The Influence of Graphitization Catalyst Electrode in Electrical Discharge Machining of Polycrystalline Diamond-Finish-ing Condition

Electrical Discharge Machining (EDM) is a non-contact machining process that becomes famous in machining of Polycrystalline Diamond (PCD). The material is typically used as the cutting tools for aerospace and automotive industries. However, low electrical conductivity and high melting temperature of PCD has caused slower EDM process. This investigation purposely designed to investigate the influence of different types of electrode which are Copper (ordinary electrode) and Copper-Nickel (newly proposed graphitization catalyst electrode) on EDM performance of MRR and Ra. Interestingly the newly proposed electrode gave positive impact to the investigated performance indication. Cu-Ni electrode recorded 35% better in MRR than the Cu electrode, though with higher short-circuiting rate. Cu-Ni also provided the lowest Ra value with 10% better than the best Ra produced by Cu electrode. This phenomenon occurred as due to the high interaction between the catalyst materials of nickel and diamond which supported by the qualification data provided in this investigation

Application of Bamboo Composite for Unmanned Aerial Vehicle Rod Structure

Researchers are exploring the use of natural fibers, such as bamboo fibers, as a replacement for synthetic fibers in composite materials due to environmental concerns and rising costs. Bamboo fibers have several benefits, including low cost, biodegradability, light weight, and good mechanical qualities. This study focused on the mechanical and physical characteristics of bamboo fiber composites for drone structures. Tensile tests were conducted, revealing a relatively low tensile strength ranging from 22026.99 to 5474.92 N/m3 compared to carbon fibre composites. The tensile strength was influenced by the composition and ratio of bamboo fibre and epoxy. The density of the bamboo fibre composite ranged from 0.9720 to 0.7790 g/cm3, which is lower than carbon fibre composites. Increasing the bamboo fibre content resulted in a decrease in density

The manufacturing and the application of polycrystalline diamond tools – A comprehensive review

Advanced materials such as titanium alloys and metal matrix composites are extensively used in the aerospace industry and biomedical engineering. They are difficult to machine because of the severe abrasion and high temperature at the tool/chip and tool/workpiece interfaces which cause severe tool wear and premature tool rejection. Compared with conventional cutting tools, polycrystalline diamond (PCD) tools are promising in machining refractory metals and hard-to-machine materials because of the outstanding mechanical properties of PCD. This paper reviewed the manufacturing and application of PCD cutting tools. The researches on manufacturing process of PCD tools and the application in cutting hard-to-machine materials were analysed, and the results and findings were comprehensively discussed. Two most widely used refining methods including abrasive grinding and electrical discharge grinding (EDG) as well as the defects caused by the processes were presented. The wear process of PCD tools in different industrial cutting methods and the wear mechanism of different PCD materials were explained in both micro-scale and macro-scale. Research directions and the trend of the application of PCD cutting tools were introduced

Analysis of worker performances using statistical process control in fish paste otak-otak food industries

This research focuses on the improvement of Small and Medium Enterprises through the used of Process Statistical Control (SPC). An industry that focuses on the fish paste (known as “otak-otak”) production was taken as the case study in this research and the problems analysed are based on the real industrial experiences. The data collection for control charts were recorded for two weeks consisting of working time for each operator. The data were collected in subgroup of 16 with sample size of 5. The collection of data for weight of product was recorded randomly for the whole production line, while data collection of working time of operation was taken randomly from each operator every 30 minutes of the working hour. From this study, there are several problems had been detected in the process that been categories in six element that is people, method, measurement, machine, environment and materials. There were lack of motivation, lack of skill, lack of supervision, manual operation, lack of standard of procedure, waiting time in process, weight-based operator, lack of quality check, not using weight scale, conveyer that sometimes got stuck, spoon for tools, no automation, poor layout arrangement, talking while working, small working space, lack of hygiene, waiting time for material and easily spoiled. The findings can be used as the guideline to the industries for future production improvement. The industries would focus on elimination or reduction of the problems through their innovative solution

Design of the goat/sheep holding cage slaughtering system (cage for animal slaughter): innovations and prospect

The main objective of inventing the goat/sheep holding cage-slaughtering mechanism or cage for animal slaughter was to seek solutions for the slaughtering mechanism from the traditional operation with four to five persons manning it to a one-person operation. The development of this innovation is for Chak Chee Bor Enterprise. This mechanism consists of a goat/sheep holding cage of 1.23m (height) X 1.60m (length) X 0.97m (width). The overall purpose of using this goat/sheep holding cage is to keep the goat/sheep calm, whilst minimizing the danger of unnecessary injury to both the animal and worker. The goat/sheep holding cage-slaughtering mechanism consists of a head latch (neck yoke or head gate) to hold the animal‘s neck and head, and two wooden boards to hold or gently clamp the body of the animal, with the purpose to calm the animal and ensure that it does not move. The round-shaped iron pieces at the end of both sides of the holding cage enable the mechanism to be swung aside or tilted at a 45o angle before the final stage of the ritual. This holding cage-slaughtering mechanism that comes with an adjustable head latch is able to accommodate different sizes of animals

