Papers by Author: Khairur Rijal Jamaludin

Abstract: Porous materials with open and interconnected pores are very interesting for biomedical applications as it provides a good base for the formation of bone ingrowth naturally. Besides, it also allows for body fluid transportation through the interconnected network. Therefore, in this work, foam replication method has been used to produce porous SS316L. The SS316L slurries were prepared by ball milling and mechanical stirring method. The polyurethane (PU) foam has been used as a sacrificial template. Sintering process was carried in a high vacuum furnace at 1200°C, 1250°C and 1300°C. The overall results show that increasing the sintering temperature from 1200°C to 1300°C and the using of different slurry mixing methods did not significantly affect the physical and mechanical properties of the porous SS316L produced. The density, porosity percentage and compression strength found for this porous SS316L were in the range of 1.35g/cm3-3g/cm3, 62% - 83%, and 30.6MPa-79MPa respectively. The SEM images also show that the microstructure of this porous SS316L mostly consisted of open and interconnected pores. Therefore, these results are very promising for biomedical implant application.

Abstract: Stainless steel foam has been used for various applications due to their advantages over other materials such as high corrosion resistance, easily availability, and low-cost as well as good mechanical properties. In this work, stainless foam was produced by using foam replication method with different solid loading of SS316L i.e 55 wt%, 60 wt%, 65 wt% and 70 wt% SS316L. The samples were sintered in a vacuum furnace at 1250°C. The sample microstructure was characterized by using scanning electron microscope (SEM) while the elemental component was analyzed by using Energy Dispersive X-ray (EDX). The Archimedes test has been conducted to determine the samples density and porosity. It was found that the best sample is SS316L foam with 65 wt% solid loading with the density and porosity of 1.85 g/cm³ and 76.84% respectively which are similar to the human bone. The sample also has open and interconnected pores.

Abstract: Foam replication method is capable of producing foams with a highly porous structure with adjustable pore dimension, shape and size. In this work, this method has been used to prepare stainless steel 316L foam and sintered at 1200°C, 1250°C and 1300°C in a vacuum furnace. The microstructure and elemental analysis of the sample were examined using scanning electron microscope (SEM) and Energy Dispersive X–Ray (EDX), while the mechanical properties of the samples was determined by using compression test. It was found that the average pore size was in the range of 330µm-350µm. The yield strength and elastic modulus are in the range of 58-66 GPa and 0.46-0.50GPa respectively.

Abstract: Metal foams had been developed years ago by researchers. There were various methods used to produce metal foam such as slurry, compaction, gas entrapment technique and casting methods. In this study, slurry method used to produce SS316L foam with powder compositions 50wt%, 55wt% and 60wt%. Polyethylene Glycol (PEG) and Carboxyl Methyl Cellulose (CMC) were used as binder which was mixed with SS316L powder and distilled water. Polyurethane (PU) foams were impregnated with slurry by pressed out to cover every pores and struts of PU foams. Then, the coated PU foams were dried in the oven for 24 hours at 30°C, followed by sintering process in the vacuum furnace at three different temperatures which were 1200°C, 1250°C and 1300°C. There were Oxygen, Aluminium, Calcium, Silicon, Chromium, Nickel, Ferrous and Molybdenum elements found in the SS316L foams.

Abstract: In this study, waste polyethylene terephthalate (PET) polymer binder systems were used to prepare copper-graphite metal injection molding (MIM) feedstock. A mixer and screw extrusion were used to achieve optimized feedstock, and the rheological properties of the resulting fluids were evaluated using a capillary rheometry to simulate the injection molding process. The solid loadings in the copper-graphite mixes were investigated in the ranges of 51-53% using PET binder system. The effects of shear rate (γ), solid volume fraction (φ) and temperature (T) on the rheological behavior of the copper/graphite MIM feedstocks are discussed.High viscosity trend was notably recorded as shear rate increased relatively. The results indicated that this feedstock system shows dilatant characteristic and lots of further work shall be conducted in attempt to establish this as an ideal binder system.

