Papers by Abdou Abdel-samad
Thermal spray, May 10, 2004
Coatings are used for modifying the surface properties of critical components subjected to mechan... more Coatings are used for modifying the surface properties of critical components subjected to mechanisms such as corrosion, oxidation, wear, or under an excessive heat load failure. Selection of the coating material and method of depositions are very important for any application. Coatings are effectively and economically used to guard the substrate surface from wear also to reduce friction. The tribological response of a coating system depends on many factors like coating properties, counterpart, substrate, interface, and running conditions. Hence, selection of the appropriate coating for a given tribological application is difficult. Thermally sprayed WC and CrC based cermet coatings are extensively used in the hydro turbine for resistance to wear like abrasive, erosive and cavitation. The NiCrAlY coating showe d better resistance to high-temperature oxidation and corrosion due to the formation of protective oxides. At high temperature working environment and chemically aggressive condition NiCrSiBC alloy reveals a good balance between corrosion and wear resistance. The NiCrBSi coating showed a good surface finish as well as the bonding interface. This paper presented the review related to the selection of coating powder and process of protective wear resistance coating by thermal spray techniques. The effect of spraying techniques and spraying parameters on the performance of the coating is different for every coating. The wear types, powders, Plasma spray and HVOF spray methods are discussed to identify the coating for a specific application.
Applied Sciences
In the aircraft industry, the high-strength aluminum alloys AA7075 and AA2024 are extensively use... more In the aircraft industry, the high-strength aluminum alloys AA7075 and AA2024 are extensively used for the manufacture of structural parts like stringers and skins, respectively. Additive manufacturing (AM) of the AA7075-T6 aluminum alloy via friction stir deposition to build continuously multilayered parts on a substrate of AA2024-T4 aluminum has not been attempted so far. Accordingly, the present work aimed to explore the applicability of building multilayers of AA7075-T6 alloy on a substrate sheet of AA2024-T4 alloy via the additive friction stir deposition (AFSD) technique and to optimize the deposition process parameters. The experiments were conducted over a wide range of feed rates (1–5 mm/min) and rotation speeds (200–1000 rpm). The axial deposition force and the thermal cycle were recorded. The heat input to achieve the AFSD was calculated. The AA7075 AFSD products were evaluated visually on the macroscale. The microstructures were also investigated utilizing an optical mic...
Thermal Spray 2004: Proceedings from the International Thermal Spray Conference
Die-casting moulds are subjected to severe conditions of cyclical thermal and mechanical loads, a... more Die-casting moulds are subjected to severe conditions of cyclical thermal and mechanical loads, as well as chemical and mechanical wear. Dies mostly fail due to a combination of wear mechanisms. Heat checking, erosion, melt corrosion and soldering often lead to complete die failure. Ceramic plasma-sprayed coatings have a great potential for die protection, since they are chemically inert, and show high form stability at elevated temperatures. Furthermore, they show good resistance against thermal shock due to the porous state of the coated layer and low Young’s modulus. In the present study, the influence of hot isostatic pressing on thermal fatigue resistance of plasma spraying coatings is investigated. Thermal and thermomechanical tests were applied to characterise their ability to protect dies. The coatings were evaluated by residual stress measurements, metallography, hardness test and X-ray diffraction.
SSRN Electronic Journal, 2018
Coatings are used for modifying the surface properties of critical components subjected to mechan... more Coatings are used for modifying the surface properties of critical components subjected to mechanisms such as corrosion, oxidation, wear, or under an excessive heat load failure. Selection of the coating material and method of depositions are very important for any application. Coatings are effectively and economically used to guard the substrate surface from wear also to reduce friction. The tribological response of a coating system depends on many factors like coating properties, counterpart, substrate, interface, and running conditions. Hence, selection of the appropriate coating for a given tribological application is difficult. Thermally sprayed WC and CrC based cermet coatings are extensively used in the hydro turbine for resistance to wear like abrasive, erosive and cavitation. The NiCrAlY coating showe d better resistance to high-temperature oxidation and corrosion due to the formation of protective oxides. At high temperature working environment and chemically aggressive condition NiCrSiBC alloy reveals a good balance between corrosion and wear resistance. The NiCrBSi coating showed a good surface finish as well as the bonding interface. This paper presented the review related to the selection of coating powder and process of protective wear resistance coating by thermal spray techniques. The effect of spraying techniques and spraying parameters on the performance of the coating is different for every coating. The wear types, powders, Plasma spray and HVOF spray methods are discussed to identify the coating for a specific application.
