M. Sayuti

Thermal Investigation of Aluminium – 11.8% Silicon (LM6) Reinforced SiO2-Particles

High performance automotive, aerospace, electronics and other industrial and commercial applications are finding tremendous advantages in using metal matrix composites. The reinforcement is very important because it determines the mechanical properties, cost and performance of a given composite. An excellent in mechanical properties, combined with the ease of formability and low cost makes the application of metal matrix composite of aluminium-11.8% silicon reinforced SiO2 to increase steadily. This paper investigates the interrelationships between thermal properties and reinforcement content, microstructure and hardness of LM6 reinforced SiO2 composites. Specimens were fabricated by casting technique for 5, 10, 15 and 20% weight fractions of SiO2 particulate and mesh of: 65 micron. The experimental results show that the thermal diffusivity and thermal conductivity decreases as SiO2 wt.% of the composite increases and under hardness test, it was found that the hardness value had increased gradually with the increased addition of quartz particulate by weight fraction percentage.

Optimizing the Machining Parameters in Glass Grinding Operation on the CNC Milling Machine for Best Surface Roughness

Glass is one of the most difficult materials to be machined due to its brittle nature and unique structure such that the fracture is often occurred during machining and the surface finish produced is often poor. CNC milling machine is possible to be used with several parameters making the machining process on the glass special compared to other machining process. However, the application of grinding process on the CNC milling machine would be an ideal solution in generating special products with good surface roughness. This paper studies how to optimize the different machining parameters in glass grinding operation on CNC machine seeking for best surface roughness. These parameters include the spindle speed, feed rate, depth of cut, lubrication mode, tool type, tool diameter and tool wear. To optimize these machining parameters in which the most significant parameters affecting the surface roughness can be identified, Taguchi optimization method is used with the orthogonal array of L8(26). However, to obtain the most optimum parameters for best surface roughness, the signal to noise (S/N) response analysis and Pareto analysis of variance (ANOVA) methods are implemented. Finally, the confirmation test is carried out to investigate the improvement of the optimization. The results showed an improvement of 8.91 % in the measured surface roughness.

Effect of Quartz-Silicon Dioxide Particulate on Tensile Properties of Aluminium Alloy Cast Composites

This paper describes an experimental investigation of the tensile properties of quartz-silicon dioxide particulate reinforced LM6 aluminium alloy composite. In this experimental, quartz-silicon dioxide particulate reinforced LM6 composite were fabricated by carbon dioxide sand moulding process with variation of the particulate content on percentage of weight. Tensile tests were conducted to determine tensile strength and modulus of elasticity followed by fracture surface analysis using scanning electron microscope to characterize the morphological aspects of the test samples after tensile testing. The results show that the tensile strength of the composites decreased with increasing of quartz particulate content. In addition, this research article is well featured by the particulate-matrix bonding and interface studies which have been conducted to understand the processed composite materials mechanical behaviour. It was well supported by the fractographs taken using the scanning electron microscope (SEM). The composition of SiO2 particulate in composite was increased as shown in EDX Spectrum and Fractograph.

Mechanical Vibration Technique for Enhancing Mechanical Properties of Particulate Reinforced Aluminium Alloy Matrix Composite

The effects of subjecting solidifying particulate reinforced aluminium alloy matrix composite to various sources of vibration on the resulting casting quality, a mechanical vibration technique for inducing vibration resulting in enhanced mechanical properties, such as impact properties is devised. TiC particulate reinforced LM6 alloy matrix composites are fabricated by different particulate weight fraction of titanium dioxide and microstructure studies were conducted to determine the impact strength and density, respectively. Preliminary works show that the mechanical properties have been improved by using vibration mold during solidification compared to gravity castings without vibration.

Computer Simulation and Experimental Investigation of Solidification Casting Process

Computer simulation is widely used and conventional in manufacturing as a way to improve the manufactured goods quality as at same time plummeting invention costs, development time and scrap. In this study, three-dimensional model have been developed to simulate the filling and the solidification pattern in an aluminum casting with “AnyCasting” software. Using this software, solidification of aluminium 11.8% Si alloy in sand and metal mould was simulated and the results were compared with the experimental results. The solidification time and temperature was experimentally determined from thermocouple located at diverse distances. A data logger is used in experiment to gain the temperature division contour during the process of solidification of the aluminium 11.8% Si alloy. Experiments were set up to legalize the simulation results and it is confirm that the results from the two mould methods be in good agreement and the solidification of cast aluminium alloy using copper mould was much faster compared to the one cast sand mould. From this work it is concluded that simulation using AnyCasting software can be use to initially calculate. The simulation shows result that matches with the experimental data qualitatively and therefore the validation procedure is successful.

