Design and Investigate of Flushing System for Electrical Discharge Machining (EDM) Application

Electrical Discharge Machining (EDM) is high precision machining process in which no actual contact between the workpiece and electrode during sparking. Dielectric fluid play a role as flushing medium and semiconductor between workpiece and electrode to stabilization and controlled spark gap ionization condition. In real condition, nozzle flushing system in EDM machine not able to complete remove debris formed during machining and affect the machining performance. Improper flushing due to lack of guideline at setup position of nozzle and inlet pressure caused low material removal rate, irregular tool and higher cost on raw material. To overcome this problem, the design and investigate of flushing system in EDM application is required. The design and investigation undergo by simulation of ANSYS Computational Fluid Dynamics (CFD) with a virtual experiment to accurate prediction of flushing performance. The influence of nozzle size and inlet pressure supplied on flushing efficiency were analyzed to avoid improper flushing on die-sinking EDM process. The simulation and experiments clarified that the higher inlet pressure, P=0.20 bar and larger nozzle diameter, D=6mm resulting in higher total pressure which is 2647.16 Pa. Furthermore, the streamline of velocity and eddy viscosity contour in the work tank using to analyze the turbulence zone by nozzle flushing obtained by the CFD analysis. The condition in case 5 (D=5mm, P=0.15 bar) is more efficiency on debris removal rate based on the result of high total pressure on machining zone and eddy viscosity contour showed the turbulence zone only formed area near to outlet of system. The model results have been shown good agreement with experiment and co-relation data

Design and Develop of Open Architecture CNC Movement Control System for Analysing Precision Motion of EDM Machine

Since the third Industry Revolution (IR3.0), automation become a key technology in industry especially CNC machine. An EDM machine is CNC based that able to reduce the process time, increase the productivity of manufacturing process, and duel with complex task. Therefore, it was one of the best choice to become the education element in manufacturing field. However, high in cost and complexity in structure were the weaknesses and limitations of EDM machine. An open architecture CNC movement control system was studied in order to create a high flexibility, affordable, and simple movement control system for EDM machine. LabVIEW was chosen as the main controller software and NI MyRIO as the main processor in this movement control system. The hardware was built by using open architecture components which reusable and low in cost. This system was able to control the movement of X, Y, and Z axis of the EDM machine in term of distance travel. The time counter in LabVIEW program was used as the feedback system due to absent of encoder as the position feedback element. The relationship between traveled time and distance traveled was determined for the adjustment and programs for single direction, dual direction, specific distance movement, multi axis movement and stop when sensor triggered were developed. The desired value was compared with the actual distance travel in order to calculate the percentage of error of the control system. The percentage of error for X, Y, Z and the gap created was 0.37%, 0.38%, 0.49% and 2.9% respectively. This experimental study will fulfill three objectives. First is to design an open architecture CNC movement control system in X, Y, and Z axis for EDM application. Second is to integrate and analyze the CNC movement control system with the machine hardware. Lastly is to analyze the performance of the developed movement control system with respect to the CNC movement system

A study on cryogenic supercritical carbon dioxide coolant delivery technique when machining of AISI 1045 steel

The machining operation involves a material removal process and develop high temperature due to the friction force. The heat generated at the region of cutting edge has critical influences on machining process. It can increase cutting tool wear, reduce tool life, get rise to thermal deformation and might consequence to microcracks. The application of cutting fluid at the cutting zone by conventional process could overcomes the aforementioned problems to some extent via cooling and lubrication process. However, the waste of cutting fluid might be profuse and its impact on the environment. A new efficient process, cryogenic cooling using carbon dioxide gas (CO2) has been introduced on improving the cooling process. This technique is more economical in coolant usage while maintaining significant performance including cutting temperature, cutting force and surface roughness. The pulse mode of CO2 cooling spray under supercritical state has been used to corroborate the machining process by reducing the cutting zone temperature as to reducing coolant usage

Analysis of worker performances using statistical process control in fish paste otak-otak food industries

This research focuses on the improvement of Small and Medium Enterprises through the used of Process Statistical Control (SPC). An industry that focuses on the fish paste (known as “otak-otak”) production was taken as the case study in this research and the problems analysed are based on the real industrial experiences. The data collection for control charts were recorded for two weeks consisting of working time for each operator. The data were collected in subgroup of 16 with sample size of 5. The collection of data for weight of product was recorded randomly for the whole production line, while data collection of working time of operation was taken randomly from each operator every 30 minutes of the working hour. From this study, there are several problems had been detected in the process that been categories in six element that is people, method, measurement, machine, environment and materials. There were lack of motivation, lack of skill, lack of supervision, manual operation, lack of standard of procedure, waiting time in process, weight-based operator, lack of quality check, not using weight scale, conveyer that sometimes got stuck, spoon for tools, no automation, poor layout arrangement, talking while working, small working space, lack of hygiene, waiting time for material and easily spoiled. The findings can be used as the guideline to the industries for future production improvement. The industries would focus on elimination or reduction of the problems through their innovative solution

Powder Mixed Dielectric in Electrical Discharge Machining of Inconel 718 / Said Ahmad...[et al.]

