Md. Saidin Wahab

The Effect of Fabric Weave on the Tensile Strength of Woven Kenaf Reinforced Unsaturated Polyester Composite

Natural fibers have gained attention in composite making since they are sustainable, renewable, and environmental friendly. However, there are some drawbacks such as low tensile strength, modulus, and flexural strength compared to industrial synthetic fibers. Various techniques have been used to increase the mechanical properties of the reinforced material to compete with synthetic fibers. This study produces reinforced fabric made from kenaf fibers woven into four different weave patterns. The reason for the use of different weave patterns is to reduce the crimp percentage as it may increase the tensile strength of the fabric. The weave patterns are Twill 4/4, Satin 8/3 and Basket 4/4. Plain 1/1 is used as the benchmark. The dry fabric structure with different weave patterns was optimized using a simulation of WiseTex software. The dry fabrics were infused with unsaturated polyester (UPE) to produce composite panel using vacuum infusion process (VIP). The dry fabric and the composites were tested for tensile strength and compared with the plain 1/1 weave pattern. The results show that the breaking strength of dry fabrics increased when different weave patterns with low crimp percentages were used compared with Plain 1/1. However, in composite form, there is a reduction in the tensile strength of Basket 4/4. The other weave patterns still retain the trend of increment in tensile strength compared with Plain 1/1 weave.

Laser Surface Modification of AISI 1025 Low Carbon Steel using Pulsed Nd:YAG Laser for Enhanced Surface Properties

This paper presents laser surface modification of AISI 1025 low carbon steel for enhance surface hardness properties. An Nd:YAG laser system with pulse mode was used in order to modify 10mm thick plate surface. Three controlled parameters were laser power, pulse duration and overlap percentage which ranged from 100W to 200W, 0.4 to 1.0ms and 50% to 90% respectively. The treated samples was characterised for metallographic study and hardness. Metallographic study was conducted using optical microscope for laser modified layer thickness and grain size. Hardness properties were measured using Vickers indenter. The result show that hardness of laser treated area increased due to fine grain size produced in the laser modified layer. The overlapping rates increase significantly with decreasing laser scanning speed. These findings are important high wear applications.

Fabrication of MMC material for EDM electrode

Electrical discharge machining (EDM) is one of the commonly used nontraditional machining methods to produce die cavities by the erosive effect of electrical discharges. This method is popular due to the fact that a relatively soft electrically conductive tool electrode can machine hard workpiece. However, production cost increase with the complexity of the eroded cavity. Recently, new approach for fabrication of EDM electrodes using rapid prototyping (RP) technology has been investigated with one main objective which is to reduce production cost, due to RP technologys ability to produce three dimensional objects from its CAD data source regardless the complexity. This research focus on fabrication of metal matrix composite (MMC) electrode by mixing copper powder with Al2O3 powder.

Evaluation of FDM Pattern with ABS and PLA Material

Selection of the most suitable Rapid Prototyping (RP) and manufacturing process for a specific part creation is a difficult task due to the development of RP processes and materials. Most current RP processes can build with more than one type of material. The paper presents the evaluation on Acrylonitrile Butadiene Styrene (ABS) and Polylactic acid (PLA) part produced from Fused Deposition Modeling (FDM) as a master pattern for Investment Casting (IC) process. The main purpose of this research is to evaluate the dimensional accuracy and surface roughness for hollow and solid part of FDM pattern for IC process with different layer thickness. The value were taken for both before and after the casting process. Results show that model fabricated with hollow internal pattern structure (ABS material) that produced by low layer thickness is better than other models in terms of its dimensional accuracy (-0.19666mm) and surface roughness (1.41μm). Even though the ABS built part performed better as the model, the PLA build part produces better overall casting result. Final part fabricated with solid pattern (PLA material) that produced by high layer thickness is better than other final parts which its dimensional accuracy (-0.12777mm) and surface roughness (3.07μm).

A Review of Polypropylene Nanoclay Nanocomposites: Preparation, Properties and Applications

This paper presents a review on the preparation, processing, properties and the recent applications of polypropylene-nanoclay nanocomposites. The material has attracted many researchers to explore more about the processing techniques, optimizations, and mainly the potential applications reflecting the advantages of these promising materials. The review consists of preparation of nanocomposites master batch, properties such as mechanical and thermal properties the effects of compatibilizers and clay content, as well as the recent application of these composites. The findings of this review might lead to more curiosity and investigating regarding to the above matters.

