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

Research Output

Filters

10
10
Reset filters

Settings
Now showing 1 - 10 of 10
Thumbnail Image
Publication

Performance study of biocompatible recast layer formation on Ti6Al4V by using electrical discharge coatings

2020-04-01 , Ahmad Fairuz Mansor , Azwan Iskandar Azmi , Zahiruddin M. , Islam M.N.

Long-term implantation of titanium-based alloy, Ti6Al4V can be harmful in human bodies due to the release of aluminium and vanadium elements. Thus, a biocompatible barrier coating can be applied towards corrosion and wear resistance of the implant. In this research, the surface of a biomedical grade of Ti6Al4V was coated with a thin film of biomaterial ceramic by the electrical discharge coatings (EDC) using a pure graphite electrode. Polarity, discharge duration and pulse interval were varied to investigate the formation of recast layer thickness (RLT) on the surface of titanium alloys. RLT was measured from cross-sectioned samples using a high magnification optical microscopy. From the statistical analyses of variance, the response was significantly influenced by the pulse interval, followed with electrode polarity. Additionally, the interaction of polarity to discharge duration and pulse interval also significantly affect the RLT. In order to obtain a more uniform recast layer formation, the process condition should be in reverse polarity with a low setting of pulse interval.

View
Thumbnail Image
Publication

A Review of Surgical Bone Drilling and Drill Bit Heat Generation for Implantation

2022-11-01 , Islam M.A. , Nur Saifullah Kamarrudin , Ruslizam Daud , Mohd Noor S.N.F. , Azwan Iskandar bin Azmi , Zuradzman Mohamad Razlan

This study aims to summarize the current state of scientific knowledge on factors that contribute to heat generation during the bone drilling process and how these aspects can be better understood and avoided in the future through new research methodologies. Frictional pressures, mechanical trauma, and surgical methods can cause thermal damage and significant micro-fracturing, which can impede bone recovery. According to current trends in the technical growth of the dental and orthopedic industries’ 4.0 revaluation, enhancing drill bit design is one of the most feasible and cost-effective alternatives. In recent years, research on drilling bones has become important to reduce bone tissue damage, such as osteonecrosis (ON), and other problems that can happen during surgery. Reviewing the influence of feed rate, drill design, drill fatigue, drill speed, and force applied during osteotomies, all of which contribute to heat generation, was a major focus of this article. This comprehensive review can aid medical surgeons and drill bit makers in comprehending the recent improvements through optimization strategies for reducing or limiting thermal damage in bone drilling procedures used in the dental and orthopedic industries.

View
Thumbnail Image
Publication

Roles of new bio-based nanolubricants towards eco-friendly and improved machinability of Inconel 718 alloys

2020-04-01 , Ali M.A.M. , Azwan Iskandar Azmi , Muhamad Nasir Murad , Mohd Zahiruddin Md. Zain , Ahmad Nabil Mohd Khalil , Norshah Aizat Shuaib

The adverse effects of mineral oil-based metal cutting fluid on environmental sustainability have led to increased industrial concerns. Alternatively, biodegradable lubricants such as vegetable oil has a more positive impact with equivalent performance, but insufficient research on their benefits demands further exploration. This work features extensive experimental investigations on machining of Inconel 718 using novel formulations of coconut bio-based oil with enhanced nanoparticles and coco-amido-propyl-betaine. Bio-based with 0.8 wt% of Al2O3 managed to minimise the rapid growth of tool wear and prolong the tool life by 40.17%. Conversely, bio-based with 0.5 wt% of Al2O3 yielded lower values of cutting force (64.32 N), spindle power (2070 kW), specific cutting energy (6.55 W/mm3), and surface roughness (0.29 μm). The outstanding performance of bio-based nanolubricants contributed to superior machinability efficiency and eco-friendly machining environments.

