Influence of pattern coating thickness on porosityand mechanical properties of lost foam casting of Al-Si (LM6) alloy

The combination of Aluminum alloy with lost foam casting (LFC) process is best applied in automotive industry to replace steel components in order to achieve light weight components for reducing fuel consumption and to protect the environment. The LFC process involves process parameters such as the degree of vacuum, foam degradation, expanded polystyrene (EPS) foam density, permeability of foam pattern coatings, pouring temperature, filling velocity, cooling rate, and pressure. The effect of polystyrene foam pattern coating thickness on the porosity and mechanical properties of Aluminum Al-Si LM6 alloy were evaluated experimentally. The coating thickness was controlled by slurry viscosity at range between 18sec to 20sec using Zahn viscosity cup No.5 and the foam pattern was coated up to fifth layer. Aluminum Al-Si (LM6) molten metal was poured into expandable mould and castings were examined to determine porosity distribution, mechanical properties and microscopic observation. Results from X-ray testing reveal the porosity distribution on Aluminum Al-Si LM6 castings is greater at thicker foam pattern coating sample. Meanwhile, the tensile strength of casting decreases when foam pattern coating thickness increases. Microscope observation portray the present of porosity on the casting which shows more gas defects present at thicker foam pattern coating sample. The source of porosity in LFC process is due to air entrainment or the entraining gases from polystyrene foam decomposition during pouring of molten metal. As a conclusion, mechanical strength has inverse relationship with porosity

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

Physical properties of new formulation of hybrid nanofluid-based Minimum Quantity Lubrication (MQL) from modified jatropha oil as metalworking fluid

As a metalworking fluid, vegetable-based crude jatropha oil (CJO) was used in place of petroleum-based oil. The use of petroleum-oil-based metalworking fluids poses significant environmental and health concerns. Furthermore, it has a large amount of free fatty acid (FFA), promoting physical damage. This research targets to substantially evaluate the modified jatropha nanofluids formulation as a metalworking fluid for machining processes. CJO was chemically altered using the esterification and transesterification processes to produce modified jatropha oil (MJO). To make the nanofluids, MJO was mixed with nanoparticles of Hexagonal Boron Nitride (hBN) + Tungsten Disulfide (WS2) and Hexagonal Boron Nitride (hBN) + Titanium Dioxide (TiO2) at a concentration of 0.025 wt.%. The viscosity and acid value of MJO nanofluids were assessed using ASTM standards and compared to a synthetic ester (SE). All the data indicates that the physical attributes improved throughout storage. It is possible to conclude that MJOhw (MJO + 0.025 wt.% hBN + WS2) has the ability as a long-term metalworking fluid for the machining operation. According to the experiment results, MJOhw surpasses non-additive MJO in terms of kinematic viscosity by 5.91% at 40 °C and 15.6% at 100 °C. During a one-month duration of storage time, MJOhw also improve viscosity index (319) by 18.15%. Furthermore,MJOhw has an acid value ranging from 0.34 to 0.58 mg NaOH/g. Finally, the inclusion of additives aids MJO in improving its qualities by 31.1% reduction in acid value and MJOhw demonstrates outstanding lubricating properties across all samples