Effect of pressure on density, porosity and flexural strength during cold isostatic press of alumina-ysz chromia cutting too

This study presented the effect of pressure on the density, porosity and flexural strength when cold isostatic press (CIP) was applied to compact the ceramic powders in the form of insert cutting tools. Specific composition of alumina (Al2O3) wt.90%,yittria stabilized zirconia (YSZ) wt.10%, chromium oxide(Cr2O3) wt.0.6% and polyethylene glycol (PEG) wt.0.6% were ball milled and hand pressed to form green body of ceramic inserts. These green body were undergone further compaction inside CIP with pressures variation of 200 MPa, 300 MPa, 400 MPa with 30 seconds and 60 seconds pressuring time. The ceramic composts were then sintered at 1440°C for 9 hours before being assessed with density, porosity, Rockwell hardness (HRC) and bending test. The results show that CIP use with 300 MPa parameters with 60 seconds shows the best mechanical properties with relative density 95.5%, porosity 4.5% and HRC 65.5 hardness. Further assessment of microstructure revealed that the particles size distributed evenly along fracture surface with coarse grain and porosity dominant in the certain area

Analysis of surface integrity and formation of material side flow in dry and wet machining of aluminum alloy

This paper presents the surface integrity of aluminum alloy under dry and wet conditions. Bars of aluminum alloy with consistent size have been machined at different cutting speeds and feed rates at very short cutting time. The comparison between dry and wet cutting have been assessed based on the surface integrity, determined by the surface roughness value and observation of surface profiles. The result shows that machining in dry condition produces better surface finish where the coolants did not give a big impact on the surface roughness especially at the higher cutting speed. Further observation at the surface profile of dry cutting shows that more formation of material side flow appeared on the machined surface that could decreased the surface roughness value. Surface generated under bot dry and wet conditions appeared with well-defined and free from other damage such as cracking or tearing

Analysis of Surface Integrity and Formation of Material Side Flow in Dry and Wet Machining of Aluminum Alloy

This paper presents the surface integrity of aluminum alloy under dry and wet conditions. Bars of aluminum alloy with consistent size have been machined at different cutting speeds and feed rates at very short cutting time. The comparison between dry and wet cutting have been assessed based on the surface integrity, determined by the surface roughness value and observation of surface profiles. The result shows that machining in dry condition produces better surface finish where the coolants did not give a big impact on the surface roughness especially at the higher cutting speed. Further observation at the surface profile of dry cutting shows that more formation of material side flow appeared on the machined surface that could decreased the surface roughness value. Surface generated under bot dry and wet conditions appeared with well-defined and free from other damage such as cracking or tearing

Effect of hydraulic pressure on hardness, density, tool wear and surface roughness in the fabrication of alumina based cutting tool

Cutting tools can be considered major industrial necessities as it applied mostly to machine components. Development of self-fabricated cutting tool can facilitate lower machining cost as long as the cutting tool can perform effectively. This paper presents the effect of hydraulic pressure on density, hardness, wear performance and surface roughness during fabrication of the alumina based ceramic cutting tool. Specific raw of alumina powders were ball milled compacted into green body using hydraulic press with different pressures of 6, 7, 8 and 9 tons. These green bodies were sintered at 1700°C in 4 hours soaking time. Hardness and density of sintered bodies were examined in order to correlate the effect of hydraulic pressure on mechanical properties. The samples were further tested into machining with AISI 1045 in order to evaluate their wear performances and surface roughness. The results show that density and hardness increased as the hydraulic pressure increased. The highest pressure of 9 tons demonstrated highest density and hardness of 2.77 g/cm3 and 86.1 HRA respectively. The fabricated cutting tool capable to cut the AISI 1045 steel with the minimum wear rate recorded at 0.0025 mm/s for 9 ton of pressured sample. In terms of failure modes, the cutting tool suffered with abrasive wear and cracks at the edge of tool nose radius. Surface roughness demonstrate minimum 1.24 µm for 7 ton of pressure, which considered high for short time machining process. Overall, the self-fabricated cutting tool capable to cut the steel without catastrophic failure which demonstrated promising results to be improved in the future

Black box modelling and simulating the dynamic indoor air temperature of a laboratory using autoregressive–moving-average (ARMA) model

Mathematical model representing the dynamic indoor air temperature of a building is important for reducing the time and cost required to test any proposed thermal comfort control algorithm and strategy for that building through computer simulation. There are many types of mathematical model, and each type has its strength(s) and weakness(es). An autoregressive-moving-average (ARMA) model, a type of black box model is used to represent the dynamic indoor air temperature behaviour of industrial instrumentation laboratory at Malaysia-Japan international institute of technology (MJIIT), Universiti Teknologi Malaysia (UTM) Kuala Lumpur based on the recorded data from the laboratory and minimal physical characteristics knowledge of the laboratory. The ARMA model?s output developed in this research is compared with the actual data recorded from the laboratory for performance measurement. The obtained result shows that the ARMA model is sufficient for modelling and simulating the dynamic indoor air temperature behaviour of the laboratory

