In-Situ Measurement of Electrode Wear During EDM Drilling using Vision System

Machine vision system is an image-based technology used to perform automatic inspection and analysis such as process control and robot guidance. The aim for this project is to develop a fully automated electrode wear detection system in EDM by using machine vision system and apply this system in detecting electrode wear in EDM. This project was conducted using DSLR camera as monitoring device. The electrode undergo hole making process with a depth of 10 mm, 20 mm, 30 mm, 40 mm, and 50 mm to observe the electrode condition. The image of the electrode will be remotely captured from the laptop and then will undergo image processing process using Matlab software to calculate and determine the electrode wear. The output of this project will show the images of the electrode wear and its wear value. Findings from the project showed that this system is suitable and applicable in EDM super drill machine to monitor the tool condition

Surface Erosion of Carbon Steel 1045 During Waterjet Peening

The present study investigates the effect of waterjet treatment on the surface characteristics of the carbon steel 1045. The effect of waterjet treatment parameters namely number of jet passes and pressure was investigated. An increase in the number of jet passes as well as pressure leads to a higher roughness and more erosion of the surface. The damage features consist of various fracture mechanism modes occurred at the initial and evolved damage stage. The ferrite phase experienced more damage than the pearlite phase. However, the damage was more concentrated along the grain boundaries. The shearing force from the jet lateral flow raised the circumferential rim and created lateral cracks and sub-tunnels which might eventually be removed in the subsequent jet passes. The hardness of the treated specimens increased with an increase in the number of jet passes and pressure

Performance analysis of abrasive waterjet machining process at low pressure

Normally, a commercial waterjet cutting machine can generate water pressure up to 600 MPa. This range of pressure is used to machine a wide variety of materials. Hence, the price of waterjet cutting machine is expensive. Therefore, there is a need to develop a low cost waterjet machine in order to make the technology more accessible for the masses. Due to its low cost, such machines may only be able to generate water pressure at a much reduced rate. The present study attempts to investigate the performance of abrasive water jet machining process at low cutting pressure using self developed low cost waterjet machine. It aims to study the feasibility of machining various materials at low pressure which later can aid in further development of an effective low cost water jet machine. A total of three different materials were machined at a low pressure of 34 MPa. The materials are mild steel, aluminium alloy 6061 and plastics Delrin®. Furthermore, a traverse rate was varied between 1 to 3 mm/min. The study on cutting performance at low pressure for different materials was conducted in terms of depth penetration, kerf taper ratio and surface roughness. It was found that all samples were able to be machined at low cutting pressure with varied qualities. Also, the depth of penetration decreases with an increase in the traverse rate. Meanwhile, the surface roughness and kerf taper ratio increase with an increase in the traverse rate. It can be concluded that a low cost waterjet machine with a much reduced rate of water pressure can be successfully used for machining certain materials with acceptable qualities

Investigation of indentation size effect and R-curve behaviour of Li2O–SiO2 and Li2O–2SiO2 glass ceramics

Indentation size effect (ISE) and R-curve behaviour of Li2O–SiO2 and Li2O–2SiO2 glass ceramics are investigated using micro-indentation and indentation-strength (IS) techniques, respectively. Vickers micro-indentations were applied on both materials at the load of 0.10–19.6 N to determine the load influence on the measured hardness. For the IS-measured fracture toughness, the load ranged from 1.96 to 19.6 N. The hardness decreased with increasing load by 20% and 18% on Li2O–SiO2 and Li2O–2SiO2 glass ceramics, respectively, indicating the ISE behaviour on both materials. The fracture toughness increased with the load by 27% and 59% on Li2O–SiO2 and Li2O–2SiO2 glass ceramics, respectively, signifying the R-curve behaviour. The ISE behaviour of both materials was analysed using the Meyer's, Hays–Kendall (HK), proportional specimen resistance (PSR), Nix–Gao (NG), modified PSR (MPSR) and elastic plastic deformation (EPD) models while the R-curve behaviour was analysed by the fractional power law. The Meyer's index of both materials was less than 2, strongly confirming the ISE existence. The HK, PSR and NG models were only suitable to determine intrinsic Vickers hardness for Li2O–2SiO2 glass ceramic while the MPSR and EPD models were successful for both materials. The fractional power law gave higher R-curve steepness for Li2O–2SiO2 than Li2O–SiO2 glass ceramics. Also, material and brittleness indices predicted, respectively, higher quasi-plasticity and better machinability for Li2O–2SiO2 than Li2O–SiO2 glass ceramics indicating superior performance in the former to the latter. Finally, this study presents a new significant insight into the micro-mechanisms of fracture tolerance behaviour of these glass ceramics which is critical to their functional performance as structural ceramics

