Applied Mechanics and Materials Vols. 754-755

Abstract: Modeling of thin film coating is an important work to identify the required characteristic. In general, suitable coating process parameters are very important to find the best characteristics of coating and towards less material usage, reduced trial in experiment and less machine maintenance. In this paper, Response Surface Methodology (RSM) was implemented in modeling TiN coating grain size. N₂ pressure, Argon pressure, and turntable speed were selected as process variables, while the coating grain size as an output response. Significant factors that influence the coating characteristic are determined by using Analysis of Variance (ANOVA) and to develop a polynomial quadratic model. Findings from this study suggested that turntable speed and Argon pressure quadratic term has significant effect to the TiN coating grain size. The result also showed that the actual validation data fell within the 95% prediction interval (PI) and the residual errors percentage was lower than 10%.

Abstract: Form-finding of tensioned fabric structure in the form of Enneper minimal surface has been investigated. Computational form-finding is frequently used to investigate the possible forms of uniformly stressed surfaces. In this study, two parameter of Enneper minimal surface was used in this study are u and v = 0.4 and 1.2. This study provides an alternative choice for engineer to consider the Enneper minimal surface, u = v = 0.4 and 1.2 to be applied in tensioned fabric structure.

Abstract: The inflatable bedpan is designed to provide comfortable, convenient, safe, hygienic, efficient and easy to use to the patients and their caretakers. In order to investigate the suitability thickness of inflatable bedpan for the pressure inflow in bedpan tube, the analysis is done using Catia analysis. The static analysis work is carried out to inflatable bedpan cross section of polyvinyl chloride (PVC) and their relative performances have been observed respectively. The thickness 0.5 mm shows the highest Von Mises Stress which is 21100 kPa compared to 0.8and 1.0 mm thicknesses. The lowest Von Mises Stress observed at thickness 1.0 mm which is 2990 kPa. The less stress obtained can encourage perfect shape of the design. In this paper, by observing the result of static structure analysis obtained, 1 mm is suggested as best thickness to be used as an inflatable bedpan wall because it can withstand more pressure while maintaining its stability.

Abstract: An improved slicing algorithm that uses multiple sets of cutting planes to automatically determine parting curves for 3D parts is proposed. In this algorithm, the sets of cutting planes with their individual roles are simultaneously used to create the slicing profiles, and to extract the intersection points for all the outer and inner loops of the parting curves. The results show that the proposed parting curves overcome many problems inherent in current methods while also making the process fast and effective. The algorithm provides a highly effective solution for handling complicated models that contain free-form surfaces, and can be used by various downstream CAD/CAM systems for industrial mold design.

Abstract: The electronic structure of the perovskite manganites AlMnO₃ cubic crystal was presented. The calculations were made within density functional theory and PBE exchange correlations energy approximation. It was found that the crystal exhibit covalent bonding between Mn and O with superexchange mechanism. At groundstate, AlMnO₃ stabilizes in antiferromagnetic structure with semi metallic like nature at the ground state.

Abstract: The electronic structure of the perovskite manganites LaMnO₃ and La_2/3 Al_1/3 MnO₃ was presented. The calculations were made within density functional theory (DFT) and PBE exchange correlations energy approximation. It was found that inclusion of Al dopants add additional states near the Fermi level and decreasing the resistivity values for all temperature range.

Abstract: The magnetic properties of the perovskite manganites LaMnO₃ (LMO) and La_2/3 Al_1/3 MnO₃ (LAMO) was presented. The calculations were made within density functional theory and generalized-gradient approximation (GGA) exchange correlations energy. It was found that LAMO exhibit magnetic properties and stabilizes in antiferromagnetic structure. However cell magnetization and magnetic moments reduce with inclusion of Al dopant.

Abstract: An innovative and novel technology method of processing called Turbo-Mixing Reactive Precipitation (TMRP) design proposed as an alternative to this current processing or conventional productions of fine precipitated calcium carbonate (nanoPCC) in turbo-mixing conditions. In this paper, the effect of the stirring rate onto morphology, particle sizes and reaction time of the precipitated CaCO₃ particles was discussed. CaCO₃ nanoparticles with an average particle size of approximately 15.75 nm were successfully obtained by stirring rotation speed at 900 rpm. The structural analysis was conducted using a Scanning Electron Microscope (SEM) and a Field Emission Scanning Electron Microscope (FESEM). The results showed that the increasing of the multiple’s impeller stirring rotation speed is in favor of the formation of the spherical vaterite.

Abstract: This study focuses on the analysis of plastic injection moulding process simulation using Autodesk Moldflow Insight (AMI) software in order to correlate between process parameters as an input and warpage as an output for single and dual gates mould design. Nessei NEX 1000 injection moulding machine and P20 mould material details are incorporated in this study on top of Acrylonitrile Butadiene Styrene (ABS) as a moulded thermoplastic material. Coolant inlet temperature, material melt temperature, packing pressure and packing time are selected as a variable parameter. Design Expert software is obtained as a medium for analysis and optimization of input variables in order to minimize the warpage. RSM method as well as Analysis of Variance (ANOVA) has been applied in this study. The results of ANOVA show that some interactions between factors are significant towards warpage existence, which is coolant inlet temperature, material melt temperature and packing pressure. Furthermore, the model created using RSM can be used for warpage prediction and improvement due to a minimum value of error. From this study, the dual gate is the best solution which able to improve the warpage up to 80% instead of single.

Abstract: This paper aims to determine by experiment total stress and pressure of deformation depending on punch stroke and the level of deformation on severe plastic deformation of copper Cu_99.75 by multiaxial cold forging. The deformation process is discontinuous and includes deformation processes that define a cycle of severe plastic deformation. This paper aims to determine the stress and pressure corresponding to the first 12 cycles of severe plastic deformation.