which thus limits the number of drilled holes. Furthermore, the changes in thrust force and the crack size were high, and there were also cracks on the drilled glass plate. However, drilling with a drill bit that possesses a larger chip discharge volume resulted in excellent chip discharge performance and increased the number of drilled holes. This type of drill bit is effective in drilling holes through glass plates, with minimum hole defects and no issues associated with chips clogging the hole during drilling.
The International Journal of Advanced Manufacturing Technology, 2019
This present paper deals with the chip segmentation in ball nose end milling process of Inconel 7... more This present paper deals with the chip segmentation in ball nose end milling process of Inconel 718 for turbine blades. It deals with characterizing the chip morphologies and microstructure investigations under minimum quantity lubrication (MQL) condition. In this study, the effects of cutting speed (Vc), radial depth of cut (WoC), and axial depth of cut (DoC) on chip segmentation are presented. The study proved that chip dimensional values were dominantly affected by the Vc, WoC, and DoC, while the frequency of dislodged chips was affected by notch wear. It was observed that the star anise-like chips formed are associated with the tool failure.
The Proceedings of Design & Systems Conference, 2015
Procedia Engineering, 2017
Drilling of bone is the most important part of the internal and external fixation processes in or... more Drilling of bone is the most important part of the internal and external fixation processes in orthopaedic surgery. This surgical procedure usually is performed manually with a hand-held tool and is greatly dependent on the surgeon skill. Imprecise manipulation of the hand-held tool can cause the drill skidding across the bone surface and leads to a localized increase in temperature resulting a thermal necrosis on the soft tissue surrounding the hole surface. The magnitudes of the friction energy are greatly dependent with the drill geometry design and the penetration angle. For the sake of importance on studying this phenomenon, this paper aim to investigate the effects of drill geometry on temperatures rise and hole surface in bone drilling procedure. Totals of 17 drills were designed and tested with different geometry namely point angle, helix angle and web thickness on different penetration angle (0 0 , 15 0 , and 30 0) to mimic the manually control penetration by the surgeon. From the conducted investigation, the most significant parameter that affects the temperature rise and holes surface quality was the penetration angle followed by the point angle. In addition, the interaction between helix angle and web thickness also controlled the drilling temperature and the performance of the hole surface.
The optimization of processing parameters on warpage of polypropylene (PP) in the application of ... more The optimization of processing parameters on warpage of polypropylene (PP) in the application of injection moulding machine was studied. The appropriate parameters were adjusted to reduce the warpage defect on the tensile test specimen of dog bone. The type of injection moulding machine used in this research is Arburg 420C 800-250C. Four parameters that have been investigated; injection pressure, clamping pressure, back pressure and holding pressure. A concept of design of experiment (DOE) has been applied using Taguchi method to determine the suitable parameters. To measure the warpage of the dog bone, digital height gauge was used to measure the flatness of the part surface. According the analysis of variance (ANOVA), the most significant factor that effect the warpage was holding pressure by 57.82%, followed with back pressure by 25.75%, clamping pressure by 16.27% and injection pressure by 0.16%. It is found that the optimum parameters setting that have been obtained were injection pressure at 950 bar, clamping pressure at 600 kN, holding pressure at 700 bar and back pressure at 75 bar. The depreciation value of warpage minimum index in this experiment was decreased by 4.6% after confirmation run.
A friction stir welding (FSW) is normally used to join two similar or dissimilar laps or butt joi... more A friction stir welding (FSW) is normally used to join two similar or dissimilar laps or butt joints for alloys and/or materials. FSW produces good joint efficiency, especially for dissimilar ones as compared to other welding methods. In the present study, a single-pass FSW is used for butt joining of the 5083 and 6061 aluminum alloy plates lap to steel (electro-galvanized steel) by employing the plunging and diffusion assisted bonding techniques. The backscattered electron detector image obtained from a scanning electron microscope showed the existence of an intermetallic reaction layer at the welded interface zone. The compositions of the intermetallic layers were investigated by utilizing energy-dispersive X-ray spectroscopy. The tensile tests were used to examine the joint efficiency of specimens welded by using different welding parameters. It was found that at 900 rpm rotational speed and 20 mm/min welding speed, the maximum joint efficiency was 73%.