Journal of Materials Science, 2000
Aluminium oxide is relatively cheap material, abundant almosteverywhere and therefore it is widel... more Aluminium oxide is relatively cheap material, abundant almosteverywhere and therefore it is widely used for thermal sprayapplications. Various alumina based powder containing 13 wt. Titania, two different 40 wt.% Zirconia and three differentcompositions of alumina-zirconia-chromia were deposited byatmospheric plasma spraying (APS) and high power plasma spraying(HPPS). The coatings obtained were evaluated by optical microscopy,microhardness measurements, X-ray diffraction and porositymeasurements. Moreover,
Journal of Materials Processing Technology, 2005
The prosthetic composite materials have been improved and are now widely used for various kinds o... more The prosthetic composite materials have been improved and are now widely used for various kinds of prosthetic restorations. Three composite materials SR Chromasit, Palfique Estelite, and Palfique Toughwell were assessed, and SR Ivocron material was used as a reference material. The composite specimens polymerized with their proprietary curing units and were stored with the reference specimen in water for 14 days and subsequently subjected to toothbrush/dentifrice abrasion. The amounts of wear loss of each specimen after 20,000 strokes were determined. Palfique Toughwell composite material showed less wear and surface roughness than any of the other assessed materials.
Engineering Failure Analysis, 2009
... El-Sayed A. Rassoul a , E-mail The Corresponding Author , Abdou Abdel-Samad a , Corresponding... more ... El-Sayed A. Rassoul a , E-mail The Corresponding Author , Abdou Abdel-Samad a , Corresponding Author Contact Information , E-mail The Corresponding Author and Rashad El-Naqier b , E-mail The Corresponding Author. a Dept. of Prod. Engg. and Mech. ... [9] Yehia Farag. ...
Surface and Coatings Technology, 2006
Die-casting moulds are subjected to severe conditions of cyclical thermal and mechanical loads, a... more Die-casting moulds are subjected to severe conditions of cyclical thermal and mechanical loads, as well as chemical and mechanical wear. Dies mostly fail due to a combination of wear mechanisms. Heat checking, erosion, hot corrosion and soldering often lead to complete die failure. Ceramic plasma-sprayed coatings have a great potential for die protection, since they are chemically inert, and show
Quintessence International
To assess the influence of ormocer, nanofilled, nanoceramic, and microhybrid composite restorativ... more To assess the influence of ormocer, nanofilled, nanoceramic, and microhybrid composite restorative systems on the fracture resistance of maxillary premolars with Class II mesio-occlusodistal (MOD) cavities. Eighty-four sound maxillary human premolars were divided into six groups of 14 teeth each. Teeth in the first group were left intact and tested as unprepared positive controls. Teeth in the remaining five groups were prepared with MOD cavities. Teeth in one of the five groups were unrestored and tested as negative control. The remaining four groups were restored with an ormocer (Admira), a nanofilled composite (Filtek Supreme), a nanoceramic composite (CeramX mono), and a microhybrid composite (Tetric Ceram). All groups were stored in water at 37°C for 24 hours and thermocycled 500 times between 5°C and 55°C. The specimens were loaded occlusally in a universal testing machine using a metal sphere that contacted only the teeth on the cuspal inclines until fracture occurred. The re...
Solid State Phenomena, 2021
The process of fabricating reliable materials according to efficient usage has become one of the ... more The process of fabricating reliable materials according to efficient usage has become one of the most vital concerns. In this paper, the fabrication of functionally graded materials (FGMs) is the target using a specified application of an internal combustion engine piston model to achieve such a gradient. With a convenient rotational speed under the concept of centrifugal casting technique, the required gradient piston was successfully produced from two pure aluminum alloys A336 and A242 by such a new mechanical technique for having the required gradient. The percentages of internal ingredients, mainly, silicon were controlled axially through the piston. Chemical composition analysis, micro-hardness and wear resistance tests were performed to check the gradient and to know the difference between mechanical properties for each piston portion from its top combustion chamber to its skirt, achieving compatible results through performed tests. Obvious opposite direction gradient of silic...
