Advanced Materials Research Vol. 1113

Abstract: In this research, heat treatment is the final finishing process applied on nanocrystalline CoNiFe to improve microstructure for good hardness property. Nanocrystalline CoNiFe has been synthesized using the electrodeposition method. This study investigated the effect of heat treatment at 500°C, 600°C, 700°C and 800°C on electrodeposited nanocrystalline CoNiFe. The heat treatment process was performed in the tube furnace with flowing Argon gas. By changing the heat treatment temperature, physical properties such as phase and crystallographic structure, surface morphology, grain size and hardness of nanocrystalline CoNiFe was studied. The nanocrystalline CoNiFe phase revealed the Face Centered Cubic (FCC) and Body Centered Cubic (BCC) crystal structure. FESEM micrographs showed that the grain sizes of the coatings were in the range of 78.76 nm to 132 nm. Dendrite shape was found in the microstructure of nanocrystalline CoNiFe. The nanocrystalline CoNiFe prepared in heat treatment temperature of 700°C, achieved the highest hardness of 449 HVN. The surface roughness of nanocrystalline CoNiFe heated at 700°C was found to be smaller than other temperatures.

Abstract: The growing population of the world resulting in the demand for shelter and infrastructure, consequently increasing the use of natural resources that can cause problem to the environment and material supply. Ceramic tiles are a waste material that has been studied and shown to have pozzolanic properties. This study focuses on the effect of finer ceramic waste as cement replacement on the compressive strength, strength development and flowability of the mortar. The cement was replaced by ceramic powder from 10% to 40% by weight of cement. The specimens were cast in 50x50x50mm cubes and water curing regime was used until the age of testing. The results of 20% replacement show that finer ceramic powder has the potential to be used as cement replacement material.

Abstract: This research was carried out to investigate the mechanical properties of hybridization composite material which used treated kenaf long fibre with Kevlar reinforcement and polyester as matrix. The purpose of this research is to improve the tensile strength and impact resistance quality of kenaf fibre, so it can be widely used in automotive, military and marine application. From this study, hybrid composites were fabricated by hand lay up and cold press method. The hybrid composites were studied by experimental using Instron Universal Testing Machine according to the standard ASTM D3039. Impact test were conducted using drop tower device according to the standard ASTM D3763. It is clearly observed that the mechanical properties were increased with the addition of weight percentage of woven Kevlar in the kenaf composites. The highest energy was recorded at by hybrid composite in combination of 20 wt% Kevlar. The structure observation of impacted hybrid samples showed that as the impact energy increased, the energy absorbed was also increased. It is found that reinforcing kenaf fibre composite with woven Kevlar can improve mechanical properties of kenaf fibre.

Abstract: Sandwich structures with metal foams core are widely used in various engineering applications due to their special properties of high-strength and high-stiffness to weight ratio when compared to the properties of pure material systems. Sandwich structures have the capability to resist impact loads which make them favorable for energy absorber application. The aim of this research is to investigate the impact properties of aluminium foam sandwiched with glass fibre reinforced plastic (GFRP). Drop weight impact test was conducted using hemispherical impactor tip at velocity of 6.7 m/s by striking the samples with and without face-sheets. The result showed that the GFRP and aluminium foam core sandwich panel exhibited promising energy absorption properties, corresponding to the highest specific energy absorption value observed.

Abstract: This paper studies the effects of binder and filler composition to the strength properties of non-cement polyester grout (NCPG). The binder consisted of unsaturated polyester resin whereas the filler consisted of fine sand and fly ash. The composition of binder-to-filler ratios investigated were 0.43, 0.67, 1, 1.49, and 2.3. The mechanical properties of NCPG were investigated through flowability and compression tests. The test results show that the use of polyester resin combined with fine sand and fly ash produces good quality grout with high flowable rate, rapid setting, self-consolidating and high compressive strength.