Inconel 718 is one of the most difficult to cut material due to its, high hardness, high toughness, and poor thermal conductivity results in heat concentrated in the cutting zone, making it ineffective to be processed through conventional machining. So usually, an electrical discharge machining (EDM) is chosen in order to overcome such limitations. However, EDM is known as a slow machining process. Thus, by employing powder mixed in the dielectric fluid it is believe to enhance the machining efficiency. To achieve high performance in EDM for this research, higher peak current, Ip up to 40A, pulse duration, ton up to 400μs and powder concentration, Cp up to 4g/l were selected as the main parameters. Copper tungsten (CuW) was used as an electrode. The circulating dielectric system called High Performance EDM (HPEDM) was applied to conduct the experiment involving powder mixed dielectric. Their influence on the machinabilities of the material removal rate (MRR), and electrode wear rate (EWR), were experimentally investigated. The surface topography of the machined work piece and surface morphology of the electrode also have been observed. The results have shown that, at a highest Ip=40A and the lowest ton=200μs with Cp=4g/l yields the highest MRR. The improvement is almost 50% when comparing without powder concentration at the same parameter settings. In the case of EWR, lowest value of EWR was obtained at Ip=20A, ton=400μs and Cp=0g/l

Determination of heat flux intensity distribution and laser absorption rate of AISI D2 tool steel

The prediction of fluctuated temperature distribution generated by pulsed wave laser in laser assisted micro milling (LAMM) is crucial. The selection of processing parameter by minimize the effect on the processing characteristic is decisive to ensure the machining quality is high. Determining the effect of heat generated in underneath surface is important to make sure that the cutting tools are able to cut the material with maximum depth of cut and minimum defects in term of tool wear and tool life. In this study the simulation was carried by using Ansys APDL. In order to confirm the actual and distribution irradiation of temperature from simulation, an experimental was done to validate the results. The experiment was conducted by using Nd:YAG laser with wavelength 1064 nm

Numerical analysis of laser heating for laser assisted micro milling application

The promising processing techniques of micro scale parts are very important in products miniaturization and functions enhancement. Combination of two or more processing techniques gives better processing performance especially when dealing with difficult-to-cut materials. For that reason, the combination of laser beam and micro milling process has been widely studied and proven efficient in reducing cutting force and tool life extension. However, this process needs a precise temperature control in order to eliminate heat effect generated by laser beam irradiation. In this study, temperature distributions are determined numerically to characterize the melted zone and heat affected zone geometry. From the results, the estimation of tool and micro milling cutter distance together with the allowable depth of cut are determined

Mechanical Performances of Twill Kenaf Woven Fiber Reinforced Polyester Composites

Natural fibres have been explored by many researchers. Natural fibres have the potential aspect to replace glass fibre in fibre-reinforced composites application. Kenaf is also one of the selected natural fibres that have bio resource profit regarding on their capability to absorb energy absorption especially. This study focused on the twill yarn kenaf woven composite structure. Composites were prepared using the hand lay-up method with different type of orientation each layered arrangement by Taguchi. The hardened composites were cured for 24 hours before it was shaped according to ASTM D3039. Taguchi method is used in this study for optimization which can reduce the time consumed rather than using experimental approach. The result shows orientations were significant on tensile and modulus strength performances. After optimizations, the values of tensile and modulus strength was 55.738 MPa and 5761.704 Joule, which is increasing 3.77% for tensile strength and 4.23% for Young modulus. By comparing fracture mechanism before and after optimizations, there was clear decreasing fracture surface. It indicated that, the mechanical behavior performances of the twill woven kenaf reinforced composites can be effectively improved by this method

Electrical discharge machining of polycrystalline diamond using copper electrode – finishing condition

Research on machining process of Polycrystalline Diamond (PCD) is becoming important as the material was believed suitable to be used for cutting tools of advanced aeronautical structure. Electrical Discharge Machining (EDM) was regarded as the suitable method to machine PCD due its noncontact process nature. The objective of this research is to determine the influence of several EDM parameter such as sparking current, pulse duration, and pulse interval to the material removal rate and surface roughness of the machined PCD. Instead of significantly influenced the material removal rate, the sparking current was also highly influenced tha surface roughness. Highest material removal rate of approximately 0.005mm3/s was recorded by the EDM process with the highest current used of 5A, and lowest pulse interval of 1µs. The influence of pulse duration is not clearly seen at the lowest pulse interval used. On the other hand, 0.4µm was the lowest surface roughness value obtained in this research indicated by the highest sparking current, highest sparking duration and lowest sparking interval of 5A, 1µs and 1µs respectively

Numerical analysis of laser preheating for laser assisted micro milling of Inconel 718

Micro milling of super alloy materials such as nickel based alloys such as Inconel 718 is challenging due to the excellent of its mechanical properties. Therefore, new techniques have been suggested to enhance the machinability of nickel based alloys by pre-heating the workpiece’s surface to reduce its strength and ductility. The prediction of fluctuated temperature distribution generated by pulsed wave laser in laser assisted micro milling (LAMM) is crucial. The selection of processing parameter by minimize the effect on the processing characteristic is decisive to ensure the machining quality is high. Determining the effect of heat generated in underneath surface is important to make sure that the cutting tools are able to cut the material with maximum depth of cut and minimum defects in terms of tool wear and tool life. In this study the simulation was carried by using Ansys APDL. In order to confirm the actual and distribution irradiation of temperature from simulation, an experimental was done to validate the results. The experiment was conducted by using Nd:YAG laser with wavelength 1064 nm