Optimization of EDM Injection Flushing Type Control Parameters Using Grey Relational Analysis on AISI 304 Stainless Steel Workpiece

This paper deals with optimization of Electrical Discharge Machining (EDM) Injection flushing type control parameters on multi-performance optimization characteristics instead of single performance optimization using Grey Relational Analysis (GRA) Method. The experimental control parameters were being optimized according to their various machining characteristics namely material removal rate (MRR), electrode wear ratio (EWR) and surface roughness (SR) using copper as the tool and AISI 304 stainless steel as the workpiece. This parameters optimization was based on Taguchi’s orthogonal array (OA) combined with GRA. A grey relational grade (GRG) calculated based on GRA was used to optimize the EDM process with multiple performance characteristics and Taguchi’s L18 OA was used to plan the experiments. The machining parameters selected are polarity, pulse on duration, discharge current, discharge voltage, machining depth, machining diameter and dielectric liquid pressure. Results shown that machining performance was improved effectively using this approach. The predicted responses at optimum parameter levels are in good agreement with the results of confirmation experiments conducted for verification tests

Investigation on the multiple plies structure of aluminum-lithium alloy and glass fiber composite with respect to deformation failure

The deformation behavior and mechanical properties based on the aluminum-lithium alloys (FMLs) was investigated to optimize the manufacturing process and further interface interaction. The primary structures of the FML composites were made with two sets of plies. From there, six secondary composites with different fibre sheet orientations were made. Then, interlaminar tensile, flexural, and peeling properties of FMLs were tested. The fiber orientation role in the case of failure behaviors of FMLs under different conditions was also revealed. The results have indicated that the plies design significantly enhanced the interlaminar properties of the FMLs and orientation of fiber laying has significantly affected the flexural strength. The peeling test has shown higher fiber-to-metal interfacial bonding with the value of ≥80 N m−2 over metal-to-metal adhesion. The plies increase the mechanical properties of composite based at fiber orientation and thickness, but too much impairs performance. The 3/2 plies showed a value of ≤385 MPa, which has better results in axial structure analysis than over 4/2 composite layers. The peak values appeared under different parameters like adhesive bonding and parallel fiber orientation, represented in the qualitative analysis section. The surface microscopy of aluminum-lithium alloy sheet and cross-section failure morphology of composite has been done at a different sighting. Surface characterization, fiber orientation breakdown, and deformation morphology have been studied concerning alloys' elongated grains and micro pits

Effect Of Surface Topography Of 8090 Al-Li Alloy During Abrasive Waterjet Peening Process

