Parameter analysis of copper-nickel-tungsten prepared via powder metallurgy process for electrical discharge machining of polycrystalline diamond

Polycrystalline Diamond (PCD) tools have an outstanding wear resistance. The electric conductivity of PCD caused by the conductive binding material (Cobalt) makes it possible to machine PCD tools with EDM. Electrode used in EDM of PCD must have better porosity, electrical and thermal conductivity. Therefore, this research presents the works in production of Cu-Ni-W electrode by powder metallurgy route. Production of powder metallurgy parts involve mixing of the powder with additives or lubricants, compacting the mixture and heating the green compacts in an Argon gas furnace so the particle bond to each other. Two levels of full factorial with six centre points and two replication technique was used to study the influence of main and interaction effects of the powder metallurgy parameter. There were four factors involved in this experiment. Factor A which is Type of Cu-Ni; Type A and Type B was defined as categorical factor. Factor B in which Composition of W; 5 Wt.%, 15 Wt. % and 25 Wt.%, was defined as numerical factor. Factor C which is the Compaction load; 7, 8 and 9 tonne and Factor D which is Sintering temperature; 635 ℃, 685 ℃ and 735 ℃ were also defined as numerical factor. Optical Microscope, Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) was used to analysed the microstructure and surface morphology of Cu-Ni-W electrode. The best parameter combination to produced better porosity, electrical and thermal conductivity for both Type A and Type B was 5 Wt.% of W, compaction load at 9 tonne and sintering temperature at 735℃. The best response for Type A is 12.65% of porosity, 14.40 IACS% of electrical conductivity and 413.26 W/m.℃ of thermal conductivity. While that, the best response for Type B were 9.36% of porosity, 16.66 IACS% of electrical conductivity and 345.21W/m.℃ of thermal conductivity. From the calculation of Maxwell’s Equation, Type A and Type B had the highest electrical conductivity of 58.48 IACS% and 77.35 IACS% respectively at W content of 5Wt.%. Type A and Type B also had the highest thermal conductivity of 369.86 W/m.℃ and 310.24 W/m.℃ respectively at W content of 5 Wt.%. Besides that, thermal conductivity also increased with the temperature increased until 450℃

Machinability Evaluation of Nanoparticle Enriched in Vegetable-Based-Nanofluids for Machining Process

Vegetable oil had been study to replace mineral based oil as metalworking fluids (MWFs) as it is non toxic, bio-degradable and environmental friendly. Due to vegetable oil’s high viscosity and poor thermal conductivity, some improvement had been applied to vegetable oil such as chemically modified and the addition of additives. The aim of this study to evaluate the machining performance of modified jatropha oil (MJO) with nanoparticle additives of 0.025wt% copper oxide(Cuo) (MJOc) and 0.025wt% hexagonal boron nitride(hBN) (MJOh) as metalworking fluids. The machining performance of MJOc and MJOh were compared with the commercial synthetic ester (SE) through turning process in terms of cutting temperature, surface roughness, tool life and tool wear. The result show that the machining performance of MJOc and MJOh were better compared to SE. In terms of cutting temperature and surface roughness, MJOh shows better maching performance compared to MJOc. In addition, MJOh had same tool life performance with SE which is at cutting length of 6000mm and machining time of 42 minutes. In conclusion, the overall best machining performance is MJOh (MJO+0.025wt% hBN) and has a potential as sustainable MWFs in lubricant market

Analysis Performance of Modified Tamanu Oil Enhanced with Additives as Potential Green Alternative in Metalworking Fluids

Mineral oils have long been utilized in industries as machining lubricants, which contributed to their depletion and hick in price and being non-biodegradable, harmful to the environment, and risk to health. Plant-based oil is more biodegradable, renewable, and environmentally friendly as a green alternative. However, in their crude state, plant-based oils are not up to par with the standard mineral oil used in lubrication in terms of high acidity, low-temperature performance, and oxidative instability. Further chemical modification and adding additives had to be made to improve the oil properties for industrial applications. This study focused on the performance of transesterification of Tamanu plant-based oil with Trimethylolpropane (MTO) and Pentaerythritol (MTOP), which mixed with 1% of Phosphonium Ionic Liquid (PIL) and 10% of Ammonium Ionic Liquid (AIL), producing a series of oil specimens; MTO, MTO+PIL1%, MTO+AIL%, MTOP, MTOP+PIL1%, and MTOP+AIL%. These samples are then subjected to physical analysis to determine the improvement of their properties in terms of kinematic viscosity and viscosity index as well as undergo a four-ball wear test to the determine the tribology aspects of the lubrication in terms of coefficient of frictions and wear scar diameter, in accordance with ASTM standard method. All the results were compared with commercial MWF which synthetic ester (SE) as reference oil. The result of viscosity index reveals that MTOP+PIL1% had the highest value of 178.76. MTO+AIL10% exhibits the lowest average COF (0.061) compared to other MTOs lubricants. Among MTOP, MTOP+PIL1% also had the lowest average COF which is 0.082. The addition of PIL1% to MTO and MTOP lowered the average scar diameter, 730.77 μm and 674.93μm respectively. With the enhanced properties from chemical modification and additives, Tamanu oil can be proposed as a green alternative for developing the metalworking fluid industries in the future