View
Thumbnail Image
Publication

Thermophysical Properties of Molybdenum Disulfide (MoS2) and Aluminium Oxide (Al2O3) in Bio-based Coconut Oil Hybrid Nanolubricant for Cleaner Metalworking Cutting Fluid Applications

2023-06-01 , Faudzi S.M. , Ahmad Nabil Mohd Khalil , Azwan Iskandar Azmi , Sowi S.A.

Green metalworking fluids have increasingly gained pivotal relevance as environmentally compatible lubricant with equivalent performance since conventional lubricant poses significant threat. This study performs experimental and theoretical discovery on the new approach to metalworking fluid; a bio-based coconut oil nanolubricant with hybrid nanoparticles of Al2O3/MoS2 regarding the thermophysical properties. The colloid was produced by suspending Al2O3 and MoS2 nanoparticles in coconut-based oil at different volumetric ratios of 1:1, 1:2, and 2:1 but equal volumetric concentrations of 0.3 vol%. The thermal conductivity of bio-based lubricants increased up to 4.3% with the addition of hybrid nanoparticles which was ascertained using KD2 Pro thermal analyzer. A contact angle goniometer was used to obtain the water drop profile and the maximum wettability of bio-based hybrid nanolubricant was obtained at 27.76° (Al2O3:MoS2 (1:1)) which indicates that incorporating both nanoparticles into the base system improved lubricant spreadability. The kinematic viscosity was evaluated through the viscometer and hybrid nanofluid possessed a remarkable increase in viscosity index of at least 49.6% (Al2O3:MoS2 (2:1)) among other samples. The stability test revealed that the nanolubricant (Al2O3:MoS2 (1:1)) was more stable than others. The experimental outcomes showed that the ratio of hybrid nanoparticles in base fluid has a significant role in enhancing thermophysical properties.

View
Thumbnail Image
Publication

Electrical discharge coating of NiTi alloy in deionized water

2021-01-01 , Jamaluddin R. , Tan Chye Lih , Roshaliza Hamidon , Ahmad Fairuz Mansor , Azwan Iskandar Azmi

Shape memory alloys, specifically nickel-titanium (NiTi), exhibit excellent technical properties that suited them for biomedical applications. However, the release of nickel ions into human body is a drawback because it results in severe adverse health effects as well as degrades the biocompatibility of the alloys. In this work, surface modification through adaptation of electrical discharge machining was used to develop a deposition layer of titanium oxide on NiTi alloy surface. The adaptation was through electrical discharge coatings (EDC) parameters such as polarity, gap voltage, and erosion depth that were set up to study their effects on the experimental performance. The experiment was parameterized by implementing 2 level of full factorial design with ANOVA analysis to measure the surface roughness of that machined surface. One-factor-at-a-time, OFAT method is applied for XRD analysis by adopting the previous parameters approach. The EDC process was aided with deionized water and pure titanium rod as the dielectric fluids and electrodes, respectively. It was determined that the high level of gap voltage provided some major constituents on the surface of NiTi alloy based on XRD analysis. As apparent, this substantiated the presence of the tool materials and their oxide layer phases. The interaction of polarity and gap voltage also indicated a significant effect towards the surface roughness.

View
Thumbnail Image
Publication

Effects of machining conditions on the specific cutting energy of carbon fibre reinforced polymer composites

2017-10-29 , Azwan Iskandar Azmi , Syahmi A. , Naquib M. , Tan Chye Lih , Ahmad Fairuz Mansor , Khalil A.

This article presents an approach to evaluate the effects of different machining conditions on the specific cutting energy of carbon fibre reinforced polymer composites (CFRP). Although research works in the machinability of CFRP composites have been very substantial, the present literature rarely discussed the topic of energy consumption and the specific cutting energy. A series of turning experiments were carried out on two different CFRP composites in order to determine the power and specific energy constants and eventually evaluate their effects due to the changes in machining conditions. A good agreement between the power and material removal rate using a simple linear relationship. Further analyses revealed that a power law function is best to describe the effect of feed rate on the changes in the specific cutting energy. At lower feed rate, the specific cutting energy increases exponentially due to the nature of finishing operation, whereas at higher feed rate, the changes in specific cutting energy is minimal due to the nature of roughing operation.

