Papers by Author: S. Sulaiman

Abstract: The objective of this work is to evaluate the equivalent plastic strain levels induced by equal channel angular extrusion (ECAE) in an annealed Al-6063 alloy after six passes at a temperature of 200^°C following route A with a constant ram speed of 30 mm/min through a die angle of 90^° between the die channels using the finite element method (FEM). ECAE process is simulated using the DEFORM-3D software through a three-dimensional analysis. Grain refinement is simulated by forcing the element size to zero. It is found that for a very fine mesh the PEEQ converges to 1.046.

Abstract: Electro discharge machining (EDM) is a process that uses an electric sparks to generate the high temperature and melt the workpiece. One of the EDM process is drilling. In EDM drilling, an electro thermal mechanism is introduced between the electrode and work piece to create the hole. The hole size is dependent on the diameters of electrode used during the drilling process. The present study performs Taguchi method to investigate the optimal process parameters for high-speed EDM super drill machine that is used to make a small hole. The workpiece used is made from titanium alloy (Ti-6: ASTM B348 Grade 5) and the copper electrode is 2.0 mm in diameter. In this experiment, the process parameters that were selected to be optimised are: current pulse off, maximum current and standard voltage levels. An orthogonal array L₉ were employed to analyze the hole enlargement and material removal rate (MRR) depending on 2.0 mm diameter hole penetration. The optimum EDM parameters for hole making process was established and verified with the acquired results.

Abstract: Due to the fact that material is being removed from the bulk material, all machining operations have some impact on the resulting surface integrity of the machined components. This paper presents an investigation on surface microhardness on machining of TiC reinforced aluminium LM6 alloy composite using uncoated carbide tool under dry cutting condition. The experiments that were carried out consisted of different cutting parameters based on combination of cutting speed, feed and depth of cut as the parameters of cutting process. The microhardness of machined surface at a range of cutting speed, feed and depth of cut were measured. The results show that the microhardness was generally found to be higher near the machined surface layer than the hardness of the matrix in the bulk material during machining for all cutting condition. Microhardness increases beyond the bulk hardness of material occurred 50 μm below machined surface, and then microhardness starts to decrease and reaches the bulk hardness. The microhardness values increases with increased the feed and depth of cut. The highest microhardness recorded was 68 HV_0.5 when machining at a lower cutting speed of 100 m min^-1, feed of 0.2 mm rev^-1 and depth of cut of 1.0 mm.

Abstract: A simplified model for micro milling process is presented, as well as results on temperature on tool and work piece. The purpose is to investigate on finite element modelling of two flute micro end milling process of titanium alloy, Ti6Al4V with prediction of temperature distribution. ABAQUS/Explicit has been chosen as solver for the analysis. A thermo-mechanical analysis was performed. First model was created by selecting medium carbon steel, AISI1045, as workpiece material for model validation purpose. Second model was created by modifying the workpiece material from AISI1045 to Ti6Al4V. The model consists of two parts which are tungsten carbide micro tool and workpiece. Johnson-Cook law model has been applied as material constitutive properties for both materials due to its severe plastic deformation occur during machining. Prediction on forces was obtained during the analysis. Model validation was done by comparing results published by Woon et al. in 2008. The results showed a good agreement in cutting force. Once this was proved, the same model was then modified to simulate finite element analysis in micro milling of Ti6Al4V. Prediction of temperature distribution of micro end mill of Ti6Al4V was done in relation of different undeformed chip thickness. The findings showed that temperature increases as undeformed chip thickness increases. Temperature distribution of Ti6Al4V and AISI1045 under same machining conditions was compared. Results showed that the highest temperature was concentrated at tool edge for Ti6Al4V.

Abstract: . Amid the fierce rising competition in the market, accelerating the problem solving and decision making process have become major issues in product design especially in conceptual design stage. For years, Theory of Inventive Problem Solving (TRIZ) has been extensively applied in problem solving. In this paper, Analytical Hierarchy Process (AHP) was proposed to strengthen three major steps in TRIZ methodology namely as problem definition, root cause identification and solution generation. The integration was then structured in the form of computer-based system. The integration, application and software in AHP and TRIZ method have been discussed in this paper. This proposed support system not only provided evidence that TRIZ methodologies improved by the support of AHP and also aided the designers in early design phase such as concept, process and material selection.