Characteristics on Treated Kenaf Fiber Reinforced Polypropylene Composites

Nowadays natural fiber and polymer matrix are being extensively used as alternatives in producing furniture like ceiling, floor and etc. to fulfill society demand instead of environmental friendly and saving cost. The objective of this study is to investigate the effects of maleic anhydride grafted polypropylene (MAPP) as a coupling agent for reinforcement between kenaf fiber (KF) and polypropylene (PP). The ratio of MAPP between 3% and 5% was observed to determine which composition ratio is better. The tensile strength for both 30% KF and 40% KF was treated through the alkali treatment process with 5% sodium hydroxide (NaOH). Kenaf fiber reinforced polypropylene (PP/KF) composites were melt blended and then used hydraulic molding test press machine for characterization to observe their tensile strengths by measuring their threshold. Tensile test was carried out to determine the tensile stresses of the composite at the best composition ratio of kenaf fiber that are 30% KF and 40% KF instead of MAPP ratio. The result shows 40% KF (5% MAPP) lead to better tensile performance compared to 40% KF (3% MAPP), 30% KF (5% MAPP) and 30% KF (3% MAPP). Meanwhile, Scanning electron microscopy (SEM) is used to observe the morphological comparison between untreated KF and treated KF as well as PP/KF. The good interfacial bonding between KF and PP was 5% MAPP rather than 3% MAPP due to the optimum strength received. Overall 5% MAPP with 40% PP/KF had shown the best result compared to others with the estimated tensile strength value of 21.38 MPa.

Characteristics of Cobalt Chromium by Neodymium-doped Yttrium Aluminium Garnet; Nd:Y3Al5O12 (Nd:YAG) Laser Sintering Process

This work reports on the results of an experimental study examining the potential of the selective laser sintering process to produce a layer of specimen by using cobalt chromium molybdenum powder. A 300 W Neodymium-doped Yttrium Aluminium Garnet; Nd:Y3Al5O12 (Nd:YAG) laser machine was used in this laser sintering experiment in order to fabricate the cobalt chromium molybdenum specimen. The effects of the laser parameters such as laser power, scan speed, scan spacing, and pulse rate were investigated in this research, in which, the research started by evaluating sintered samples on a single track and continued with multiple tracks which created a single layer sintered sample. The evaluation of specimen characteristics focused on surface morphology, relative density and dimensional accuracy. There was a set power range and pulse rate applied in the single track test which was 30–75 W of laser power and 100, 150, 200, 250 Hz of pulse rate. The lasers applied in the single layer test were 55, 65, 75 W of laser power, 1, 3, 5 mm/s of scan speed and 0.5, 0.6, 0.7 mm of scan spacing. The result of the laser sintering experiment showed that laser power was inversely proportional to the porosity of the specimen, but directly proportional to the area percentage error of the specimen. While, the scan speed parameter was directly proportional to the porosity of the specimen, but inversely proportional to the area percentage error of the specimen. The purpose of this research was to find successful laser parameter conditions and create a process map for the laser sintering of cobalt chromium molybdenum powder material.

The Effect of Alkali Treatment on Impact Strength of Woven Kenaf Reinforced Unsaturated Polyester Composite Using Vacuum Infusion Process

Nowadays, natural fibres are used in many applications such as automotive, due to its material properties and being environmental friendly. This study is on woven Kenaf reinforced unsaturated polyester focusing on the effect of alkali treatment towards the impact strength of the textile composite. The experiment consists of two different yarn size woven in plain weave and infused using vacuum infusion process into a composite panel. Optic microscopy was used to determine the swelling of fibre, fabrics and composites before and after alkali treatment. The high speed puncture was used to evaluate the impact strength of pure unsaturated polyester and the composite. The results showed that alkali treatment enhanced the impact strength of the composite compared to pure polyester and untreated composite. The swelling of the fibres caused the yarns to expand throughout the thickness and the width of each composite. The gap between the yarns interlacing was reduced due to the expansion of yarns which has increased the covering area of the reinforced material.

Failure Analysis of Conveyor Chain Links: A Case Study

This case study is to investigate the causes of failure of chain system through characterization on the failure component. The failures that occur are relate to welding because this dipping latex industry used customized chain that have to be weld in joining with outer chain links. The analysis revealed that the weld defect such as crater leads the crack propagation and added with cyclic loading that cause the fatigue failure. The fatigue failure occurs due to this generated crack at the outer circumference of the weld within chain attachment and outer chain links plate. This type of defect also can be categories as designing-in defect. Fatigue crack propagation was evident by progressive beach marks and the scanning electron microscopy (SEM) analysis revealed the types of microstructure that resulting at heat affected zone (HAZ). Hardness testing by using Rockwell Tester found the different hardness profile at three areas that are weld metal, base metal and heat affected zone. The maximum hardness values were found at heat affected zone and weld metal. Finite element method (FEM) that is Ansys Workbench was used to review the different size of outer link plate thickness that affected to the stress distribution. It was found that stress can be minimized with increasing the plate thickness.

Laser Cutting Characteristic on the Laminated Carbon Fiber Reinforced Plastics (CFRP) Composite of Aerospace Structure Panel

Carbon fiber reinforced plastic (CFRP) composites as high performance material in aerospace industry. The application of laser technology to cut the CFRP shows promising advantages. Therefore, several cutting parameters such as pulse energy, pulse repetition rate, cutting speed and pulse duration need to be taken into consideration. In this study, the effect of the aforementioned parameters on heat affected zone (HAZ), kerf width and taper angle were evaluated. The results showed that pulse energy and pulse repetition rate gave a significant effect on the cutting characteristic.