Analysis Performance of Modified Tamanu Oil Enhanced with Additives as Potential Green Alternative in Metalworking Fluids

Mineral oils have long been utilized in industries as machining lubricants, which contributed to their depletion and hick in price and being non-biodegradable, harmful to the environment, and risk to health. Plant-based oil is more biodegradable, renewable, and environmentally friendly as a green alternative. However, in their crude state, plant-based oils are not up to par with the standard mineral oil used in lubrication in terms of high acidity, low-temperature performance, and oxidative instability. Further chemical modification and adding additives had to be made to improve the oil properties for industrial applications. This study focused on the performance of transesterification of Tamanu plant-based oil with Trimethylolpropane (MTO) and Pentaerythritol (MTOP), which mixed with 1% of Phosphonium Ionic Liquid (PIL) and 10% of Ammonium Ionic Liquid (AIL), producing a series of oil specimens; MTO, MTO+PIL1%, MTO+AIL%, MTOP, MTOP+PIL1%, and MTOP+AIL%. These samples are then subjected to physical analysis to determine the improvement of their properties in terms of kinematic viscosity and viscosity index as well as undergo a four-ball wear test to the determine the tribology aspects of the lubrication in terms of coefficient of frictions and wear scar diameter, in accordance with ASTM standard method. All the results were compared with commercial MWF which synthetic ester (SE) as reference oil. The result of viscosity index reveals that MTOP+PIL1% had the highest value of 178.76. MTO+AIL10% exhibits the lowest average COF (0.061) compared to other MTOs lubricants. Among MTOP, MTOP+PIL1% also had the lowest average COF which is 0.082. The addition of PIL1% to MTO and MTOP lowered the average scar diameter, 730.77 μm and 674.93μm respectively. With the enhanced properties from chemical modification and additives, Tamanu oil can be proposed as a green alternative for developing the metalworking fluid industries in the future

Effect of vegetable-based nanofluid enriched with nanoparticles as metalworking fluids during orthogonal cutting process

The growing interest in the usage of vegetable oils as a based fluid for the lubrication industry led to more study on the potential of vegetable oils as MWFs to replace the mineral-based oil due to the environmental benefits such as renewable and biodegradable. In this study, vegetable-based nanofluids were formulated from modified jatropha oils (MJO) mixed with nanoparticle additives copper oxide and activated carbon at different concentration of 0.01, 0.025 and 0.05wt.%. The aim of this study was to evaluate the machining performance of the nanofluids (MJOc1, MJOc2, MJOc3, MJOa1, MJOa2 and MJOa3) compared with the commercial synthetic ester (SE)in terms of cutting temperature and chip thickness. The lathe machine (Harrison alpha 400) was used for orthogonal cutting with the minimum quantity lubrication (MQL) method. Thermal imager camera FLIR T640 used in this experiment to measure the maximum cutting temperature by placing the camera in an axial direction during the machining process. Then, a micrometre (model: Mitutoyo IP 65) used in this experiment to measure the chip thickness while a tool maker measuring microscope used to measure the tool chip contact length after the experimental process. MJO with nanoparticle additions has the potential to replace SE as a long-term metalworking fluid

Effect of Vegetable-Based Nanofluid Enriched with Nanoparticles as Metalworking Fluids During Orthogonal Cutting Process

The growing interest in the usage of vegetable oils as a based fluid for the lubrication industry led to more study on the potential of vegetable oils as MWFs to replace the mineral-based oil due to the environmental benefits such as renewable and biodegradable. In this study, vegetable-based nanofluids were formulated from modified jatropha oils (MJO) mixed with nanoparticle additives copper oxide and activated carbon at different concentration of 0.01, 0.025 and 0.05wt.%. The aim of this study was to evaluate the machining performance of the nanofluids (MJOc1, MJOc2, MJOc3, MJOa1, MJOa2 and MJOa3) compared with the commercial synthetic ester (SE)in terms of cutting temperature and chip thickness. The lathe machine (Harrison alpha 400) was used for orthogonal cutting with the minimum quantity lubrication (MQL) method. Thermal imager camera FLIR T640 used in this experiment to measure the maximum cutting temperature by placing the camera in an axial direction during the machining process. Then, a micrometre (model: Mitutoyo IP 65) used in this experiment to measure the chip thickness while a tool maker measuring microscope used to measure the tool chip contact length after the experimental process. MJO with nanoparticle additions has the potential to replace SE as a long-term metalworking fluid

