Special Issue 1(6) 2018
Chief Guest Editor
Dr. Nor Kamaliana Khamis
Dr. Teow Yeit Hann
Jurnal Kejuruteraan (Journal of Engineering) special issues is compilation for two sections. First section is for Centre for Materials Engineering & Smart Manufacturing which serve as forum for articles in field of Material Processing and Advanced Manufacturing. Second section is from selected manuscript from Tuanku Jaafar Conference & Workshop 2017 under theme Governance Towards Sustainable Development. Full length papers, reviews and short communications are welcomed, on subjects such as experimentation (both techniques and data), new theoretical models, commentaries work and letters to the editor.
Table of Contents
|1.||Kesan Pembentukan Tikso terhadap Mikrostruktur dan Sifat Mekanik Aloi Al-Si-Cu-Mg
Saziana Samat*, Mohd Zaidi Omar, Intan Fadhlina Mohamed, Ahmad Muhammad Aziz
Forming of metals in their semi-solid state is one of the options for producing near net shape parts. It can produce a strong and highly reliable product. Al-Si-Cu-Mg casting alloy is commonly used in automotive engine components which is now widely used in the semi-solid processing. The main physical properties of the aluminium alloy and alloying element content such as silicon, copper and magnesium, plays an important role in determining the mechanical properties of the alloy. In this paper, the effect of the formation process of Al-Si-Cu-Mg permanent die casting alloy and the thixoforming process has been investigated towards the evolution of microstructure and mechanical properties. Compound phases, shapes and morphology of the two processes were compared. The porosity effect was examined at permanent die castings and thixoforming process. The result of image analysis showed significant change of the thixoforming process of α-aluminum solid phase structure in spherical shape. Size and morphology, as well as the uniformity of the silicon eutectic phases and intermetallic compound distributions of Al2Cu, Al5Fe Si and Al15(Mn,Fe)3Si2 changed due to the compression during thixoforming process. Thixoforming process of the Al-Si-Cu-Mg alloy exhibit the lowest percentage and microporosity area thus proved that porosity issue significantly reduced during the aluminium alloy solidification process in thixoforming process . The tensile properties of thixoformed alloy improved significantly with its ultimate tensile strength, yield strength, and elongation to fracture at 193MPa, 163MPa and 1.6%,respectively.
Keywords: Semisolid Processing, Thixoforming Process, Cast Alloy, Morphology
|2.||Effect of Rolling on Strength of Friction Stir Welded Joint of Aluminium Alloys
Norfazilah Mohd Selamat, Amir Hossein Baghdadi, Zainuddin Sajuri*, Amir Hossein Kokabi, Syarif Junaid
Friction stir welding (FSW) technique is one of the best options especially for joining dissimilar aluminium alloys. However, there is a limitation to weld thin plate using this method since it produces due to less amount of materials mixing in the stir zone hence result in bad aesthetics of the welding surface. In this study, two different types of aluminium alloys, namely AA6061 and AA1100, were butt-joined by using FSW method. The rotational and transverse speeds of the tool were 1,000 rpm and 100 mm/min, respectively. The friction stir welded samples were subsequently cold rolled to a different thickness reduction percentages of 10, 20, and 40%. From the microscopic observation of the sample’s cross-section, no internal defect was detected at the welding area for both the as-welded joints and the rolled specimens. The tensile strength of FSWed sample was 93 MPa. This was only 80% of welding efficiency as compared to the tensile strength of AA6061 at 116 MPa. The results showed that the tensile strength of the dissimilar joint increased with the increase of the rolling percentage. The welding efficiency of samples after 10, 20, and 40% rolling were 86, 94 and 110%, respectively. However, the total elongation of the sample decreased from 29 to 56% with an increase in the rolling percentage. It is worth to acknowledge that there was no crack or defect observed at the FSW joint after the rolling of 40 % thickness reduction. Furthermore, the fracture location of the rolled FSW joints was near the thermo-mechanically affected zone/heat affected zone (TMAZ/HAZ) and indicated ductile fracture behaviour with evidence of dimples on the fracture surface. In conclusion, reducing the thickness of dissimilar FSW joint aluminium alloys plate by the rolling process is possible without any defect nucleation.
