Ali A. Rajhi

Dr. Ali A. Rajhi

King Khalid University, Abhā, ‘Asīr, Saudi Arabia
orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 February 2023 in Crystals
Verified
Journal Article
Open access
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Karthik KrishnasamyKarthik Krishnasamy
Karthik Krishnasamy
Rajamani DevarajRajamani Devaraj
Rajamani Devaraj
Elumalai PVElumalai PV
Elumalai PV
MSMOHAMED IQBAL SHAJAHAN
MOHAMED IQBAL SHAJAHAN
ARAli A. Rajhi
Ali A. Rajhi
B. SalehB. Saleh
B. Saleh
In recent years, many researchers have focused on the preparation of carbon and basalt fiber-reinforced composites. As a result, the composites have gained popularity as an alternative to traditional materials such as wood, steel, and aluminum. Carbon and basalt fibers were used in a bidirectional woven mat, with particulates varying from 0 to 15 wt% nanoparticle SiC. The hybrid laminates were fabricated through vacuum bag infusion methods. The novelty of the research work lies in studying the influence of nanoparticle SiC-combined carbon and basalt fibers arranged in six stacking sequences, with LY556 used as polyester matrix. Specimens were prepared and tested as per ASTM standards. Tensile, flexural, impact, and hardness tests were performed on the obtained specimens and average values were obtained. It was found that 15% SiC filler addition enhanced (20%) the mechanical properties. Scanning electron microscope photos revealed the bonding between the fiber mat and the matrix of thecrystal structure. The obtained tensile strength was 346 MPa and the flexural strength was 388 MPa. Dynamic mechanical analysis showed that mechanical properties were improved with the addition of 15% SiCnanoparticles. Hence, this method can be used to manufacture structural applications and automotive parts.

28 August 2021 in Polymers
Verified
Journal Article
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KRKeshavamurthy Ramaiah
Keshavamurthy Ramaiah
VTVijay Tambrallimath
Vijay Tambrallimath
ARAli A. Rajhi
Ali A. Rajhi
SMShabbir Ahmed R. M
Shabbir Ahmed R. M
APARUN PATIL
ARUN PATIL
RMR. Makannavar
R. Makannavar
In this study, acrylonitrile butadiene styrene (ABS) and graphite powder—a solid lubricant—were filled and characterized for friction and wear responses. The fused deposition modeling (FDM) technique was utilized to synthesize ABS–graphite composites. A twin-screw extrusion approach was employed to create the composite filament of graphite–ABS that is suitable for the FDM process. Three graphite particle ratios ranging from 0% to 5% were explored in the ABS matrix. The wear and friction properties of ABS composites were examined using a pin on disc tribometer at varied sliding velocities and weights. As a result of the graphite addition in the ABS matrix, weight losses for FDM components as well as a decreased coefficient of friction were demonstrated. Furthermore, as the graphite weight percentage in the ABS matrix grows the value of friction and wear loss decreases. The wear mechanisms in graphite filled ABS composites and ABS were extensively examined using scanning electron microscopy and confocal microscopy.