Nonlinear characterisation of reconfigurable antennas

The lack of references on nonlinearity issue faced in reconfigurable antennas has motivated the work described in this thesis. The nonlinear behaviour is caused by active switches introduced on the radiating structure of the reconfigurable antennas. Depending on the type of active switches deployed on the antenna, the nonlinearity could be severe, which could have serious implications for antenna operation. Thus, the issue of nonlinearity in reconfigurable antennas should not be ignored and nonlinearity measurements should be performed to ensure the nonlinear performance is within an acceptable level. A set of nonlinearity measurements has been identified and performed on the proposed reconfigurable PIFAs. Prototypes are presented with PIN diode and E-PHEMT switches. For the purpose of comparison, measurements were also made with the active switch replaced with a copper bridge for linear interconnection. The nonlinearity performance can be evaluated from the measurement values of third-order intermodulation distortion (IMD3) products, ratio of IMD3 products to carrier, IMD3 products asymmetry, third-order input intercept point (IIP3) and 1-dB gain compression point (P$_1$$_-$$_d$$_B$). The measurements are performed when the antenna is transmitting signals. All measurements are performed on the state-of-the-art, 4-port ZVA67 Rohde & Schwarz VNA. Based on the nonlinearity measurements, it can be concluded that the presence of active switches has compromised the nonlinearity of the reconfigurable antennas. This is evident from the appearance of strong IMD3 products at the frequency of interest. In addition, the power-series-based approximation of 10 dB difference between the measured P$_1$$_-$$_d$$_B$ and IIP3 is shown to be reasonable. Moreover, this work has demonstrated that the ratio of the IMD3 products to carrier does not vary significantly with radiation angles

Modified Tamanu Plant-Based Oil from Pahang Malaysia as biodegradable metalworking fluids

Metalworking fluid (MWF) is a cooling and lubrication agent for the machining process. It is used as a coolant for rapid heat removal and provides a lubrication mechanism at the cutting zone. However, commercial MWFs such as synthetic ester and mineral oil give negative effects on human health and the environment. Therefore, the manufacturing industry should substitute commercial oil with vegetable-based oil. Calophyllum Inophyllum or also known as Tamanu is one of the feasible plant that has abundant oil quantity. In this study, modified Tamanu based oil with Trimethylolpropane ester (MTO) and modified Tamanu based oil with Pentaerythritol ester (MTOP) have been prepared and tested for their physical and tribological properties. Two types of ionic liquids; Phosphonium-based ionic liquid (PIL) and Ammonium-based ionic liquid (AIL) were added to each Tamanu-based oil (MTO and MTOP) to enhance their physical and tribological properties. Physical tests and Fourier Transform Infrared spectrometry (FTIR) were performed on each lubricant samples. The obtained results have shown that there is high viscosity index in MTOP + PIL 1 % and a lower double bond value in MTOP oil. MTOP + PIL 1 % has shown improvement in its tribological properties and can be comparable with commercial oil. Thus, it is suitable to be used as a substitute for commercial metalworking fluid in corresponding to green manufacturing activity

Antecedents and outcomes of brand management from the perspective of resource based view (RBV) theory

Brand management requires greater emphasis on internal factors to increase brand performance. A model of antecedents and outcomes of brand management is developed in this study based on the Resource Based View (RBV) Theory. Top management emphasis on brand, corporate supportive resources and market orientation are identified as crucial internal factors or antecedents for success of brand management. Apart from that, the brand management measurement are expanded in this study with the introduction of three new marketing constructs namely marketing capabilities, innovation and brand orientation as new dimensions in brand management which currently comprised of management related constructs. This study also contributes in the brand management of small and medium enterprise (SMEs) literature as previous studies mainly focused on the brand management for multinational companies or large organizations. One important issue of SMEs is the “internal” brand management which is currently under-researched even though it is critical in brand building and management. Therefore, this research aims to highlight the antecedents and outcomes of brand management in Malaysians’ SMEs based on RBV theory. A comprehensive literature review was done and a conceptual model is proposed in this literature review