Azwan Iskandar Azmi
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Preferred name
Azwan Iskandar Azmi
Official Name
Azwan Iskandar, Azmi
Alternative Name
Iskandar Azmi, Azwan
Azmi, Azwan Iskandar
Azmi, Azwan I
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Scopus Author ID
57202737293
Researcher ID
G-7831-2012

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Experimental investigation on the microdefects formation due to the electrical discharge coating process: A fractional factorial design

2024-03-07 , Ahmad Fairuz Mansor , Azwan Iskandar Azmi , Zailani Zainal Abidin , Zain M.Z.M.

Electrical discharge coating (EDC) is a well-known technique among researchers for modification of metallic surfaces. This process is capable of producing a hard coating layer, biocompatible and high corrosion resistance at low operating cost. Unfortunately, the process develops unfavourable microcracks and porosity on the substrate surface attributed by heat generation. Thus, in this study, the effect of several parameters to the microdefects' formation was investigated through an experimental work based on fractional factorial design. This work was conducted on a nickel-titanium (NiTi) shape memory alloy by varying the EDC parameters, namely; polarity, discharge duration, peak current, pulse interval, gap voltage and additive Ti nano powder concentration in deionized water (DI water). ANOVA results exhibited that the discharge duration has dominated the microcracks and porosity fraction on the substrate surface due to the impact of high intensity of discharge energy. Although, the Ti nano powder mixed in the DI water had capability to reduce the microcracks formation, the porosity fraction during at high gap voltage setting was elevated with the Ti nano powder mixed.

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Chip morphology and surface integrity in turning AZ31 magnesium alloy under dry machining and submerged convective cooling

2023 , Muhammad Syamil Zakaria , Mazli Mustapha , Azwan Iskandar bin Azmi , Khor Chu Yee

Magnesium alloys have broad applications, including medical implants and the aerospace sector owing to their great density and high strength-to-weight ratio. Dry cutting is a frequent technique for machining this material. However, it always leads to an excessive rise in temperature due to the absence of cooling at the cutting zone, which affects the machined surface integrity and chip morphology. In this study, chip morphology and surface integrity of the AZ31 magnesium alloy were investigated in the turning process using an internal cooling method called submerged convective cooling (SCC) to overcome the absence of cooling in dry cutting. This method can exploit the advantage of the high specific heat capacity of water as a cooling fluid without any reaction between water and magnesium to create a cooling element in the cutting zone. The chip morphologies and surface integrity were analyzed experimentally with varying cutting speeds under SCC and dry cutting. The experimental results revealed that SCC and dry cutting produced saw-tooth or serrated chip formation. The chips produced in dry cutting were continuous, while SCC was short and discontinuous as a result of a severe crack on the back surface of the chip. It was discovered that the grain refinement layer on the machined samples was thinner under SCC turning. SCC machining increased the microhardness of the AZ31 magnesium alloy by 60.5% from 55 HV to 88.3 HV, while dry turning exhibited a 49% increase in microhardness. The result revealed that surface roughness improved by 10.8%, 9.4% and 4.7% for cutting speeds (V) of 120, 180, and 240 m/min, respectively, under the SCC internal cooling. Based on the result obtained, SCC cutting outperformed dry cutting in terms of chip breakability, grain refinement, microhardness, and surface roughness.

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Effect of Build Parameters on Process Energy Consumption and Material Usage in Fused Deposition Modelling Method

2022-01-01 , Omar N.W.Y. , Norshah Aizat Shuaib , Azwan Iskandar Azmi , Mohd Haidiezul Jamal Ab Hadi

Fused deposition modelling (FDM) process is one of popular 3D printing technologies, especially on printing polymer materials for a rapid prototyping. The process is well known for its resource saving, with no tooling cost required and minimum energy demand. However, the challenge is that the process performances are highly influenced by selection of parameters. From literature, consideration on material usage and process energy demand in FDM processes is still limited. This study used an L9 Taguchi orthogonal array design in investigating effect of build orientation, printing speed and layer thickness on process energy consumption and total material usage in FDM processes. The p-values from ANOVA analysis revealed that only layer thickness and build orientation had significant effect on the outputs. In minimising material usage, the strategy is to select the correct build orientation to avoid need of support structure. For reducing energy demand, optimum layer thickness needs to be determined by considering other factors such as mechanical properties and surface roughness. This study provides preliminary findings which will benefit FDM users in using resources efficiently. Further studies are required to complement the findings from the aspects of mechanical and physical properties of the printed products.