Keywords: Friction stir welding, Rolling; Aluminium alloys; Dissimilar joint; Tensile strength
|3.||Assessing Supply Chain Risk Management Practices in Manufacturing Industries In Malaysia
Nur Farhana Mustaffa, Hawa Hishamuddin*, Nuramila Wahida Mat Ropi, Nizaroyani Saibani, Mohd Nizam Ab Rahman
Effective supply chain management is essential to drive an organisation’s performance through increased productivity. This paper aims to identify the various risk sources that cause supply chain risks to occur in the Malaysian manufacturing industry. In addition, the type and frequency of supply chain risks and discussing the best approach to reduce these risks in the context of the manufacturing industry. A survey method was adopted using a questionnaire to collect the necessary information in order to achieve the aim and objectives of this study. Information was collected from several manufacturing sectors in Malaysia, namely; the automotive, electronics and food sectors. The respondents were people having practical knowledge of risk management, including supply chain managers and supervisors. The survey results were analysed using Statistical Package for the Social Sciences (SPSS) software. The analysis of the results indicated that the primary source that led to the occurrence of supply chain risks was mainly due to the delay in responding to the risks. The associated risks that often occur in the manufacturing industry were also identified, namely, changes in customer demand and increasing raw material prices. In addressing these risks, it was found that communication and the exchange of information were the most important practices and initiatives to help reduce the occurrence of supply chain risks. Accordingly, this study is considered as a pilot study given the small number of respondents. Thus, it can be used as a preliminary guideline for future research work.
Keywords : Risk management; Supply chain; Manufacturing industry; Malaysia
|4.||Two Component Materials in Powder Metallurgy: A Review Paper Focused on the Processing Technique Applied in Powder Metallurgy
Najlaa Nazihah Mas’ood*, Farhana Mohd Foudzi, Abu Bakar Sulong, Norhamidi Muhamad, Intan Fadhlina Mohamed
Processing two materials which have different properties gives significant impact to the industries due to their amazing properties which leads in improving the functionality and reliability of products. Many materials have been investigated in terms of layering, bi-material and also co-injection molding process. The two materials may be metal-metal, ceramic-ceramic and metal-ceramic depending on the capabilities requirement. Several techniques have been discussed in this paper regarding improving the hardness properties, magnetic/nonmagnetic and many more. This paper focused on reviewing the methods that were implemented by researchers based on the bonding techniques of two materials. However, both combination metal-metal and metal-ceramic are the most challenging due to their different properties in terms of thermal expansion. For example, in order to control the coefficient thermal expansion (CTE) for each material, before implementing the required process, dilatometer studies are needed. Such study provides an overview on how to suit the diffusion mechanism between the two materials. The benefits and drawbacks for each method were discussed. According to previous researches, the joining of materials such as M2/17-4PH and 17-4PH/zirconia via co-injection molding process have been successful. Such finding is important to evaluate how good the bonding between the two materials is based on the morphology observation at the interface.
Keywords: Two component injection molding; Two component material; Layering; Bi-material; Powder Metallurgy
|5.||Implikasi Gangguan Pemanduan Dan Keadaan Jalan Terhadap Prestasi Pemandu Dalam Keadaan Simulasi
Iylia Azura Mohd Mohid, Nor Kamaliana Khamis*
Driving activities require drivers to control the vehicle while concentrating on the road. Previous studies show environmental factors as well as secondary task while driving are factors that contribute to the occurrence of the road accidents. Secondary task refers to task other than driving activity. In Malaysia, fatigue is the third contributing factor to road accidents, accounting for 15.7%. This fatigue can disturb the focus and performance while driving the car. The purpose of this study was to compare the effects of driver physiological measurements in two different sessions; i) driving under disturbances and secondary tasks and (ii) driving without interruption. In this study, electroencephalogram (EEG) is used to record physiological responses in terms of brain wave in different driving conditions. A total of 12 participants participated in this experiment using a car simulation. The findings show that there are differences in physiological responses for both driving sessions. Beta Activity shows higher Event-related power modulation values until the end of the drive. In conclusion, the type of disruption during driving and secondary tasks shows different findings on driver performance. This study can provide references to drivers and safety and road supervision agencies involved in taking into account the driver’s physiological effects based on the different driving conditions that affect the safety of road users.