Abrasive water jet (AWJ) peening strengthening test of aluminum-lithium alloy (8090Al–Li) was carried out with a variety of pressure process parameters. The research was done on the roughness as well as the morphology of the treated samples. A high dislocation density formed in the area of the workpiece that was subjected to the peening process. The result was a surface that was both rough and hardened. The abrasive effect took place in the area where the collapse took place. The fact that this method was the most effective option for treating the surface of the metal was very beneficial. According to the findings, the surface roughness, grain size, micro-strain, erosive effect, and micro-hardness of the alloy were all considerably affected by various peening settings. In this instance, the rise in pressure caused the surface roughness to increase as well. In addition, the microcrystalline structure was shown to have diminished in the treated area by the abrasive peening. The research demonstrated how the effect of varying the peening pressure can reduce the amount of surface roughness on materials. In comparison to the initial sample, the roughness reached its highest values of 62 μm to 92 μm and rose by 7.87 to 27.56 %. These results indicate a significant increase. In comparison, the average surface roughness of the equivalent area increased to 30.04 μm. According to the experimental observation, the AWJ peening collapse limits that were acquired by the proposed sample surface and metallographic images were extremely complete and accurate

Talent screening identification instrument: prospective art & design students / Syahrini Shawalludin...[et al.]

The Faculty of Art & Design, Universiti Teknologi MARA (UiTM) offers programs for Diploma, Undergraduate and Post Graduate wishing to pursue art and design studies. A total of nine programs are offered; Fine Arts, Graphic & Digital Media, Fashion, Industrial Design, Textile Design, Fine Metal, Ceramics, Fine Art and Printing Technology. To date, the student selection process will be selected through a screening process inclusive of an interview session, drawing test, and colour-blind test that is compulsory for entry into the following Diploma programs. The study argues how the current and past practice on screening traces and identifies the talent in art and design since the candidates have limited knowledge and exposure in the ten areas offered. Consequently, this also affects the interest, learning process, potential skills, and limits the career development if the wrong programs are offered to them. This study identifies a solution in identifying the relevant talent and aptitude in art and design. A total of 148 candidates were involved in this study. An instrument in a form of questionnaire were given to the candidates which provides a systematic criterion in determining if the candidate has interest and talent in the nine areas provided. This study focuses on the importance of the talent identification screening instrument to assess talent for potential students who plans to embark their studies under the Faculty of Art & Design in Universiti Teknologi MARA (UiTM). The study suggests and define the talent screening instrument is an added value to the talent identification process which has been justified relevant and beneficial to be implemented to the student selection process

Surface Roughness Analysis on Sheet Metals During AWJ Machining Using Low Pressure

The present study discusses the effect of abrasive waterjet machining (AWJ) parameters on surface roughness during cutting of sheets metals of stainless steel 304 and pure copper. A relatively low hydraulic pressure below 150 MPa was used. Several machining parameters were chosen namely pressure, traverse rate, stand-off distance and abrasive mass flowrate. It was found that increasing the pressure leads to an increase in the surface roughness. Varying other parameters did not clearly show any trends on the surface roughness. A higher surface roughness happened during AWJ machining of stainless steel 304 compared to pure copper due to its former higher hardness. The surface roughness at the upper region closer to the top surface is higher than the bottom section regardless of machining parameters. Furthermore, embedded particles are more dominant in pure copper than stainless steels 304. It can be concluded that a low water pressure in AWJ machining process can be used to cut sheet metals successfully with acceptable cutting quality

Investigation on welding distortion in stainless steel sheet using gas tungsten arc welding process

TIG welding has found wide applications in various industries for sheet metal joining process due to its simple process with high quality welds. However, it still experiences various form of defects to the weld components such as incomplete fusion, undercut, cracks and distortion which might affect production accuracy, appearance and strength of weld components. It is obvious that various welding parameters can affect the welding distortion. The present study attempts to investigate the effect of welding parameters namely welding current and diameter of filler rod on the distortion angle, tensile strength and change in microstructures. The experiment was performed on a closed butt joint type of welding using a commercial TIG welding machine. A full factorial experiment was utilized in the present study. A higher welding current produced more heat input into the weld zone thus resulting in a higher angular distortion. Similarly, a bigger diameter of filler rod produced more angular distortion attributed to the bigger size of weld bead. While, the tensile strength increased with an increase of welding current whereas, the filler rod diameters showed no clear and direct effect. Based on the microstructures of weld area, there were full penetration joints with no obvious defects such as hot cracking and porosities