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Surface treatment of recycled carbon fibre for interfacial enhancement in reinforced polypropylene product

2020 , A Salleh , Norshah Aizat Shuaib , N W Y Omar , Azwan Iskandar Azmi

Recycled carbon fibre (rCF) is used in various applications as measures to reduce the carbon fibre waste in landfill. This study focuses on using rCF in powder form in injection moulded polypropylene (PP) products. The rCF was treated with 0.5 mol/L and 1.0 mol/L nitric acid. The tensile and flexural properties were evaluated and morphological surface of the samples was characterised using scanning electron microscopy (SEM). As the result, higher concentration of nitric acid increased the tensile strength but leads to lower flexural strength. Apart from that, the environmental assessment using OpenLCA software shows that the addition of RCF filler loading leads to reduction of climate change and acidification potential.

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Chip morphology and surface integrity in turning AZ31 Magnesium alloy under dry machining and submerged convective cooling

2023 , Muhammad Syamil Zakaria , Mazli Mustapha , Azwan Iskandar Azmi , Khor Chu Yee

Magnesium alloys have broad applications, including medical implants and the aerospace sector owing to their great density and high strength-to-weight ratio. Dry cutting is a frequent technique for machining this material. However, it always leads to an excessive rise in temperature due to the absence of cooling at the cutting zone, which affects the machined surface integrity and chip morphology. In this study, chip morphology and surface integrity of the AZ31 magnesium alloy were investigated in the turning process using an internal cooling method called submerged convective cooling (SCC) to overcome the absence of cooling in dry cutting. This method can exploit the advantage of the high specific heat capacity of water as a cooling fluid without any reaction between water and magnesium to create a cooling element in the cutting zone. The chip morphologies and surface integrity were analyzed experimentally with varying cutting speeds under SCC and dry cutting. The experimental results revealed that SCC and dry cutting produced saw-tooth or serrated chip formation. The chips produced in dry cutting were continuous, while SCC was short and discontinuous as a result of a severe crack on the back surface of the chip. It was discovered that the grain refinement layer on the machined samples was thinner under SCC turning. SCC machining increased the microhardness of the AZ31 magnesium alloy by 60.5% from 55 HV to 88.3 HV, while dry turning exhibited a 49% increase in microhardness. The result revealed that surface roughness improved by 10.8%, 9.4% and 4.7% for cutting speeds (V) of 120, 180, and 240 m/min, respectively, under the SCC internal cooling. Based on the result obtained, SCC cutting outperformed dry cutting in terms of chip breakability, grain refinement, microhardness, and surface roughness.

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Roles of eco-friendly non-edible vegetable oils in drilling Inconel 718 through minimum quantity lubrication

2022-09-01 , Safie N.S.S. , Muhamad Nasir Murad , Tan Chye Lih , Azwan Iskandar Azmi , Wan Hamzah W.A. , Danish M.

Metal cutting fluids (MCFs) have played a principal role as coolants and lubricants in the machining industry. However, the wide use of mineral-based oil MCFs has contributed to an adverse effect on humans and the environment. Thus, to overcome the adverse effects of mineral-based oil MCFs, eco-friendly vegetable oil, which is non-edible oil, has been implemented to overcome the issues related to edible oil such as manufacturing costs and food shortages. This study investigated the performance of three different types of non-edible oil, namely castor, neem, and rice bran oils in drilling Inconel 718 using a coated titanium aluminum nitride (TiAlN) carbide drill towards tool life, tool wear, surface integrity, dimensional accuracy, and chip thickness. The MCFs were implemented under the minimum quantity lubrication (MQL) condition at a 50 mL/h flow rate using different cutting speeds (10, 20 m/min) and a constant feed (0.015 mm/rev). The results showed that castor oil minimizes the rapid growth of tool wear and prolongs the tool life by 50% at 10 m/min as compared to rice bran oil. At 20 m/min, castor oil obtained the lowest values of average surface roughness (1.455 µm) and chip thickness (0.220 mm). It was also found that different cutting speeds did not contribute to any significant trend towards hole diameter and roundness for all MCFs. The outstanding performance of castor oil proved that the oil is a potential alternative as an eco-friendly MCF for a cleaner machining environment. Castor oil was determined to be optimum in terms of tool life, tool wear, surface roughness, and chip thickness.

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A study of energy consumption in turning process using lubrication of nanoparticles enhanced coconut oil (NECO)

2017-10-29 , Ahmad Fairuz Mansor , Muhammad Syamil Zakaria , Azwan Iskandar Azmi , Ahmad Nabil Mohd Khalil , Musa N.A.