16 March 2022 in Polymers
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Journal Article
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MRMohan Kumar H R
Mohan Kumar H R
MBMaha Gundappa M. Benal
Maha Gundappa M. Benal
PSPradeep Kumar G S
Pradeep Kumar G S
VTVijay Tambrallimath
Vijay Tambrallimath
GHGeetha H.R.
Geetha H.R.
MBMaughal Ahmed Ali Baig
Maughal Ahmed Ali Baig
One of the most promising and widely used additive manufacturing technologies, fused deposition modelling (FDM), is based on material extrusion and is most commonly used for producing thermoplastic parts for functional applications with the objectives of low cost, minimal waste and ease of material conversion. Considering that pure thermoplastic materials have a significantly poor mechanical performance, it is necessary to enhance the mechanical properties of thermoplastic parts generated using FDM technology. One of the conceivable techniques is to incorporate reinforcing materials such as short glass fibre (SGF) into the thermoplastic matrix in order to produce a polymer composite that can be used in engineering applications, such as structural applications. The morphological and mechanical properties of SGF (short glass fibre) reinforced ABS- (Acrylonitrile Butadiene Styrene) based polymer composites created via the method of FDM (fused deposition modelling) were investigated in this work. Properties were evaluated at three different weight percentages (0, 15 and 30 wt%). The composite filaments were developed using the process of twin screw extrusion. The comparison was made between ABS + SGF (short glass fibre) composites and pure ABS of mechanical properties that include surface roughness, tensile strength and low-velocity impact. The tests were carried out to analyze the properties as per ASTM standards. It has been found that the impact strength and tensile strength show an improvement in glass fibre inclusion; moreover, alongside the direction of build, the surface roughness had been reduced. The studies also focused on studying the dispersion characters of SGF in ABS matrix and its impact on the properties. Strength and modulus of SGF reinforced ABS composite has been significantly improved along with reduction of ductility. A 57% increase in tensile strength has been noted for 30 wt% addition of SGF to ABS in comparison to pure ABS. It was also interesting to note the reduction in surface roughness with every incremental addition of SGF to ABS. A 40% reduction in surface roughness has been observed with a 30 wt% addition of SGF to ABS in comparison to pure ABS.

16 January 2023 in Polymers
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Journal Article
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KGKibrom Gebru
Kibrom Gebru
GTGanesh Thothadri
Ganesh Thothadri
HTHabtamu Beri Tufa
Habtamu Beri Tufa
ARAli A. Rajhi
Ali A. Rajhi
GAGULAM MOHAMMED SAYEED AHMED
GULAM MOHAMMED SAYEED AHMED
Flax is a commercial crop grown in many parts of the world both for its seeds and for its fibers. The seed-based flax variety (linseed) is considered less for its fiber after the seed is extracted. In this study, linseed straw was utilized and processed to extract fiber and cellulose through optimization of retting time and a multi-step alkaline peroxide extraction process using the Taguchi design of experiment (DOE). Effects of retting duration on fiber properties as well as effects of solvent concentration, reaction temperature, and time on removal of non-cellulosic fiber components were studied using the gravimetric technique, Fourier transform infrared (FTIR) spectroscopy and thermal studies. Based on these findings, retting for 216 h at room temperature should offer adequate retting efficiency and fiber characteristics; 70% cellulose yield was extracted successfully from linseed straw fiber using 75% ethanol–toluene at 98 °C for 4 h, 6% NaOH at 75 °C for 30 min, and 6% H2O2 at 90 °C for 120 min.

10 January 2022 in Renewable Energy
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Journal Article
Closed access
ZZZongming Zhou
Zongming Zhou
YCYan Cao
Yan Cao
AAAli E. Anqi
Ali E. Anqi
MZMohammad Zoghi
Mohammad Zoghi
HHHamed Habibi
Hamed Habibi
SASagr Alamri
Sagr Alamri

11 November 2022 in Polymers
Verified
Journal Article
Open access
PDF file
ARAli A. Rajhi
Ali A. Rajhi
Fiber-reinforced polymer (FRP) composite materials are very versatile in use because of their high specific stiffness and high specific strength characteristics. The main limitation of this material is its brittle nature (mainly due to the low stiffness and low fracture toughness of resin) that leads to reduced properties that are matrix dominated, including impact strength, compressive strength, in-plane shear, fracture toughness, and interlaminar strength. One method of overcoming these limitations is using nanoparticles as fillers in an FRP composite. Thereby, this present paper is focused on studying the effect of nanofillers added to glass/epoxy composite materials on mechanical behavior. Multiwall carbon nanotubes (MWCNTs), nano-silica (NS), and nano-iron oxide (NFe) are the nanofillers selected, as they can react with the resin system in the present-case epoxy to contribute a significant improvement to the polymer cross-linking web. Glass/epoxy composites are made with four layers of unidirectional E-glass fiber modified by nanoparticles with four different weight percentages (0.1%, 0.2%, 0.5%, and 1.0%). For reference, a sample without nanoparticles was made. The mechanical characterizations of these samples were completed under tensile, compressive, flexural, and impact loading. To understand the failure mechanism, an SEM analysis was also completed on the fractured surface.