Keywords: Safety; Fatigue; Secondary Task; Psychological measurement; EEG
|6.||A Review on Geometrical Tolerance Applications in The Automotive Industry
Jafri Kassim*, Rizauddin Ramli, Abdul Hadi Azman
This paper presents some of the earlier studies pertaining of analytical methods for tolerance, its effect and applications in the automotive industry. In today’s automotive and aerospace industries, the tolerance process is crucial in the design phase and product development. In the design process, issues such as matches and limits, geometric and tolerance dimensions (GD & T) should be considered by designers to assist manufacturers and installation operators to reduce the cause of failure of critical parts. The impact of failure can destroy some critical parts and reduce the system performance. It is also noted that automotive suppliers for part and components face problems related to the quality due to miscommunication related to tolerance. Quality improvements with various methods have been made by automotive suppliers for part and components to remain competitive and building long-term relationships with automotive manufacturers. Automotive parts suppliers are required to contribute towards improving the overall quality of the car. While empirical studies show that statistical concepts are essential for good and important quality management in tackling the manufacturing process, there is insufficient emphasis on the use of tolerance in quality practices among these suppliers. The impact on manufacturing costs and the methods used will be reviewed as a benchmark for further research to optimize and improve the component reliability. As a result, it can be ascertained that extensive researches have been carried out worldwide focusing on tolerance optimization method for mechanical components in the automotive industry.
Keywords: Geometrical dimensioning and tolerance; Fit and limit; Product development.
|7.||Evidence of Electricity Consumption Lead Climate Change in Malaysia
Yogambigai Rajamoorthy*, Ooi Bee Chen, Subramaniam MunusamyAbstract
The consumption of electricity in Malaysia increase in demand as one of the driving forces of economic development. The main source of electric power generation in Malaysia depends on fossil fuels which lead to air pollution currently and a shortage of natural resources (fossil) in the future if this method continues. Moreover, this will cause a serious problem such as sustainability of energy choice and will harm the environment. This study investigates the relationship between climate variables and electric power consumption in Malaysia. The important climate variables included such as average temperature, average rainfall, forest area, carbon dioxide emission and arable land over a period of 1991 to 2015. Augmented Dickey-Fuller unit root test shows that average rainfall, average temperature, and electrical power consumption stationary at their level. However, forest area, carbon dioxide emission, and arable land stationary after first differences. The result of this study indicates that electric power consumption has a long-run relationship between average temperature and average rainfall. This indicates that electric power consumption has an impact on climate change in Malaysia. These studies also find evidence that unidirectional causality between electric power consumption and climate factors. Overall, the wise consumption of electricity and adopting renewable energy to generate electricity will reduce carbon emission in Malaysia.
Keywords: Energy consumption; Electricity consumption; Climate change; Carbon emission; Global warming
|8.||Reducing Carbon Dioxide Emissions from Malaysian Power Sector: Current Issues and Future Directions
Kazeem Alasinrin Babatunde*, Fathin Faizah Said, Nor Ghani Md Nor, Rawshan Ara Begum
Malaysia’s power generation mix has always been highly reliance on fossil fuels, mainly from natural gas and coal, with the latter expected to grow from 48% in 2015 to 66% of the overall generation by 2023. Meanwhile, there are growing concerns over the increasing share of coal in the generation mix given its enormous emissions potential and energy security in the future. Electricity generation is responsible for the largest share of GHG emissions in Malaysia As the country pursue to become a high-income economy by 2020, increasing energy demand puts pressure on the government to choose cheaper energy sources when renewable energies become too costly. To date, progress in analysing the current situation and identifying effective emissions reduction strategies in the power sector has been very slow. Current government policy is channelled towards resource diversity and energy security without articulating sufficient emissions reduction targets and measures for the sector. The purpose of this study is to characterise the current issues related to CO2 emissions reduction strategies in the power sector, identify promising mitigation measures based on the experiences from other countries and the contemporary research outcomes, and note limitations and emergent policy issues. Achieving 45% CO2 emissions reduction target by 2030 along with high-income economic goal pose unique and enormous challenges for the Malaysia’s economy. For these to be achieved, improving electricity generation efficiency in thermal power plants and implementing a group of emission abatement measures such as emissions trading scheme for efficient decarbonization of the power sector are inevitable.