Cutting fluids play very important role in machining application in order to increase tool life, surface finish and reduce energy consumption. Instead of using petrochemical and synthetic based cutting fluids, vegetable oil based lubricants is safety for operators, environmental friendly and become more popular in the industrial applications. This research paper aims to find the advantage of using vegetable oils (coconut oil) with additional of nano particles (CuO) as lubricant to the energy consumption during machining process. The energy was measured for each run from 2 level factorial experimental layout. Obtained results illustrate that lubricant with enhancement of nanoparticles has capability to improve the energy consumption during the machining process.

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Mechanical properties and environmental assessment of recycled carbon fibre reinforced polypropylene and acrylonitrile butadiene styrene products

2020 , A N Allawi , Norshah Aizat Shuaib , N W Y Omar , Azwan Iskandar Azmi

In this study, the main objective is to determine effect of recycled carbon fibre (RCF) on the mechanical properties of thermoplastics composites and associated environmental impacts. Such study is important to improve the strength of the composites as previous studies are limited on RCF composites, particularly in environmental aspects. In the compounding stage, extrusion process was carried out by using two different thermoplastics i.e. polypropylene (PP) and acrylonitrile butadience styrene (ABS) mixing with RCF. Particle size and weight loading of RCF were chosen as parameters to be studied. Bonding strength between the RCF and thermoplastics matrix was investigated through tensile and flexural properties. Lastly, the assessment of the products was carried out to determine the environmental impacts. Generally, the incorporation of RCF into PP and ABS plastic increases the tensile and flexural properties of the samples. It can be seen that the addition of rCF significantly improves tensile modulus and flexural strength up to 10 wt% filler loading. From the environmental impact assessment, the ABS products have greater impact in all categories. The usage of rCF reduce the amount of plastic hence leads to lower environmental impacts. The product has a potential to be used in mechanical demanding application particularly those require high flexural strength and tensile modulus properties.

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Evaluation of thickness variation of recast layer formation on nitinol from electrical discharge coatings process

2020-06-17 , Ahmad Fairuz Mansor , Azwan Iskandar Azmi , Zain M.Z.M. , Jamaluddin R.

Nitinol is an intermetallic alloy with outstanding properties that suitable as biomaterial. This alloy is capable of recovering to its initial shape after external loading through transformation of the crystalline structure. Unfortunately, excessive exposure of nickel element from this alloy is harmful to human body if released. Thus in this study, the alloy surface was deposited with an oxide layer via electrical discharge coating (EDC) process. The process was performed in deionized water and pure titanium as the electrode. The variation thickness of the recast layer formation was examined by analysing the effects of polarity, gap voltage and erosion depth. Single crater images and electrical waveforms were captured and utilised to elucidate the aforementioned effects. The results exhibited a significant change of layer thickness variation due to different polarity conditions. It was also confirmed that the single crater formation at different polarity was influenced by discharge energy. On other hand, the increase in the open gap voltage can expand the recast layer thickness in lower variation of reverse polarity condition. Finally, erosion depth attributed to a constant layer thickness but in low thickness variation when reverse polarity was employed.

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Parametric evaluation of electrical discharge coatings on nickel-titanium shape memory alloy in deionized water

2020 , Ahmad Fairuz Mansor , Azwan Iskandar Azmi , Mohd Zahiruddin Md. Zain , Roshalliza Jamaluddin

Nickel-titanium shape memory alloy (NiTi) has a unique capacity to restore its initial shape after deformation, which is highly applicable to orthopaedic implantations, especially for the minimization of invasive surgeries. The high nickel content of this alloy can lead to unfavourable effects on the human body upon dissolution; thus, a reliable barrier of coatings on the NiTi surface is required to alleviate the nickel migration and increase its biocompatibility. In this paper, analyses of a titanium oxide layer development on NiTi surface using electrical discharge coating (EDC) process is presented. The recast layer thickness, crater sizes, and surface roughness were characterized based on five parameters; polarity, discharge duration, pulse interval, peak current, and gap voltage. The results show that the discharge duration is the most significant parameter to influence all responses, followed by peak current. The surface characteristics of the EDC substrate is depending on the crater formations and is highly correlated with the discharge energy intensity. As a result, appropriate parametric conditions of the electrical discharge coating process can enhance the NiTi surface for future medical applications, without compromising the shape memory effect.

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