Influence of Mechanical Vibration Moulding Process on the Tensile Properties of TiC Reinforced LM6 Alloy Composite Castings

Vibrational moulding process has a remarkable effect on the properties of castings during solidification processing of metals, alloys, and composites. This research paper discusses on the investigation of mechanical vibration mould effects on the tensile properties of titanium carbide particulate reinforced LM6 aluminium alloy composites processed with the frequencies of 10.2 Hz, 12 Hz and 14 Hz. In this experimental work, titanium carbide particulate reinforced LM6 composites were fabricated by carbon dioxide sand moulding process. The quantities of titanium carbide particulate added as reinforcement in the LM6 alloy matrix were varied from 0.2% to 2% by weight fraction. Samples taken from the castings and tensile tests were conducted to determine the tensile strength and modulus of elasticity. The results showed that tensile strength of the composites increased with an increase in the frequency of vibration and increasing titanium carbide particulate reinforcement in the LM6 alloy matrix.

Development of SiO2 Nanolubrication System for better surface Quality, More Power Savings and Less Oil Consumption in Hard Turning of Hardened Steel AISI4140

In recent years, the energy efficiency improvement has become significant due to rapid consumption of worlds energy resources. Particularly in manufacturing industry, hard turning process is one of the most fundamental metal removal processes that require huge power consumption and it could be improved in term of energy usage by many alternatives. At the same time, the improvement in term of machined surface quality is become a need since it would reflect appearance, performance and reliability of the products. As for example in the CNC machining field, one of the solution for this issue is by increasing the effectiveness of the existing lubrication systems as it could improve the machined surface quality, reduce the power required to overcome the friction component in batch production of machining process and reduce the oil consumption. The effectiveness of the lubrication system could be improved by introducing the nanobase lubrication system for much less power consumption as the rolling action of billions units of nanoparticle in the tool chip interface could reduce the cutting forces significantly. In this research work, the possibility of using SiO2 nanobase lubrication system is investigated to reduce the machining power consumption as well as improving surface quality in hard turning process of AISI4140.

Micro-EDM drilling of tungsten carbide using microelectrode with high aspect ratio to improve MRR, EWR, and hole quality

Miniaturized products currently have a lot of applications. This work comprehensively describes electrical discharge machining (EDM) and micro-EDM and compares the types of pulse generators, electrodes and methods for calculating material removal rate (MRR), electrode wear ratio (EWR), overcut and surface roughness for these methods. Various fabrication processes of micro-electrodes are explained as well. Moreover, in this research, experiments were performed with EDM machines to produce through micro-holes in WC–16%Co using a CuW microelectrode that was fabricated on the EDM machine. Fractional factorial design was used to analyze the effects of micro-EDM parameters (voltage, current, pulse-ON time, pulse-OFF time) on the MRR, EWR surface roughness, micro-cracks, migration of material to the workpiece, and overcut. It was discovered that there is a direct relationship between micro-hole surface roughness, the burr-like recast layer at the top surface and material removal rate. The current and capacitor were found to be the most significant factors affecting MRR. Besides, the effect of pulse-ON time on EWR appeared more significant than other parameters. However, the effects of voltage, current, and capacitor seemed more significant than pulse-ON time on the amount of micro-cracks. Various machining conditions produced different amounts of overcut. C, O, and Al migrated to the recast layer at the wall of the micro-holes because aluminum powder was used in the oil-based dielectric. It can be concluded that EDM machines can be used for producing micro-holes.

Characterizing the Effects of Micro Electrical Discharge Machining Parameters on Material Removal Rate during Micro EDM Drilling of Tungsten Carbide (WC-Co)

Micro-dies, molds and miniaturized products can be manufactured using micro EDM process. In this research, EDM machine and on-machine fabricated CuW micro-electrode were utilized to produce the micro holes in WC-16%Co. The effects of voltage, current, pulse ON time, pulse OFF time, capacitor and rotating speed on Material removal rate (MRR) during micro EDM drilling of WC-16% Co was analyzed using fractional factorial design method. ANOVA analysis shows that increasing current, rotating speed, capacitor and decreasing voltage and pulse ON time lead to the amplify in MRR. It was found that out of all the factors, current and capacitor had the most significant effect on MRR, while the effect of capacitor was more than current. Eventually, it can be concluded that micro holes can be produced using EDM machine.

Testing for Green Compression Strength and Permeability Properties on the Tailing Sand Samples Gathered from Ex Tin Mines in Perak State, Malaysia

Permeability and green compression strength are among the important mechanical properties and considered much in the sand casting mould preparation. These molding sand properties play a vital role in determining the optimum moisture content for making green sand casting mould. Tailing sand is the residue mineral from tin extraction, which contains between 94% and 99.5% silica and in abundance in Kinta Valley of state of Perak, Malaysia. In this research work, samples of tailing sands were gathered from four identified ex tin mines located at the Perak State, Malaysia. They were investigated by the standards and testing procedures prescribed by the American Foundrymen Society (AFS). Sand specimens of size Ø50 mm×50 mm in height from various sandwater ratios bonded with 4% clay were compacted on applying three ramming blows of 6666 g each by using a Ridsdale-Dietert metric standard rammer. The specimens were tested for green compression strength using Ridsdale-Dietert universal sand strength machine and permeability number with Ridsdale-Dietert permeability meter. Before the tests were conducted, the moisture content was measured using moisture analyzer. Samples with moisture content ranging from 3 to 3.5% were found to have optimum working range with effective green compression strength and permeability.