Applied Mechanics and Materials Vol. 315

Abstract: Surface morphology homogeneity and energy modifications for in situ PVD process are two critical factors to prevent unexpected adhesion failure during machining or service. Unlike during film depositing, there is still much gap to be explored on applying pulsed biasing concepts to the substrate during in situ, to ensure the substrate surface readiness prior to film coating. The purpose of this paper is to study the effects of conventional direct current (DC) and pulse direct current (PDC) applied at substrate bias to the surface energy and crystallite size. Tungsten carbide (WC) cutting tool insert and titanium nitride (TiN) were used as substrate and hard coating respectively. The runs were conducted to compare the bias at DC (-500V) and PDC (-200V, -500V, -800V). The surface energy and crystallite size were characterized through wettability test and X-ray diffraction (XRD) analysis. The applying of PDC on the substrate bias was found to further enhance the characteristics of the surface compared to the conventional DC substrate bias.

Abstract: Remanufacturing operations deal with numerous types of used products and parts. For that reason, any missing parts will lead to the extension of remanufacturing lead-time because searching for the missing parts is time consuming. In order to detect the real-time locations for used parts, this paper proposes the application of RFID technology. A proof of concept RFID system is developed on SISCOM Assembly Cell-200. SISCOM is assumed as a small scale remanufacturing facility. The RFID system middleware is developed using LabVIEW 9 and the database is built using PHP & phpMyAdmin. With the availability of this system, the location of missing parts can be detected and the remanufacturing labor hours can be focused on value added activities.

Abstract: The main purposes and challenges in supply chain management are reducing cost and time. Significantly, factors such as the competition of markets in the globe, limitation of energy, raw and virgin materials, environmental protection crisis and increasing of global population dramatically are causing unprecedented issues for the worldwide supply chains for providing goods and services to customers efficiently and effectively. The sustainability approach for Supply Chain Management (SCM) considers the 6Rs principles in four main stages of the supply chains: Pre-manufacture, Manufacture, Use and Post-use. The use of Multi-Agent System (MAS) prepares the most important requirements of an effective sustainable supply chain. At the same time, this agent-based approach provides reliable and agile systems, which will enable enterprises to accommodate ever changing needs of their customers in the future. In this article, the use of MAS for optimal Sustainable Supply Chain Management (SSCM) is reviewed and the integrated functioning of certain agents resulting in information sharing is also demonstrated. With this idea, an attempt is made to provide a MAS model for the SSCM. In the proposed model, each agent performs a specific function of the organization and shares information with other agents. In order to describe this multi-agent based approach, a simple case study is given to illustrate the sustainable supply chain operations.

Abstract: Hybrid metal matrix composite constitutes a tough metal matrix with reinforcement of at least two ceramic particulates and exhibit superior mechanical and thermal properties. The difficulties in machining metal matrix composites are obtaining good surface finish, consumption of more electrical power, involving excessive cutting forces and greater tool wear as it contain very hard ceramic particulates. This factor restrict the wide spread application of these kind of materials. Hence the study of machining characteristics and the optimization of the cutting parameters are prime importance. In this paper aluminium alloy is taken as metal matrix and the silicon carbide (SiC 10% by wt.) and boron carbide (B₄C 5% by wt.) taken as ceramic reinforcement. This material is fabricated in the form of cylindrical rod using stir casting method. Turning operations are carried out in medium duty lathe using poly crystalline diamond (PCD) cutting tool insert. Taguchis design of L₀₉ orthogonal array is followed selecting three machining factors namely cutting speed, feed and depth of cut at three levels. Optimal cutting conditions are arrived by Signal-Noise ratio method with respect to surface roughness. The results are validated by (ANOVA) analysis of variance and the percentage of contribution of cutting speed, feed rate and depth of cut for better surface finish are determined and it is found that the vital parameter is feed followed by cutting speed and then by depth of cut.

Abstract: Today, in the area of material design conversion coatings play an important role in applications where temperature, corrosion, oxidation and wear come in to play. Manganese Phosphate is used to reduce friction and improve lubrication in sliding components. In this study, Prediction of wear coefficient of uncoated, Manganese Phosphate coated, Manganese Phosphate with oil lubricant AISI D2 steels was investigated using Archards equation. The Surface morphology of Manganese Phosphate coatings was examined by scanning electron microscope (SEM) and Energy dispersive X-ray Spectroscopy (EDX) .The wear tests were performed in a pin on disk apparatus as per ASTM G-99 Standard. The wear loss and wear coefficient were evaluated through pin on disc test using a sliding velocity of 0.35 m/s under normal load of 10 to60 N and controlled condition of temperature and humidity. Based on the results of the wear test, the Manganese Phosphate with lubricant exhibited the lowest average wear coefficient of1.24 X10^-10 and the lowest wear loss 0.37 mm³ under 60 N load.