View
Thumbnail Image
Publication

Black box modelling of infrared drying system for herbs dehydration

2022-01-01 , Mohd Saifizi Saidon , Mohd Muqri Syahmi Sulong , Wan Azani Wan Mustafa , Azwan Iskandar Azmi , Norawanis Abdul Razak , Muhammad Faris Fauzi

This study focused on development of infrared dryer system for Orthosiphon Stamineus leaves drying application. In any food technology, the dryer is the key component for quality drying food and herbs etc. An oven is modified to produce high technology drying system. A mathematical model is developed based on time response characteristics of the system. A second order model is found to adequately represent the system as it gives best fit with better properties than the first order model with error between measured data and simulation data is 0.44. Validation procedures show that the derived model is indeed a good enough representation of drying system. The infrared dryer system is highly non-linear and exhibits varying model parameters. An identification system is introduced to estimate the parameters and determine mathematical model of the system. ARMAX of na = 2, nb = 1 and nc = 1 polynomial model show best fit to experimental response of PRBS input.

View
Thumbnail Image
Publication

The Effect of Parameters of Electrical Discharge Coatings on the Tool Electrode Erosion and Maximum Height Roughness on NiTi Alloy

2021-01-01 , Ahmad Fairuz Mansor , Azwan Iskandar Azmi , Zain M.Z.M. , Jamaluddin R.

This paper presents the influence of electrical discharge coatings parameters on the material loss due to the tool electrode erosion (MLTE) and the maximum height roughness, Rz on the NiTi alloy substrate. Five parameters were investigated; namely polarity, discharge duration, peak current, pulse interval and gap voltage. The experimental study was carried out using 2-level factorial design and analyzed using analysis of variance (ANOVA). The analysis results showed that the discharge duration dominates the effect on MLTE and Rz up to 39.39 and 72.41%, respectively. Then, this followed by the peak current at 15.52 and 4.63%, respectively. Furthermore, several interactions between discharge duration with other parameters were also significant on the model for both responses. Higher MLTE and Rz were recorded during high discharge duration and peak current due to the impact of increasing the discharge energy.

View
Thumbnail Image
Publication

Surface roughness analysis of NiTi alloy in electrical discharge coating process

2020-12-18 , Jamaluddin R. , Lih T.C. , Ahmad Fairuz Mansor , Azwan Iskandar Azmi , Roshaliza Hamidon

Nickel-Titanium (NiTi) alloys, most widely known as nitinol, are presently employed in many micro-engineering applications such as coronary stents of medical implants due to their unique properties (shape memory effect and superelasticity). However, non-optimized surface finishing attributed a significantly high potential of nickel exposure after a long time of application. Releasing of nickel ion to the body environment can be harmful and toxicity resulting in adverse health as well as degrading the material biocompatibility. It is widely known that controlled surface roughness play a vital role in the formation of new bone ingrowths around implant. In this study, surface modification of NiTi alloy was used through electrical discharge coating (EDC); an adaptation of electrical discharge machining. The potential of EDC in which can facilitates the production of hard coatings may exploit the phenomena for the attachment of desirable materials onto the surface of materials. Therefore, the aim of this paper is to present a robust method (two levels of full factorial design and ANOVA) to determine the desired parameters and significant factors based on the surface roughness of the machined surface. Manipulation of parameters set up such as gap voltage, discharge duration and pulse interval and the current were employed and a reverse polarity was selected for this experiment. The results demonstrated that the most significant factors influence the surface coating performances are the discharge duration, current, gap voltage as well as the interaction between gap voltage and discharge duration.

View
Thumbnail Image
Publication

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.

View