Abstract: Except for the binder characteristics and molding conditions, the powder loading has a very important effect on the compact distortion. Three types of feedstocks consist of water atomised SS316L powder with 55% waste polystyrene, 35% palm stearin and 10% glycerol were prepared. The powder loading of each feedstocks are 63%, 64% and 65% respectively. Effect of glycerol at different powder loading on rheological properties in term of flowability (n), activation energy (E) and moldability (α) were investigated. It has been observed that all feedstocks possess pseudoplastic flow behavior which is one of the most crucial requirements in MIM process. The addition of glycerol decreases the flowability index while increased the activation energy.

Abstract: To categorize the different patterns of connecting rod based on the extent to which the product is remanufacturable is very challenging because of the existence of various models and wide tolerances. Sometimes it cannot be done due to the improper pattern recognition system. Mahalanobis-Taguchi System (MTS) is a diagnostic method employing Mahalanobis Distance (MD) for recognizing different patterns in multivariate data. The aim of this work is to apply T method-3, a sub-method of MTS, to the big-end diameter of connecting rod to distinguish between two distinct ranges within the remanufacturability process spectrum. Furthermore, the method also categorizes various patterns of connecting rod based on their MD from unit space with graphical illustration. The case study is performed in an automotive industry as well as in a contract remanufacturing environment in Malaysia. The outcome of this work is expected to be the enhancement of robustness in the remanufacturing system on pattern recognition applicable to the company under study. It is expected that the company will experience time and energy savings and improved work quality. The resulting systematic analysis is expected to enable fast decision-making. Finally, this study is expected to invoke among researchers a sense of seriousness in their approach towards various case studies involving the upgrading of the remanufacturing process that will bring Malaysias remanufacturing capability on par with that of other developed countries.

Abstract: Remanufacturing process among industries is relatively new in Malaysia. In USA, Europe, Japan, China and India, remanufacturing is already viewed as a huge business opportunity that significantly stimulates growth in Gross Domestic Product (GDP) and employment. The aim of this paper is to expose all possible causes of failures using the Ishikawa diagram and identify the most significant failures using Failure Mode and Effect Analysis (FMEA) with two Risk Priority Number (RPNs). The cleaning process is both time-consuming as well as the most costly of the entire remanufacturing processes. The case study is performed in an automotive contract remanufacturing environment in Malaysia, specifically the remanufacturing of cylinder heads. This work outcome explores the current situation pertaining to the cleaning process in a real world situation, and attempts to promote among researchers green ideas that will bring Malaysias remanufacturing on par with that of other developed countries.

Abstract: While the concept of remanufacturing is gaining in popularity, in practice the remanufacturing industry in Malaysia is still in its nascent stage, with approximately 32 fields in various industries claiming to be involved in the process. This is an indication for Malaysia to further develop the industry as competing developed countries already view remanufacturing as a huge business opportunity. The aim of this study is to identify and minimize the frequent failures occurring during the dismantling process. Ishikawa diagram is used to identify all possible causes of failures while the Failure Mode and Effect Analysis (FMEA) with two Risk Priority Number (RPNs), identifies the most significant failures. The case study is performed in an automotive industry as well as in a contract remanufacturing environment in Malaysia, specifically pertaining to the dismantling of cylinder heads. The work outcome of this project is expected to be the enhancement of the robustness of DfRem investigations among researchers in real life applications and to provide better solution to a wider variety of industry sectors in a developing country like Malaysia.

Abstract: While the concept of remanufacturing, especially on automotive parts is gaining in popularity, in practice the remanufacturing industry in Malaysia is still in its nascent stage, with approximately 32 fields in various industries claiming to be involved in the process. The Mahalanobis-Taguchi System (MTS) is a diagnostic method employing Mahalanobis Distance (MD) for recognizing different patterns in multivariate data. The aim of this work is to apply T method-3, which is one of the sub-methods under the MTS relating to the main journal diameter of the crankshaft. The method distinguishes between two distinct ranges of acceptable remanufacturing and non-remanufacturing processes. Furthermore, the method also categorizes various patterns of crankshaft based on their MD in unit space. The case study is performed in an automotive industry in Malaysia under a contract remanufacturing environment. The outcome of this work is expected to be the enhancement of the robustness of the remanufacturing system on pattern recognition to the company under study. As a result, the company is expected to save more time and energy in coming with faster decision-making. In addition, the study would provide greater inspiration, especially among researchers in aggressively applying MTS applications to a wider variety of industry sectors especially in the remanufacturing area.