Quintessence international, 2011
OBJECTIVE To assess the influence of ormocer, nanofilled, nanoceramic, and microhybrid composite ... more OBJECTIVE To assess the influence of ormocer, nanofilled, nanoceramic, and microhybrid composite restorative systems on the fracture resistance of maxillary premolars with Class II mesio-occlusodistal (MOD) cavities. METHOD AND MATERIALS Eighty-four sound maxillary human premolars were divided into six groups of 14 teeth each. Teeth in the first group were left intact and tested as unprepared positive controls. Teeth in the remaining five groups were prepared with MOD cavities. Teeth in one of the five groups were unrestored and tested as negative control. The remaining four groups were restored with an ormocer (Admira), a nanofilled composite (Filtek Supreme), a nanoceramic composite (CeramX mono), and a microhybrid composite (Tetric Ceram). All groups were stored in water at 37°C for 24 hours and thermocycled 500 times between 5°C and 55°C. The specimens were loaded occlusally in a universal testing machine using a metal sphere that contacted only the teeth on the cuspal inclines ...
The mechanical and corrosion performances of carbon steel arc weld joints in service environments... more The mechanical and corrosion performances of carbon steel arc weld joints in service environments have been established to be influenced by the process parameters used in carrying out the welding process. Gas Metal Arc Welding (GMAW) and Shielded Metal Arc Welding (SMAW) processes are leading in the development in arc welding process which are higher productivity, common and good in quality . PURPOSE: In this study, the effects of different parameters on welding penetration, microstructural , hardness and corrosion resistance measurement in carbon steel by using the gas metal arc welding and shielded metal arc welding are investigated . MATERIALS AND METHODS: The variables that choose in this study are weld process, arc voltage, welding current and corrosion environment .The base metal seamless pipe carbon steel grade B that having the 7.1mm thickness of base metal (ASME A106) was used and the arc voltage and welding current were chosen as range (27 – 38) V, and (50 – 100) A of (SMA...
Bulletin of the Faculty of Engineering. Mansoura University
The present work is a study of the effect of specimen shape for different specimen types and test... more The present work is a study of the effect of specimen shape for different specimen types and test duration times on the erosion process. Erosion changes the surface geometry of the parts, components of machines that will affect the performance and efficiency of the parts to be lower than design and may cause failure. Experimental test was carried out using a specially designed test-rig to investigate the effect of specimen shape for Stainless steel 304, and steel 37 coated with Ni-Cr thin film (38 m) in material erosion. The test-rig is based on Specimens rotate in slurry pot, sand in water, with a controlled speed to simulate a required relative velocity between
Journal of Al-Azhar University Engineering Sector
The present work is a study of the effect of slurry particle type, impact angle, and velocity, an... more The present work is a study of the effect of slurry particle type, impact angle, and velocity, and test duration time on the erosion process of stainless steel 316, 304. Erosion change the surface geometry of the parts, components of machines that will affect the performance and efficiency of the parts may be causing the parts failure. Mud or sand particles were used in water with concentration of 40 wt. %. The particle maximum dimension is 550 µm. Specimens velocities were 2.3m/s and 5.75 m/s using a simple test rig was designed and fabricated to investigate slurry erosion and cavitation erosion. This is done by rotating the specimens in a transparent tank containing slurry with the desired composition and concentration with a fluid. The velocity of specimens can be from zero m/s up to 14 m/s. The specimen weight loss of the eroded sample was examined and was evaluated. The weight loss is measured using a balance with sensitivity of 0.0001g, and the surface is photography using SEM examination. Results show that; the increase of particles hardness results in increase the weight loss. And increase the testing time affecting the wear rate. Also increase velocity increasing weight loss.
Chlorine levels and pH receive much attention in the swimming world as they determine whether the... more Chlorine levels and pH receive much attention in the swimming world as they determine whether the pool water will be people–friendly that are safe, comfortable and enjoyable for swimmers or causing irritation and negative effects on the body. Enamel samples were prepared for testing microhardness and surface roughness. A total of 80 specimens were prepared for this study. They were divided into four main groups according to pH of chlorinated water 7.5, 6.5, 5.5 and 4.5 as slightly alkaline, slightly acidic, medium and highly acidic, each group 20 specimens. Each group was further classified into two classes according to the frequency of immersion (Regular = 2 hours/day and intensive = 4 hours/day). Each class was divided into two equal subclasses according to the testing procedure (Microhardness or surface roughness). The subgroup placed in pH 7.5 was used as a control as recommended by many investigators. Microhardness and surface roughness of each specimen were tested before and o...
