Effendi Mohamad

Microstructural evolution and mechanical properties of thixoformed A319 alloys containing variable amounts of magnesium

The effects of Mg content on the microstructure and tensile properties of thixoformed A319 alloys were studied. The samples were thixoformed at 50% liquid content and some of the thixoformed samples were subjected to the T6 heat treatment. The samples were then examined by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy and X-ray diffraction (XRD) analysis as well as tensile tests. The results showed that magnesium was able to refine the eutectic silicon in the samples. It was also observed that a compact Al9FeMg3Si5 phase was formed when the magnesium content was 1.0% and 1.5%. The results also revealed that as the magnesium content in the alloy increases, the tensile strengths of the thixoformed alloys also increase. The ultimate tensile strength, yield strength and elongation to fracture of the thixoformed A319 heat treated alloy were 298 MPa, 201 MPa and 4.5%, respectively, whereas the values of the thixoformed heat treated alloy with 1.5% Mg content were 325 MPa, 251 MPa and 1.4%, respectively. Thixoformed A319 alloy showed a dimple fracture behaviour, while thixoformed A319 alloys with 1.5% Mg showed a mixed mode fracture behaviour, where dimple and cleavage ruptures were seen on the fracture surface of the samples.

Integration of e-learning and simulation to user training programme of SMED

Simulation has become popular since the last few years as an effective training method for lean manufacturing tools such as Single Minute Exchange of Die (SMED), Kanban, and preventive maintenance. As training is crucial to achieve successful implementation of lean manufacturing tools, this paper introduces a simulation-based training system for lean manufacturing tools focusing on SMED called lean manufacturing tools training system (LMTTS-SMED). LMTTS-SMED consists of e-learning module and S-module. E-learning module provides users with theory of SMED, success stories of SMED implementation, and quizzes. S-module guides users to implement SMED on a simulated production line. This paper also proposes a framework that integrates LMTTS with the current user training programmes for SMED, i.e., classroom training, workshops, simulation games, on-job training, and factory visits. LMTTS-SMED will be utilised by users after attending the training programme. This way, execution of pilot studies of SMED in real life production floor will be supported. Finally, the design of LMTTS-SMED and its training scenario based on the proposed framework are also described in this paper.

Configuring robot work cell in manufacturing industry

In this study, we have focused on the configuration of robot work cells since their ever-increasing adoption and the current manufacturing trends towards the automation along with a continuous improvement of the innovative technology. Also, we have highlighted and reviewed the different emerging strategies which focus on the configuration work and we have discussed and proposed a configuration strategy with its methodology. The earlier studies were reviewed to present an overview regarding any future work in this field. Additionally, a configuration strategy along with all the details regarding its phases and frameworks had been proposed which may assist in the development of flexible configuration system in the future. The primary purpose of this work is to propose a strategy with a methodology of robot work cell configuration for addressing few sustainability issues such as to improve configuration time, to optimise human and expert involvement and to capitalise available resource for investment.

Automated platform for designing multiple robot work cells

Designing the multiple robot work cells is very knowledge-intensive, intricate, and time-consuming process. This paper elaborates the development process of a computer-aided design program for generating the multiple robot work cells which offer a user-friendly interface. The primary purpose of this work is to provide a fast and easy platform for less cost and human involvement with minimum trial and errors adjustments. The automated platform is constructed based on the variant-shaped configuration concept with its mathematical model. A robot work cell layout, system components, and construction procedure of the automated platform are discussed in this paper where integration of these items will be able to automatically provide the optimum robot work cell design according to the information set by the user. This system is implemented on top of CATIA V5 software and utilises its Part Design, Assembly Design, and Macro tool. The current outcomes of this work provide a basis for future investigation in developing a flexible configuration system for the multiple robot work cells.

Warpage Analysis of Different Number Cooling Channels for Dumbbell Plastic Part in Injection Moulding

Warpage deflection is one of the common pitfalls in plastic injection moulding which is always affected the quality and accuracy of the plastic products. It occurs due to the influences of mould temperature during injection moulding process and it is related to the number of cooling system existed in the mould. Therefore, this paper studies the effect of cooling channels on warpage of dumbbell plastic part having different number of cooling channel using Moldflow software. Warpage analysis was run using four and eight cooling channels. Parameters involved in this study are injection time, packing time, melt temperature and mould temperature. The result of warpage from simulation analysis was projected on the graphic having different colour which is presented the actual value of warpage. It is found from warpage simulation result that the maximum warpage for four cooling channels is 1.283mm and the maximum warpage for eight cooling channels is 1.280mm. It shows that the increasing of the number of cooling channel from four to eight channels in the injection mould reduces the warpage deflection about 0.2%. Thus, the result shows that the number of cooling system in the mould plays an important role on the quality of plastic part during injection moulding process.

