Applied Mechanics and Materials Vol. 761

Abstract: Decreasing the effect of temperature, surface roughness and vibration amplitude during turning process will improve machinability. Mathematical model has been developed to predict responses of the surface roughness, temperature and vibration in relation to machining parameters such as the cutting speed, feed rate, and depth of cut. The Box-Behnken First order and second-order response surface methodology was employed to create a mathematical model, and the adequacy of the model was verified using analysis of variance. The experiments were conducted on aluminium 6061 by cemented carbide. The direct and interaction effect of the machining parameters with responses were analyzed. It was found that the feed rate, cutting speed, and depth of cut played a major role on the responses, such as the surface roughness and temperature when machining mild steel AISI 1018. This analysis helped to select the process parameters to improve machinability, which reduces cost and time of the turning process.

Abstract: This paper presents the processes to develop a cost-effective small scale 3-axis CNC milling machine. The designed machine tool consisted of stepper motors, bearing, linear guide, ball screw mounting systems, inverter and electronic controller, in which all of these are assembled together in a form of 3-axis operating system. The machine has a built up with the size of 1000 mm (length) × 1000 mm (width) × 650 mm (long) accompanied with a worktable with a dimension of 300 mm (length) × 300 mm (width) × 20 mm (long), and 24,000 rpm maximum spindle speed. To control the movement of the machine, open source software was utilized with the aid of G-Codes to assign the movement of the CNC axes. From the machining test, the machine was found to be capable to machine a metal work piece with high cutting speed and reasonable accuracy. The machine developed in this study offers efficiency and flexibility in the manufacturing production which enables to reduce capital cost due to the small-scale facility.

Abstract: The main purpose of this project is to design and develop an assisting tool in manufacturing of rattan handicraft. Rattan is a non-timber forest resource which has a variety of functions in the making of handicrafts and furniture. The production of rattan handicraft typically carried out using manual and traditional methods. However, there are some problems to be faced by the craftsman in making the handicrafts such as the time constraints for the creation of products, due to the difficulty in term of the size, and the pain in the hands while making the handicraft products. Therefore, assisting tools or devices in manufacturing of rattan handicraft are needed to solve the problem. The methods used are questionnaire survey, CATIA software for RULA analysis and SolidWork software for FEA analysis.

Abstract: Machining of thermoplastic material poses several challenges due to its low melting temperature and high thermal expansion which directly related to cutting force. Thus, controlling the cutting force and temperature is desirable for machining polyetheretherketone (PEEK). The cutting force is dependent on friction and shearing action produced by the tool. It is indicated the cutting force is significantly affected by tool cutter geometry. This paper aims to control the cutting force by optimizing the cutter geometries especially rake, clearance and helix angle on machining PEEK. The two –flutes of solid carbide ball nose end mills were used to conduct the experiments and the cutting force acquired was measured using piezoelectric dynamometer. Response Surface Methodology (RSM) approach was applied to design and analyse the optimal combination of tool geometry feature for machining PEEK. Based on obtained results, the best optimal values of tool geometry which contribute to minimum of cutting force were 17° rake angle, 26° of helix angle and 10° of clearance angle. The best control of tool geometry ultimately improves the cutting performance and reduces defect caused by high cutting forces.

Abstract: Cellulose based hybrid composites are gaining popularity in the growing green communities. With extensive studies and increasing applications for future advancement, the need for an accurate and reliable guidance in machining this type of composites has increased enormously. Smooth and defect free machined surface are always the ultimate objectives. The present work deals with the study of machining parameters (i.e. spindle speed, feed rate and depth of cut) and their effects on machining performance (i.e. surface roughness and delamination) to establish an optimized setup of machining parameters in achieving multi objective machining performance. Cellulose based hybrid composites consist of jute (a bast fiber) and glass fiber embedded in polyester resins. Response Surface Methodology (RSM) using Box-Behnken Design (BBD) was chosen as the design of experiment approach for this study. Based on that experimental approach, 17 experimental runs were conducted. Mathematical model for each response was developed based on the experimental data. Adequacy of the models were analyzed statistically using Analysis of Variance (ANOVA) in determining the significant input variables and possible interactions. The multi objective optimization was performed through numerical optimization, and the predicted results were validated. The agreement between the experimental and selected solution was found to be strong, between 95% to 96%, thus validating the solution as the optimal machining condition. The findings suggest that feed rate was the main factor affecting surface roughness and delamination .