Chlorine levels and pH receive much attention in the swimming world as they determine whether the... more Chlorine levels and pH receive much attention in the swimming world as they determine whether the pool water will be people–friendly that are safe, comfortable and enjoyable for swimmers or causing irritation and negative effects on the body. Restorative material samples were prepared for testing microhardness and surface roughness. A total of 160 specimens were prepared for this study. They were divided into two main groups (Composite and compomer) each group 80 specimens. Each group was divided into four subgroups according to pH of chlorinated water (7.5, 6.5, 5.5 and 4.5) (Slightly alkaline, slightly acidic, medium and highly acidic) each group 20 specimens. Each group was further classified into two classes according to the frequency of immersion (Regular = 2 hours/day and intensive = 4 hours/day). Each class was divided according to the testing procedure (Microhardness or surface roughness) into two equal subclasses. The subgroup placed in pH 7.5 was used as a control as recom...
Quintessence international (Berlin, Germany : 1985)
To assess the influence of ormocer, nanofilled, nanoceramic, and microhybrid composite restorativ... more To assess the influence of ormocer, nanofilled, nanoceramic, and microhybrid composite restorative systems on the fracture resistance of maxillary premolars with Class II mesio-occlusodistal (MOD) cavities. Eighty-four sound maxillary human premolars were divided into six groups of 14 teeth each. Teeth in the first group were left intact and tested as unprepared positive controls. Teeth in the remaining five groups were prepared with MOD cavities. Teeth in one of the five groups were unrestored and tested as negative control. The remaining four groups were restored with an ormocer (Admira), a nanofilled composite (Filtek Supreme), a nanoceramic composite (CeramX mono), and a microhybrid composite (Tetric Ceram). All groups were stored in water at 37°C for 24 hours and thermocycled 500 times between 5°C and 55°C. The specimens were loaded occlusally in a universal testing machine using a metal sphere that contacted only the teeth on the cuspal inclines until fracture occurred. The re...
To assess the influence of ormocer, nanofilled, nanoceramic, and microhybrid composite restorativ... more To assess the influence of ormocer, nanofilled, nanoceramic, and microhybrid composite restorative systems on the fracture resistance of maxillary premolars with Class II mesio-occlusodistal (MOD) cavities. Eighty-four sound maxillary human premolars were divided into six groups of 14 teeth each. Teeth in the first group were left intact and tested as unprepared positive controls. Teeth in the remaining five groups were prepared with MOD cavities. Teeth in one of the five groups were unrestored and tested as negative control. The remaining four groups were restored with an ormocer (Admira), a nanofilled composite (Filtek Supreme), a nanoceramic composite (CeramX mono), and a microhybrid composite (Tetric Ceram). All groups were stored in water at 37°C for 24 hours and thermocycled 500 times between 5°C and 55°C. The specimens were loaded occlusally in a universal testing machine using a metal sphere that contacted only the teeth on the cuspal inclines until fracture occurred. The results were analyzed by Kruskal-Wallis and Mann-Whitney U tests. The level of significance was set at .05. The difference between the mean cuspal fracture resistance of the unprepared positive control teeth and those restored with ormocer, nanofill, and microhybrid composite was found to be statistically significant (P < .05). No statistically significant difference in cuspal fracture resistance was found between the unprepared positive control teeth and those teeth restored with nanoceramic composite (P > .05). Under compressive load testing, teeth with microhybrid, ormocer, and nanofilled composite restorations had lower cuspal fracture resistance than those with nanoceramic composite restorations.
Journal of Surface Engineered Materials and Advanced Technology, 2014
The majority of naval ships are constructed of mild steel. Corrosion is a major concern in a mari... more The majority of naval ships are constructed of mild steel. Corrosion is a major concern in a maritime environment. This particular type of material degradation has recently received more attention by the marine industry. The present work aims to investigate the effect of recent coatings used in marine ship surfaces for preventing corrosion. Experiments were performed according to standard tests to evaluate and measure the coating adhesion to steel and to measure the corrosion wear rate if any for three types of coatings. An accelerated corrosion test was conducted to duplicate in the laboratory the field corrosion performance of a product. The results indicate that all tested types of paint have resulted in a reduction in the corrosion rate compared with the uncoated steel. A minimum corrosion rate of 0.8 mm/year for the coat "Hempadur 52,140" was obtained compared to 2.1 mm/year for the uncoated steel. A microscopic examination of the corroded steel surfaces was conducted which prevailed pitting behavior with different degree. The minimum corroded surface exhibited few pitting attack in comparison to other specimens. Although the pitting attack of the surface layer (paint), one can drive a conclusion that sample surface without coating is aggressively attacked by pits.
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Papers by Abdou Abdel-samad