Performance Evaluation of Palm-Olein TMP Ester Containing Hexagonal Boron Nitride and an Oil Miscible Ionic Liquid as Bio-Based Metalworking Fluids / Amiril Sahab Abdul Sani ...[et al.]

Bio-based lubricants from vegetable oils are seen as a great potential alternative to the ever declining petroleum oil sources. Vegetable oils are highly biodegradable and non-toxic, pose good lubricating properties and do not require high production costs. Palm oils as the main renewable oil sources in Southeast Asia are being widely used as cooking oils. Researches have been conducted to expand their potential usage as lubricants for manufacturing applications. In this study, a chemically modified palm olein trimethylolpropane (TMP) ester (MRPO) containing various additives has been tested for their tribological characteristics. Two types of additives; hexagonal boron nitride (hBN) nanoparticles as solid lubricants and phosphonium-based ionic liquid (PIL) as an oil-miscible liquid additive were added into the MRPO to enhance its physical and tribological properties. Four ball wear tests were performed on steel/steel contacts lubricated with each of the lubricant samples. The experimental results presented improved physical properties as well as good antiwear and antifriction performances of the lubricant mixtures compared to the base oil. A minute quantity of PIL (1 wt. %) and hBN nanoparticles (0.05 wt. %) are found to increase the tribological performance of the MRPO, as well as when they are mixed together as lubricant additives into the base oil. The tribological improvements posed by the MRPO+PIL1% revealed better than or comparable results to the conventional synthetic ester and therefore is seen suitable for the use as a new advanced renewable bio-based metalworking fluid for manufacturing activities that corresponds to the energy saving benefits and environmental concerns

Intelligent approach for process modelling and optimization on electrical discharge machining of polycrystalline diamond

Polycrystalline diamond (PCD) is increasingly becomes an important material used in the industry for cutting tools of difficult-to-machine materials due to its excellent characteristics such as hardness, toughness and wear resistance. However, its applications are restricted because of the PCD material is difficult to machine. Therefore, electrical discharge machining (EDM) is an ideal method suitable for PCD materials due to its non-contact process nature. The performance of EDM, however, is significantly influenced by its process parameters and type of electrode. In this study, soft computing technique was utilized to optimize the performance of the EDM in roughing condition for eroding PCD with copper tungsten or copper nickel electrode. Central composite design with five levels of three machining parameters viz. peak current, pulse interval and pulse duration has been used to design the experimental matrix. The EDM experiment was conducted based on the design experimental matrix. Subsequently, the effectiveness of EDM on shaping PCD with copper tungsten and copper nickel was evaluated in terms of material removal rate (MRR) and electrode wear rate (EWR). It was found that copper tungsten electrode gave lower EWR, in comparison with the copper nickel electrode. The predictive model of radial basis function neural network (RBFNN) was developed to predict the MRR and EWR of the EDM process. The prominent predictive ability of RBFNN was confirmed as the prediction errors in terms of mean-squared error were found within the range of 6.47E−05 to 7.29E−06. Response surface plot was drawn to study the influences of machining parameters of EDM for shaping PCD with copper tungsten and copper nickel. Subsequently, moth search algorithm (MSA) was used to determine the optimal machining parameters, such that the MRR was maximized and EWR was minimized. Based on the obtained optimal parameters, confirmation test with the absolute error within the range of 1.41E−06 to 5.10E−05 validated the optimization capability of MSA

Intelligent approach for processmodelling and optimization on electrical dischargemachining of polycrystalline diamond