Abstract: This research studies the properties of Porous Concrete Paving Blocks (PCPB) with different sizes of coarse aggregate. Coarse aggregate (CA) is the main component in manufacturing PCPB. Three different sizes of coarse aggregate were used; 1) CA 5 – 10 mm as a control, 2) CA 5 – 8 mm and 3) CA 8 – 10 mm. Furthermore, a series of test were conducted such as density, compressive strength, porosity and skid resistance test to determine the properties of the blocks. It was found that the size of coarse aggregate affects the strength and porosity of the blocks. The strength was reduced approximately in the range 5 % to 17 % from the control blocks. However, it is vice versa with porosity result which porosity of the blocks increased in between 5 % to 10 %. This shows that the blocks suitable for use in vehicle area where help in reduce the water ponding on pavement surface and also increased the skid resistance between the vehicle tires and pavement.

Abstract: The low degradability behaviour of plastics is an important environmental problem. The end-use of plastic creates waste-disposal problems as these plastics do not readily or naturally degrade and gives severe effect when plastic-waste requires more time to break down. However, as the bio-polymer industries have advanced, biodegradable plastic is being presented as a high promising solution to the environmental problem over the conventional non-biodegradable plastics. As one of the great innovation products in bio-polymer industries, biodegradable plastic can potentially lessen the volume of solid waste and reduce the need for waste dumping sites. Whilst, biodegradable plastic also offers the outstanding properties to resist the brittleness and resistance towards heat. This paper review the potential of biodegradable plastics made from petrochemical-polymers blended with starch, including polyethylene (PE), polycaprolactone (PCL), polyvinyl alcohol (PVOH) polypropylene (PP) and polyvinyl chloride (PVC).

Abstract: This work studies the performance of HDPE/kenaf biocomposite by varying the kenaf loading from 10 wt% to 50 wt%. Compounding has carried out by using single screw extruder. The result indicates that at 10 wt% of kenaf loading gave the highest tensile and impact strength which are25.32 MPa and 102.25 MPa respectively. Beside, at 10% to 50% of kenaf loading show increasing tensile modulus, flexural modulus and flexural strength with increment of kenaf fiber but decreasing in tensile strength and impact strength.

Abstract: The present study was conducted to investigate the possibility of merging the wick-debinding and sintering of injection-molded ceramic parts into a single-step operation. In this study, the synthesized hydroxyapatite (HAp) feedstock prepared was injection moulded according to ASTM standard C1424-10 to produce green specimens. The green specimens were then debound and sintered through a single step wick-debinding and sintering process by using alumina powder as an embedment agent. The principle of this method is that it carried out at a temperature where the binder is melt, allowing it to flow out of the specimens into pores in the contacting of substrate. Once, the binder is successfully removed from the specimens, sintering process is took place to bond the particle together leading to densification of sintered specimens. From the results, it shows that the binders were successfully removed from the green specimens by capillary suction of the molten binder and single phase of HAp was presented at the sintering temperature of 1000°C.

Abstract: Different types of space holder material (SHM) could be used to produce porous copper by powder metallurgy (PM) route. In this present work, three types of selected SHMs, namely polymethyl methacrylate (PMMA), natrium chloride (NaCl) and potassium carbonate (K₂CO₃) were used in the processing of porous copper. Prior mixing with copper powder, the SHM was characterized by Thermal Gravimetric Analysis (TGA) in order to investigate the decomposition temperature. After the mixture of SHM and copper powder was manually pressed to form a cylindrical shape, sintering process was carried out in a high vacuum furnace, followed by dissolution process. Phase analysis and morphological analyses were carried out by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM), respectively. Results showed that owing to greater decomposition temperature for K₂CO₃ than that of PMMA and NaCl, the porous structure developed exhibited a promising morphology, replicating the shape of the K₂CO₃ particles employed, thus promoting better engineered porous structure to suit the desired applications in thermal management applications (TMAs). Besides, the samples also showed better shape rigidity throughout the processing stage.