Keywords: Electricity production; CO2 emissions; Reduction target; Decarbonization; Climate change
|9.||Climate Change Awareness and Adaptations among the Farming and Animal Rearing Communities of the Central Sokoto Close-Settle Zone, North-Western Nigeria
Abubakar Magaji Jibrillah*, Mokhtar Jaafar, Lam Kuok Choy
General consensus almost exists amongst scholars across many fields that climate change is a reality, its impacts are already with us and no part of the world or group of people are immune from its impacts. In facts, during recent decades scholars are busy assessing its impact now and in the foreseeable future. Within the fragile dryland ecosystem of Sokoto in the North-western part of Nigeria, some of the immediate impacts of climate change includes declining rainfall, increasing temperature and extreme weather events such as droughts, severe windstorms, heat waves and flooding among others. These presents some serious threats to both the natural ecosystem and people depending on the ecosystem for their livelihood particularly crop farmers and livestock pastoralists that constitutes over 70% of the inhabitant of the area. Under this kind of situation, the need for increasing awareness about the causes, impacts, mitigation and adaptation to climate change cannot be over emphasised particularly among farmers and herdsmen due to the high sensitivity of their livelihood sources to climate change. Using a semi-structured questionnaire with both open and close ended questions and simple statistical techniques, this research tries to investigate the level of climate change awareness and adaptation strategies among farmers and herdsmen in the Sokoto Close-settled Zone of North-western Nigeria. The result revealed a fair level of awareness of climate change particularly amongst the youth in the area. Some climate change adaptation strategies in the area and their implications were also discussed while recommendations on the way forward provided.
Keywords: Climate change; Awareness; Adaptation; Sokoto close-settle zone
|10.||Comparative Study for Lake Water Remediation: Chemical Coagulation and Electrocoagulation
Teow Yeit Haa*, Chua Siew Fen , Muhammad Faizal Radzi,, Uwendiran Ganasen
Water scarcity worldwide has reached the alarming rate and received the greatest attention. The increasing of pressure attributed by world water demand had inspired researchers on use of alternative water sources such as wastewater, a new norm. However, it is a critical need to find out the proper treatment technique to treat the wastewater. In this study, the reclamation and reuse of lake water (wastewater source) was conducted through chemical coagulation and electrocoagulation processes. Aluminium sulphate Al2(SO4)3 was utilized in this study as the coagulant for chemical coagulation process. The dosage of Al2(SO4)3 was manipulated in the range of 2 mg/L – 8 mg/L to investigate the optimal Al2(SO4)3 dosage which brings to greatest removal of chemical oxygen demand (COD), colour, and turbidity from the collected wastewater sample. Whereas, electrocoagulation process was conducted in a lab-scale electrocoagulation reactor with two parallel monopolar aluminium electrodes. The electrocoagulation operation duration and DC power supply to the electrocoagulation reactor were varied in studying the performance of electrocoagulation process. Results obtained from this study depicted that both chemical coagulation and electrocoagulation processes were attractive for the treatment of lake water. However, chemical coagulation presented greater removal efficiency compared to electrocoagulation where it managed to remove COD, colour, and turbidity up to 93.04%, 93.86%, and 93.98%, respectively at the optimal Al2(SO4)3 dosage of 6 mg/L. Sweep coagulation which comprises the adsorption and entrapment of pollutant particles onto aluminium hydroxides was the major mechanism for flocs formation in chemical coagulation process. Besides, the percentage of removal for electrocoagulation process is due to the applied voltage and operation duration. The percentage removal of COD, colour, and turbidity were increased with the increment of DC power supply voltage and pro-longed the operation duration. Results shown that the highest percent of removal is achieved by electrocoagulation reactor operated at 10 V for 45 min in this study, where the percentage of removal for COD, colour, and turbidity was 73.91%, 92.98%, and 71.44%, respectively.
Keywords: Lake water; Wastewater remediation; Chemical coagulation; Electrocoagulation; Comparative study
|11.||Climate Change Mitigation Options in the Forestry Sector of Malaysia
Asif Raihan*, Mohd Nizam Mohd Said, Sharifah Mastura Syed Abdullah, Rawshan Ara Begum
The Intergovernmental Panel on Climate Change (2013) reported that more than half of the observed increase in global average surface temperature was caused by the anthropogenic increase in Greenhouse gas (GHG) concentrations and other anthropogenic forcings together. Continued emissions of GHGs will cause further warming and changes in all components of the climate system. Thus, limiting climate change will require substantial and sustained reductions of GHG emissions. Deforestation and burning of fossil fuels are the major anthropogenic source of carbon emission in the developing countries including Malaysia. Climate change mitigation options in the forestry sector could play an important role in reducing emissions and improving carbon sequestration. Therefore, this article attempts to identify the potential climate change mitigation options and their characteristics in the forestry sector of Malaysia. The major mitigation options include forest protection and conservation, afforestation, reforestation, sustainable forest management, enhanced natural regeneration, urban forestry, agroforestry, short rotation tropical tree plantations, and use of wood based bio-energy. This article suggests for a comprehensive research on the economic analysis of mitigation options which would be useful to address Malaysia’s emission reduction target in a cost-effective way.
Keywords: Climate change; Mitigation options; Carbon sequestration; Forest sector; Malaysia.