Abstract: 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.

Abstract: The wear on the cutting edge of the gray cast iron trim cutter die will result in the burr formation on the trimmed blanks. This will increase the rejection rate, and hence, decreasing the efficiency of the production. By applying a wear resistant material, the wear rate on the cutting edge of the die is believed to be minimized. In this paper, the methodology of the experiment on the cladding process using gas metal arc as the heat source, and NiCrBSi-WC as the filler material on gray cast iron substrate is presented. NiCrBSi-WC is chosen as the filler material because of its outstanding wear resistance characteristic. Furthermore, it is a popular choice as a wear resistant material in various types of industry. The purpose of the planned experiment is to maximize the wear resistance of the trim cutting die. It is also a fraction of the case study based on the parts production in the automotive industry in Malaysia.

Abstract: The effect of machining parameters on machining characteristics for aluminium alloy LM6 (Al-Sil2) in Electrical Discharge Machining (EDM) die-sinking is studied. The objective of this project is to determine the relationship between the machining parameters including pulse-on time, pulse-off time, peak current and voltage with the machining characterictics such as Material Removal Rate (MRR), Electrode Wear Rate (EWR) and Surface Roughness (Ra). Copper materials having diameter 15mm was chosen as the electrode tool. Design of experimenent using Taguchi technique was employed to design experimental matrix that was used to optimize the MRR, EWR and Ra. The analysis was done by using the Minitab software version 16. It is found that current and pulse off time significantly affect MRR, EWR and Ra while pulse on time and voltage are less significant in their effect on machining responses. Results show that using Taguchi as a design matrix, the best setting of optimum value for machining parameters to find the required machining responses can be obtained.

Abstract: Studies in urea granulation process using Top Spray Fluidized Bed Granulator (TSFBG) is still limited and requires in-depth research about the effectiveness and influence of droplets to the formation of urea granule (UG). Rate and time interval of spraying technique (Pulse) significantly influence the physical properties of urea granules. Cassava starch dissolves in water was selected as the binder released at various time interval to observe impact of spray droplet on UG size formation. Using Taguchi Method, the study had identified three leading factors contributed to the formation of droplet size namely volume of binder (VOB), time pulse of spraying (TPS) and spraying rate (SR). These factors were then evaluated in terms of the influence on response as signal-to-noise analysis (S/N ratios) from Taguchi to validate UG size in range 2 mm to 4 mm from screening process with respect to the actual experimental data. These results were useful for future experiment reference to determine pressure drop and surface contact during interaction between droplet and urea powder particles using TSFBG to obtain uniform UG size and smooth surface layer with reasonable hardness.

Abstract: This paper presents an experimental investigation on cutting performance in turning of mild steel with application of minimal quantity lubrication (MQL) by using vegetable oils: canola oil, sunflower oil and palm oil. In order to study the effects of MQL on turning process, cutting temperature and flank wear were measured during the turning operations. Cutting temperature was measured using tool work thermocouple while flank wear was observed through SPG video microscope. The measured cutting temperatures and flank wear were also compared to that of dry cutting and water mist cutting. Results showed that among the vegetable oils, palm oil demonstrated highest cooling efficiency, at which reduction of 50 percent in cutting temperature compared to dry cutting. However, it was found out that MQL with canola oil yields the longest tool life. Reasons for such findings are also discussed in the paper.