Abstract: The effects of a rotary slasher with two different shapes of knives (L and Y-shaped) at three cutting speeds (1830, 2066 and 2044 rpm) were studied on percentage of pulverization of sweet potato vine passing through the sieve (< 28 mm²). The results showed that all the treatments were significant at p 0.05 and p 0.01 significance level. The best result was by Y-shaped knife with highest vine pulverized percentage of 82.76 % and a mower speed of 2440 rpm had the finest vine pulverized percentage of 90.48 %. The best performance for interaction effects between knife shapes and speeds of mower was achieved by the Y-shaped knife and a mower speed of 2440 rpm resulting in an average percentage of 92.62 % of pulverized vine.

Abstract: This article introduces a new technique involving concurrent engineering (CE) strategy and analytical network process (ANP) technique to form a ranking methodology as a part of the conceptual design selection (CS). The proposed method is referred as concurrent network (CN). The objective of this study is to simultaneously consider of all features of product elements by implementing CE strategy. Furthermore, CN enables interdependence and interrelationship analysis between product elements by application of ANP. In this study, CN is utilized for a conceptual design of metal matrix composite (MMC) component. The results show that by using CN, all important product parameters can be considered simultaneously during the CDS and the importance weights of manufacturing process parameters and material parameters which are related to MMC component performance are attained.

Abstract: A Finite Element Modeling (FEM) and Simulation was Used to Investigate the Effect of Tool Rake Angle, Cutting Speed and Feed Rate on the Cutting Temperature of Tial6v4 Alloy. the Purpose of this Study was to Find Proper Cutting Parameters for Machining of Titanium Alloy where Cutting Temperature was Lowest. A FEM Based on ABAQUS Software which Involves Jonson-Cook Material Model and Coulomb’s Friction Law was Applied to Simulate an Orthogonal Cutting Process. in this Simulation Work, a Range of Tool Rake Angle from 0° to 10°, a Range of Cutting Speed from 300 m/min to 600 m/min and a Range of Feed Rate between 0.1 Rev/mm and 0.25 Rev/mm were Investigated. the Simulation Results Indicated that Increase in Rake Angle Reduces Cutting Temperature while Increasing Cutting Speed and Feed Rate Increase the Cutting Temperature.

Abstract: At this paper attempts have been made to determine the effects of internal pressure on the reinforced composite pressure vessel. Finite element analysis (FEA) along with the Tsai-Wu failure criterion was utilized to predict the failure pressure of the vessel and the optimum fiber angle orientation. Six layers of E-glass/Epoxy and Graphite/Epoxyfibers have been selected to reinforce the aluminium vessel. Fibers were oriented with six different winding angles of 30⁰, 45⁰, 55⁰, 60⁰, 75⁰ and 90⁰ at asymmetric fiber orientation. The commercial code ABAQUS CAE was employed to simulate the model and analyse the structure. Results were revealed that Graphite/Epoxy has higher strength in comparison with E-glass/Epoxy fiber. Also it was observed that for both composite materials 55⁰fiber angle is the optimum winding angle. Results were compared to the experimental ones and there was a good agreement between them.

Abstract: This paper deals with finite element modeling (FEM) and simulation of machining of titanium alloy and H-13 tool steel. Titanium alloys are very suitable for airframe manufacture and aircraft as H-13 uses forging dies and machined die casting. The machinability of both metals was evaluated by high temperature and tool wear. Finite element simulation was performed with ABAQUS explicit software to predict cutting temperature and stress distribution during metal cutting process. The purpose of this study was evaluation the performance of PCBN cutting tool material on machining of titanium alloy and H-13. It was found that PCBN tool can resistant well against high thermal shocks, high temperature and stress distribution when machining difficult to cut materials. The results can give a better understanding of cutting tool material for metal cutting process.