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Friction between cutting tool and workpiece generates heat, which can shorten tool life and impair the quality of machined parts. Thus, the use of appropriate lubricants is required to mitigate these issues. In this research, the use of different weight concentration of graphene nanoparticles (0.1 %, 0.5 % and 1.0 %) to augment commercially available vegetable-based oil, LB3000 was investigated using tribological test. Their performances were evaluated in form of the coefficient of friction, wear scar diameter, kinematic viscosity and thermal conductivity. Higher concentration of graphene was found to be more effective in terms of lowering coefficients of friction, reducing wear scar diameter, and improving kinematic viscosity and thermal conductivity. This study clearly demonstrates that a suitable combination of graphene nanoparticles in oil can improve tribological behaviour as well as lubrication performance. [ABSTRACT FROM AUTHOR]

Electrical discharge coating (EDC) is a well-known technique among researchers for modification of metallic surfaces. This process is capable of producing a hard coating layer, biocompatible and high corrosion resistance at low operating cost. Unfortunately, the process develops unfavourable microcracks and porosity on the substrate surface attributed by heat generation. Thus, in this study, the effect of several parameters to the microdefects' formation was investigated through an experimental work based on fractional factorial design. This work was conducted on a nickel-titanium (NiTi) shape memory alloy by varying the EDC parameters, namely; polarity, discharge duration, peak current, pulse interval, gap voltage and additive Ti nano powder concentration in deionized water (DI water). ANOVA results exhibited that the discharge duration has dominated the microcracks and porosity fraction on the substrate surface due to the impact of high intensity of discharge energy. Although, the Ti nano powder mixed in the DI water had capability to reduce the microcracks formation, the porosity fraction during at high gap voltage setting was elevated with the Ti nano powder mixed. [ABSTRACT FROM AUTHOR]

Natural Fibre Reinforced Plastic Composite material that the Kenaf Fibre are used to reinforce to the polymer matrix to improve its mechanical properties. It is environmentally friendly and low cost as compare to non-biodegradable material. It is also widely used in Aerospace, Automotive and Furniture industry. Drilling process plays an important role in fabrication in these industries. However, some defects often occur on the Natural Fibre Reinforced Plastic Composite during drilling process. The major damage is delamination that are found on the surface of the composite in drilling process. This damage reduces the mechanical properties of the composite. Therefore, the objective of this study is to investigate and minimize the delamination by using Response Surface Methodology (RSM). Cutting speed and feed rate are found significant to delamination in this study. The higher the previous researchers investigate the cutting speed with low feed rate, the lower the delamination. Therefore, the conclusion of this study is high cutting speed with low feed rate improve the mechanical quality of composite. [ABSTRACT FROM AUTHOR]

Drilling is one of the material removal process and recently the working scale has entered the micro level. Micro drill life which is normally predictable in the conventional scale machining, remains uncertain to be defined as the failure mode of the micro-sized tool is completely different from the conventional ones. This research is initiated to investigate the distribution of micro tool life when drilling Titanium Ti-6A1-4V. The purpose of this study is to investigate the tool life performance based selected on cutting parameters; spindle speed, depth of cut, feed velocity and the drilling technique. These parameters were then evaluated using Taguchi method to identify the best parameters’ combination in achieving optimum tool life. The result shows that cutting depth is the most significant factor which influence a micro-tool life. The trend however, remains uncertain throughout the experiment as when the best combination parameters was employed, higher tool life could not be assured. [ABSTRACT FROM AUTHOR]