This study presents a combined carbon footprint (CF) and environment damage assessment with a cradle-to-gate approach for an ignition coil. The process considers a data flow of product as the phases: raw materials preparation, part processing, final-product finishing, and packaging. The assessment was performed to explore an automotive ignition pencil coil during its developing phase. This study illustrated that a green product problem could be evaluated as a carbon footprint and environmental hazard. By using the conceptual flow to set up the assessment procedure, a product can be decomposed into several material ingredients to specify the input parameters in a Life Cycle Assessment. A total CF of an ignition coil can be investigated individually by each of the materials. The total CF of an ignition pencil coil equal to 0.5254 kgCO2eq was calculated. The insulated filling and copper winding of an ignition coil generated the two most impacting processes in terms of CF (21.83% and 17.50%, respectively). EPS (Environmental Priority Strategies) methodology evaluates the environmental damage of the product in the product design process. As a result, the metal material has a seriously damaging impact on human health and inanimate resources, especially inanimate resources. The total CF generated by the newly devised ignition coil is over 39~62 percent less than a general type one that exists in the current market. The new ignition pencil coil also uses fewer raw materials and therefore reduces environmental damage to the Earth.
Pulse electrochemical mechanical polishing (PECMP) technology is a compound polishing technology by combining the mechanical action of a traditional grinding process and the electrochemical reaction of a pulse electrochemical machining (PECM) like process. Its advantages are low surface roughness, high efficiency, simple equipment, low material removal and more applications. Because a number of processing input variables (voltage activation program, electrolyte composition, etc.) will influence the surface quality of workpiece and productivity, controlling the surface reactions in PECMP requires a carefully designed combination of various processing parameters. In the present work, several typical experiments are investigated to compare the properties of PECMP with that of electrochemical mechanical polishing (ECMP). The experimental results can contribute to optimisation of the processing parameters of PECMP. Analytic methodology for the workpiece surface quality after PECMP is helpful to conduct the processing parameters as well. By comparison, PECMP is proved to be more efficient and have better surface quality than ECMP.
In this study, the anti-loosening characteristics of a precision flank-locking locknut fabricated under various machining processes and tested in different dynamic environments were investigated. The control parameters considered include the tightening torque and thread pitch of the set screw, machining process on the end plane of locknut, and vibration amplitude and frequency of dynamic loading in service, etc. Their sensitivities on the axial force ratio and anti-loosening ratio of the locknut were evaluated using Taguchi method. It was found that the pretension of locknut, the tightening torque and the pitch of set screw, and the machining process of the nut's end plane were the significant control parameters for the anti-loosening performance of the locknut. Moreover, the results of experimental measurements were employed in the regression fit on the performance of the locknut. The regression model was able to predict the anti-loosening ratio with 4.42% average error comparing with the measurements. Furthermore, the optimized design of the locknut through the Taguchi method was able to increase the axial force ratio and anti-loosening ratio by 20.4% and 16.8%, respectively, comparing with standard locknut.
The performance improvement of advanced electronic packaging material is an important topic to meet the stringent demands of modern semiconductor devices. This paper studies the incorporation of nano-alumina powder and thermoplastic elastomer (TPE) into thermoplastic polystyrene matrix to tune the thermal and mechanical properties after injection molding process. In the sample preparation, acetone was employed as a solvent to avoid the powder escape into surrounding during the mechanical mixing in a twin-screw mixer. The pressure and shear force were able to mix the composite with good uniformity in compositions. The samples with different compositions were fabricated using injection molding. The measured results showed that adding 5 wt.% of TPE into the simple polystyrene was able to raise the melt flow index from 12.3 to 13.4 g/10 min while the thermal decomposition temperature remained nearly unchanged. Moreover, the addition of small amount of nano-alumina powder could quickly improve the mechanical property by raising its storage modulus. For example, the addition of 3 wt.% of nano-alumina powder had an increase of 7.3% in storage modulus. Over doping of nano-alumina powder in the composite, such as 10 wt.%, on the other hand, lowered the storage modulus from 2404 MPa to 2069 MPa. The experimental study demonstrated that the tuning in the polystyrene’s thermal and mechanical properties is feasible by composition modification with nano-alumina powder and TPE. The better concentration of the additives should be determined according to the specific applications
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