International Journal of Mechanical and Materials Engineering, 2015
Background: Laser micromachining is currently used in the MEMS production to replace the traditio... more Background: Laser micromachining is currently used in the MEMS production to replace the traditional etching process which consumes longer time to complete. The objective of this study is to investigate the drilling capability of industrial CO 2 laser in processing of silicon wafer. Methods: In this work, the holes were drilled on P-type silicon wafer with thickness of 525 μm. Geometrical characteristic of holes produce, which is diameter entrance that depends on laser parameter were investigated and analyzed. Analysis of Variance (ANOVA) was used to analyze the result and generated an appropriate model for the laser drilling processing. Results: The laser parameters involved were laser power, pulse frequency and duty cycle. The experimental results showed the entrance diameter of drilling holes was increase when the laser power and duty cycle increased. Conclusion: The entrance diameter of drilling hole decreases when the pulse frequency increases.
The High Pressure Waterjet Assisted Machining (HPWAM) is a machining process that involves high p... more The High Pressure Waterjet Assisted Machining (HPWAM) is a machining process that involves high pressure coolant being delivered at the cutting zone. This paper investigates the performance of conventional and HPWAM when machining Ti-6Al-4V titanium alloy. The evaluations were based on the tool life, wear mechanisms, surface profile and chip formation. The coolant pressures, cutting speed, feed rate and depth of cut were set at 11-20.3 MPa, 110m/min, 0.15 mm/rev and 0.5 mm respectively. The results showed that improved tool life as much as 195% can be achieved when machining Ti-6Al-4V with HPWAM due to better coolant access at the cutting zone. Surfaces generated when machining with HPWAM were generally acceptable with negligible physical damage. Long and continuous chip formations were observed when machining in conventional coolant supply corresponded to the low coolant pressure. Increasing coolant pressure significantly reduces the chip size, resulting in a reduction in the tool-chip contact and improvement in lubrication at the contact interfaces. This paper provides the understanding and correct use of HPWAM especially when machining Ti-6Al-4V alloy.
Applied Mechanics and Materials, 2013
Metal matrix composite is composite material that combines the metallic properties of matrix allo... more Metal matrix composite is composite material that combines the metallic properties of matrix alloys and additional element to reinforce the product. This paper evaluates the machining performance of uncoated carbide and coated carbide in terms of surface integrity during end milling of LM6 aluminium MMC. The parameter of cutting speed, feed rate and axial depth of cut were kept constant at 3000 rpm spindle speed, 60 mm/min feed rate and 0.5 axial dept of cut. The radial depth of cut were varied from 0.01mm to 0.1 mm. The results indicated that uncoated carbide show the better performance in terms of surface roughness and surface profile, as compared to coated carbide. On the other hand, coated carbide cutting tools suffered with built-up-edge formation at the tool edge, hence caused shearing effect and deterioration at the tool-chip interface. This study is expected to provide understanding of machining metal matrix composites based materials.
Applied Mechanics and Materials, 2014
This paper details the application of Taguchi method to determine the effect of cutter geometrica... more This paper details the application of Taguchi method to determine the effect of cutter geometrical features for machining Polyetheretherketones (PEEK) thermoplastic. The planned experiment was conducted by using Taguchi’s orthogonal array taking into account the ball nose geometrical parameters such as helix angle, rake angle, clearance angle and number of flute. The measured response is the machined surface roughness, which is important for the component functionality. In addition, ANOVA was used to validate the percentage contribution of each factor. The obtained results reveals that, less number of flutes is the main factor contributed towards fine surface roughness for this thermoplastic. Fewer flutes provide a smooth flow of chip ejection and minimize the friction on the cutting zone which is vital for polymeric material such as PEEK. High helix and rake angles also influence the machined surface roughness as both angles provide optimum shearing force to produced better surface...
Abstract: The High Pressure Waterjet Assisted Machining (HPWAM) is a machining process that invol... more Abstract: The High Pressure Waterjet Assisted Machining (HPWAM) is a machining process that involves high pressure coolant being delivered at the cutting zone. This paper investigates the performance of conventional and HPWAM when machining Ti-6Al-4V titanium alloy. The evaluations were based on the tool life, wear mechanisms, surface profile and chip formation. The coolant pressures, cutting speed, feed rate and depth of cut were set at 11-20.3 MPa, 110m/min, 0.15 mm/rev and 0.5 mm respectively. The results showed that improved tool life as much as 195 % can be achieved when machining Ti-6Al-4V with HPWAM due to better coolant access at the cutting zone. Surfaces generated when machining with HPWAM were generally acceptable with negligible physical damage. Long and continuous chip formations were observed when machining in conventional coolant supply corresponded to the low coolant pressure. Increasing coolant pressure significantly reduces the chip size, resulting in a reduction i...