Abstract: Hydrogen plays an important role recently and recognized by various organizations (public and private) to replace fossil fuel in future transportation applications. Recently, research institutes in Malaysia are the focus of the studies on hydrogen technology in order to drive this energy in transportation applications. Since Hydrogen and fuel cells are viewed as one of the most important energy conversion devices in the future, thus the Ministry of Science, Technology and Innovation (MOSTI) had identified this energy as priority research after solar. Just like normal refueling stations, hydrogen stations and its infrastructure must be planned, designed, and operated in accordance with the properties. Safety consideration of hydrogen system installation and its application can consider as one of the major issues influencing the acceptance of hydrogen for public use. The current methodology of hydrogen production and storage system was surveyed in this paper, and the characteristics of the system as well as their advantages and limitation were reviewed. Besides, this study has investigated and discussed the potential hazards associated with hydrogen refueling facilities such as hydrogen production, storage and dispensing system. These preliminary safety considerations in hazard identifications are intended to figure out the potential hazard and thus analyze the hazard in each of the sub-system before the full quantitative risk assessment take place. Thus, a framework for the entire risk analysis of hydrogen fueling stations was established.

Abstract: Solar energy is a natural resource and can be harnessed to provide clean electricity to hydrogen production system. However, control problems still remain due to the large variety of PV output power with different solar radiation levels. To better investigate about this problem, a model that the PV power plants are integrated with production and storage system such as hydrogen generator, electrolyzer, PV system and hydrogen tank is needed. The focus of the present paper is to develop an integrated simulation model that can be effective and user friendly to predict the dynamic behaviors of a solar powered hydrogen system. The solar irradiance and temperature are the independent variables that act as the input variables to the model. The analyzed results could be used for analyzing the system performance, and also for sizing and designing the system. The integrated model is created by using Matlab Simulink simulation platform which allows the users to define the system specification. The particular information of the system such as power generated by the solar system, volumetric production & etc. can be clearly shown and determined in the simulation platform.

Abstract: This research work was concerned with the evaluation of mechanical properties; flexural strength and impact strength of coconut coir textile composites. The coir fabric reinforcement was in a form of woven and cross ply structure. The two types of laminates orientations for cross-ply structures were 0/90 degrees and 45/-45 degrees. Composites with fibre weight fraction of 30% were prepared by hand lay-up and vacuum bagging technique. Mechanisms of composites failure were examined using scanning electron microscopy (SEM). Results have shown that the woven coir reinforced composites exhibited higher impact resistance and flexural strength (warp woven) compare to cross-ply composites. Moreover, 0/90 degrees orientations demonstrated better strength performance compare to 45/-45 degrees. However, damage propagation on woven composites was found to be larger than cross-ply composites. Normality test of data distribution were evaluated using Minitab software and it was proven that all samples were in a very stable behaviour (p > 0.05). Experimental results were also validated using one way analysis of variance technique (one way-ANOVA) and it revealed there was statistically significant difference (p < 0.05) between all different fabric structures of coir fabric as reinforcement in composite.

Abstract: Geometrical defect plays a significant role to inaccuracy of the cold forging part. Defect will harm the assembly tend to affect the performance of the part. Therefore, it must be detected and minimized it as soon as the manufacturing begins. The paper presents an investigation on the geometrical defect of the cold embossing pin based FEA and physical modeling methods. The study focuses on the effect of distance to the edge (DTE) to bulging geometries. The results of both methods show a good agreement.

Abstract: PCBN cutting tool is widely used in turning process and known as second best cutting tool after Diamond. This study investigates the suitability of PCBN cutting tool to cut variety types of steel. Experimental results for three major parameters which are cutting speed 150, 175 and 200 m/min, depth of cut 0.1, 0.2 and 0.3 mm, and feed 0.1, 0.2, and 0.3 mm/rev were converted into surface roughness analysis to look on the performance of PCBN to cut three different types of steels. The selected work materials of carbon steel AISI 1040, alloy steel AISI 4140 and tool steed AISI D2 were machined in dry tuning process with constant cutting length 50 mm and initial workpiece diameter 40 mm. At the end of this study, it is shown that higher cutting speed produced better surface roughness for AISI 1040 and AISI D2 but worsen the surface of AISI 4140. Low feed value is the most practical parameter to be used to produce fine surface finish using PCBN cutting tool. Fluctuate roughness value produced by increasing depth of cut use in turning parameters and no specific relationship can be concluded between depth of cut and surface roughness value.