Polycrystalline diamond (PCD) is increasingly becomes an important material used in the industry for cutting tools of difficult-to-machine materials due to its excellent characteristics such as hardness, toughness and wear resistance. However, its applications are restricted because of the PCD material is difficult to machine. Therefore, electrical discharge machining (EDM) is an ideal method suitable for PCD materials due to its non-contact process nature. The performance of EDM, however, is significantly influenced by its process parameters and type of electrode. In this study, soft computing technique was utilized to optimize the performance of the EDM in roughing condition for eroding PCD with copper tungsten or copper nickel electrode. Central composite design with five levels of three machining parameters viz. peak current, pulse interval and pulse duration has been used to design the experimental matrix. The EDM experiment was conducted based on the design experimental matrix. Subsequently, the effectiveness of EDM on shaping PCD with copper tungsten and copper nickel was evaluated in terms of material removal rate (MRR) and electrode wear rate (EWR). It was found that copper tungsten electrode gave lower EWR, in comparison with the copper nickel electrode. The predictive model of radial basis function neural network (RBFNN) was developed to predict the MRR and EWR of the EDM process. The prominent predictive ability of RBFNN was confirmed as the prediction errors in terms of mean-squared error were found within the range of 6.47E−05 to 7.29E−06. Response surface plot was drawn to study the influences of machining parameters of EDM for shaping PCD with copper tungsten and copper nickel. Subsequently, moth search algorithm (MSA) was used to determine the optimal machining parameters, such that the MRR was maximized and EWR was minimized. Based on the obtained optimal parameters, confirmation test with the absolute error within the range of 1.41E−06 to 5.10E−05 validated the optimization capability of MSA

Development of a Knowledge-Based Energy Damage for evaluating Industrialised Building Systems (IBS) Occupational Health and Safety (OHS) Risk

Malaysia’s construction industry has been long considered hazardous, owing to its poor health and safety record. It is proposed that one of the ways to improve safety and health in the construction industry is through the implementation of ‘off-site’ systems, commonly termed ‘industrialised building systems (IBS)’ in Malaysia, which require fewer workers on�site. This is deemed safer, based on the risk concept of reduced exposure; however, no method yet exists for determining the relative safety of various construction methods, including IBS. This thesis presents a comparative evaluation of the occupational health and safety (OHS) risk presented by different construction approaches, namely IBS and traditional methods. The evaluation involved developing a model based on the concept of ‘argumentation theory’, which helps construction designers integrate the management of OHS risk into the design process. In addition, an ‘energy damage model’ was used as an underpinning framework. Development of the model was achieved through three phases. Phase I involved collection of data on the activities involved in the construction process and their associated OHS risks, derived from five different case studies, field observation and interviews. Knowledge on design aspects that have the potential to impact on OHS was obtained from document analysis. Using the knowledge obtained in Phase I, a model was developed in the form of argument trees (Phase II), which represent a reasoning template with regard to options available to designers when they make judgements about aspects of their designs. Inferences from these aspects eventually determined the magnitude of the damaging energies for every activity involved. Finally, the model was validated by panels of experts (Phase III), and revisions and amendments were made to the model accordingly. The model provides a means of evaluating OHS risk among construction workers, which could help designers understand the extent to which their design decisions may impact on OHS and thereby assist them to reduce the risk to an acceptable level. The development of the risk assessment model represents structured knowledge that designers can draw on when making judgments about OHS risks, in the form of argument trees. The model was categorized into several damaging energies, which provides a way to evaluate the risk from start to finish. The research revealed that different approaches/methods of construction projects carried a different level of energy damage, depending on how the activities were carried out. A study of the way in which the risks change from one construction process to another shows that there is a difference in the profile of OHS risk between IBS construction and traditional methods. For example, the potential gravitational damaging energy for certain activities in the in-situ concrete and masonry method can be removed or reduced by the use of IBS/off�site methods such as the wall panel system and the panellised system. This is compatible ii with other researchers’ claims that IBS/off-site is safer and carries significantly less risk in traditional construction. This thesis contributes to knowledge by suggesting options available to product and process designers that allow them to assess the extent to which their design decisions reduce OHS risk in construction, and offering a more rigorous comparison of the OHS risks in IBS and traditional approaches. It is anticipated that the model may provide a way for designers to integrate process knowledge and awareness of safety and OHS risk variables into design to eliminate or reduce hazards in construction. Keywords: IBS, OHS in construction, knowledge-based energy damage model, off-site constructio

Study on handing process and quality degradation of oil palm fresh fruit bunches (FFB)

The main objective of this study is to determine the relationship between quality of oil palm fresh fruit bunches (FFB) and handling processes. The study employs exploratory and descriptive design, with quantitative approach and purposive sampling using self-administrated questionnaires, were obtained from 30 smallholder respondents from the Southern Region, Peninsular Malaysia. The study reveals that there was a convincing relationship between quality of oil palm fresh fruit bunches (FFB) and handling processes. The main handling process factors influencing quality of oil palm fresh fruit bunches (FFB) were harvesting activity and handling at the plantation area. As a result, it can be deduced that the handling process factors variable explains 82.80% of the variance that reflects the quality of oil palm fresh fruit bunches (FFB). The overall findings reveal that the handling process factors do play a significant role in the quality of oil palm fresh fruit bunches (FFB)