Improved decision making in lean manufacturing using simulation-based approach

This study aims to enhance the efficacy of decision-making process in ascertaining waste by means of simulation. Waste involving any tasks that are unable to make any value addition to products from the consumers side. Simulation can be deployed to improve the decision-making as well as knowledge of a lean practitioner (LP). To assess the production system and make decision-making more precise, a simulation-based approach was formulated and applied. The results established that production cost and waiting time can be reduced through worker arrangement.

Analysis of Tool Performance during Ball-end Milling of Aluminium Alloy 6061-T6

This article presents the tool wear mechanism when machining Aluminium alloy 6061-T6 with PVD coated carbide under dry cutting condition. Cutting parameters selected were cutting speed, Vc = 115-145 m/min; feed rate fz = 0.15-0.2 mm/tooth and depth of cut, ap = 0.5-0.75 mm. The result showed the tool life of PVD TiAlN ranged from 11 to 97 min. Full factorial approach was employed to exhibit relationship between parameter input and output. From the analysis, cutting speed was found to be the most significant factor for tool performance followed by feed rate and depth of cut. It was also found that most of failure modes occurred were notch wear and flaking near those found near depth of cut line.

Optimization of Milling Parameter for Untreated and Heat Treated Polyetheretherketones (PEEK) Biomaterials

Polyetheretherketones (PEEK) have been widely used as biomaterials for trauma, orthopedics and spinal implants. However, machining of this material poses several challenges such as rough machined surface which can affect the implant functional application. This research attempts to optimize the machining parameter (cutting speed, feed rate and depth of cut) for effectively machining Polyetheretherketones (PEEK) implant material using carbide cutting tools. Apart from optimizing machining parameters, effects of annealing condition on PEEK towards surface qualities are discuss. Response Surface Methodology (RSM) technique was used to evaluate the effects of the parameters and their interaction towards the ability of the optimum conditions. Based on the analysis results, the optimal machining parameter to obtain the smallest surface roughness values were by using spindle speed of 5754 rpm, feed rate of 0.026 mm/tooth and 5.11 mm depth of cut for un-annealed PEEK. As for the annealed PEEK to get the smallest surface roughness values were by using spindle speed of 5865 rpm, feed rate of 0.025 mm/tooth and 2 mm depth of cut.

2308 Effect Cutting Parameters on Surface Roughness during End Milling of AISI D2 Tool Steel

The material of AISI D2 tool steel contains high carbon and chromium alloyed is referred as difficult material to be machining. This research was performed to identify the implications of machining variables in High Speed Machining of milling using material of AISI D2 tool steel with inserted end mill tool. The experiment work was carried out using Box-Behken techniques, a part of response surface methodology (RSM) approach by generating from the Design Expert Software. The effect of milling parameters that are cutting speed, feed rate, and width of cut were studied to evaluate their effects on surface roughness. In this study, the cutting speed, feed rate, and width of cut were in the range of 100-200 m/min, 0.1-0.3 mm/tooth, 0.2mm and 2.0-8.0 mm respectively. This study prove that the parameters that give the most significant to the surface roughness in descending order starting from cutting speed, feed rate and width of cut. The effects of input factors on the response were identified by using analysis of variance ANOVA. The responds of surface roughness then simultaneously optimized. The optimum parameters that yield the best surface roughness are cutting speed of 150 m/min, feed rate of 0.1 mm/min and the width of cut of 8mm that produce the surface roughness of 0.186 μm.

Multi-Objective Optimization Using Box-Behken of Response Surface Methodology for High-Speed Machining of Inconel 718

This study was carried out to investigate how the high-speed milling of Inconel 718 using ball nose end mill could enhance the productivity and quality of the finish parts. The experimental work was carried out through Response Surface Methodology via Box-Behnken design. The effect of prominent milling parameters, namely cutting speed, feed rate, depth of cut (DOC), and width of cut (WOC) were studied to evaluate their effects on tool life, surface roughness and cutting force. In this study, the cutting speed, feed rate, DOC, and WOC were in the range of 100 - 140 m/min, 0.1 - 0.2 mm/tooth, 0.5 - 1.0 mm and 0.2 - 1.8 mm, respectively. In order to reduce the effect of heat generated during the high speed milling operation, minimum quantity lubrication of 50 ml/hr was used. The effect of input factors on the responds was identified by mean of ANOVA. The response of tool life, surface roughness and cutting force together with calculated material removal rate were then simultaneously optimized and further described by perturbation graph. Interaction between WOC with other factors was found to be the most dominating factor of all responds. The optimum cutting parameter which obtained the longest tool life of 60 mins, minimum surface roughness of 0.262 μm and resultant force of 221 N was at cutting speed of 100 m/min, feed rate of 0.15 mm/tooth, DOC 0.5 m and WOC 0.66 mm.