Effect Of Hydraulic Pressure On Hardness, Density, Tool Wear And Surface Roughness In The Fabrication Of Alumina Based Cutting Tool

Cutting tools can be considered major industrial necessities as it applied mostly to machine components. Development of self-fabricated cutting tool can facilitate lower machining cost as long as the cutting tool can perform effectively. This paper presents the effect of hydraulic pressure on density, hardness, wear performance and surface roughness during fabrication of the alumina based ceramic cutting tool. Specific raw of alumina powders were ball milled compacted into green body using hydraulic press with different pressures of 6, 7, 8 and 9 tons. These green bodies were sintered at 1700°C in 4 hours soaking time. Hardness and density of sintered bodies were examined in order to correlate the effect of hydraulic pressure on mechanical properties. The samples were further tested into machining with AISI 1045 in order to evaluate their wear performances and surface roughness. The results show that density and hardness increased as the hydraulic pressure increased. The highest pressure of 9 tons demonstrated highest density and hardness of 2.77 g/cm3 and 86.1 HRA respectively. The fabricated cutting tool capable to cut the AISI 1045 steel with the minimum wear rate recorded at 0.0025 mm/s for 9 ton of pressured sample. In terms of failure modes, the cutting tool suffered with abrasive wear and cracks at the edge of tool nose radius. Surface roughness demonstrate minimum 1.24 μm for 7 ton of pressure, which considered high for short time machining process. Overall, the self-fabricated cutting tool capable to cut the steel without catastrophic failure which demonstrated promising results to be improved in the future

Numerical investigation of flow through porous media using Lattice Boltzmann Method

This work presents a simulation of incompressible viscous flow within a two-dimensional square cavity filled with porous medium. This study aims to analyze the flow in a lid-driven cavity flow with different Reynolds number and porosity values. The Brinkmann-Forcheimer equation was coupled with Lattice Boltzmann formulation to predict the velocity field in the system. The Lattice Boltzmann Method (LBM) which is known as discrete lattice kinetic is chosen to provide solution for Navier-stokes equations. A specific two-dimensional nine-velocity square lattice model (D2Q9 Model) was used in the simulation. It is found that the LBM is an efficient method to reproduce the dynamics of cavity flow and found to reproduce results comparable to previous work

Experimental studies on savonius wind turbine with unidirectional rotor house for high speed application

Air Wheel Generator (AWG) is known as a vertical axis wind turbine with generator for renewable energy have been developed for low and high speed application. Recently, the various shapes of Savonius housing have been studied to improve its rotational speed and coefficient of rotor power. In this paper, Savonius wind turbine with unidirectional Rotor House (RH) for high speed application has been experimental studies to increase the revolution per minute (RPM) of the alternator and charging capability. The experiment on the AWG test stand was set up for different Blade Thickness (BT), t=0.9 mm, 1.2 mm, 1.5 mm, and 2.0 mm where BT that has higher RPM will be the best rotor. The total of 4 test runs of passenger car installed with AWG was conducted using the best BT of the rotor. From the test run conducted on the highway road, the overall functionality of rotor and output voltage have been observed. The apparatus test stand requires verification with actual test run on passenger. On the other word, only the best BT with high RPM will be continued for further test stand for charging capability. Comparison of test stand and test run on passenger car show the blade with a thickness of 0.9mm as the optimum blade thickness. AWG with Blade Guiders had the average speed rated of the alternator is 600 RPM (V belt) and 400 RPM (V Ribbed belt) as a switch is on for air speeds varies from 22.22 to 32.8 m/s. The standard Permanent Magnet Direct Current (PMDC) generator with the same average speed rate was proposed as good combinations for AWG with uni-directional RH. Hence, the conversion of car alternator as the standard permanent magnet that has water proof that may be used also with wind nozzle and lighter rotor material to increase the torque and power of the rotor in the future

The study of light effect on surface roughness of metallic surface by using vision system technique

This paper describes the image processing method which is one of the non-contact method is applied to measure the mean gray value (Ga) used to predict and calculate the value of surface roughness (Ra) on the specimen. All the specimens image are captured in different light source environment exposure which is Red LED light, white fluorescent and yellow bulb by using Omron CCD camera. The captured image of each specimen are processed by using MATLAB software as to calculate Ga value on the defect area of the captured image. By using formulation, the Ga value is then transform into surface roughness value and compared with manually measured surface roughness (Ra) data. It is found that there is significant effect on surface roughness measurement from different light source, which effect the accuracy of the surface roughness reading. The outcome of the study clearly indicates the effectiveness of white fluorescent light to be used as light source for surface roughness measurement for metallic surface