S. M. Ahmed

Majmaah University · Department of Mechanical Engineering

This paper presents the design and development of a control scheme, for a robot master–slave teleoperation system man–machine interface. The developed system consists of JUPITER XL SCARA robot as a slave manipulator with only the first two links activated, a wireless User Datagram Protocol (UDP) network, and PC as a master controller. The system mo...

In this research, we utilize image processing to analyze surfaces acquired from slurry-erosion tests carried out on AISI 5177 steel at various velocities and impact angles of 30o and 90o. The fractal and wavelet decomposition transform are two analysis tools that are particularly promising in this regard. These can be used to extract metrics that c...

Stepwise cavitation erosion is used to study pits formed by microjets. The aim is to determine the role of the pit in the development of cavitation erosion damage, including geometrical features of the pitted area and pit counting. The study also identified the dominant feature in the development of cavitation damage. We used a vibratory cavitation...

In this paper, the mechanism of energy transfer from cavitation bubbles to solids is demonstrated as shock waves. To identify this mechanism, cavitation bubble structures, the corresponding damaged surface, and the wear particles in vibratory erosion tests on pure aluminum Al-99.999 using high-speed and SEM photography were observed. The eroded sur...

Multi-drug resistant Typhoid fever (resistant to previously used chloramphenicol, ampicillin, amoxicillin, and trimethoprim-sulfamethoxazole) has been commonly described in the South East Asia region and a recent report suggests that the salmonella typhi have reduced response to fluoroquinolones (nalidixic acid-resistant). The optimum treatment pro...

Solid particle shape and size effects on the slurry erosion behavior of AISI 5117 carbon steels are investigated, using whirling-arm ring for two different erodent particles, namely, silica sand (SiO 2) and silicon carbide (SiC). From this work, it was found that aspect ratio and circularity factor (CF) increase for silica sand and decrease for sil...

Purpose This paper aims to clarify the relationship between the slurry erosion and one of the case hardening treatments, i.e. boronizing in this study, for AISI-5117 steel alloy. AISI-5117 steel alloy was used because of its variety applications in the field of submarine equipment. Most of the slurry erosion factors such as velocity, impact angle...

Purpose This paper is to investigate the influence of slurry concentration on the erosion behavior of AISI 5117 steel and High-Cr white cast iron (HCCI) using a whirling-arm rig. In this study, the slurry erosion mechanism with particle concentration has been studied. Design/methodology/approach The tests were carried out with particle concentra...

Purpose Removed particles from stationary specimen-aluminum (Al-99.92) produced by vibratory cavitation erosion tests in distilled water and glycerol-water mixtures were analyzed. Design/methodology/approach The particle morphology which include particle surface topography, size distribution, particle size parameters and particle shape parameter...

High chromium white irons (HCCIs) are used extensively throughout the mineral processing industry to handle erosive and corrosive slurries. This study is an investigation of the effect of impact angle and velocity on slurry erosion of HCCI. The tests were carried out using a rotating whirling-arm rig with particle concentration of 1 wt. %. Silica s...

In the present work, the image features of cavitation erosion surfaces at different temperatures are extracted using wavelet decomposition transform. The results obtained indicate that the extract parameters, wavelet energy, and entropy can characterize the cavitation intensity in a similar manner to that of the mass loss and average particle size...

Solid particle shape and size effects on the slurry erosion behavior of AISI 5117 carbon steels are investigated, using whirling-arm ring for two different erodent particles, namely, silica sand (SiO2) and silicon carbide (SiC). From this work, it was found that aspect ratio and circularity factor (CF) increase for silica sand and decrease for sili...

In the present work, electroless Ni-Co-P and Co-P coatings were produced on AISI 1045 steel with and without post-heat treatment. The properties of electroless coatings were characterized using an optical microscope, and microhardness tester. The cavitation erosion resistance of coatings was evaluated using a vibratory cavitation test. The test was...

The erosion-corrosion (E-C) wear behaviors of electroless nickel phosphorus (Ni-P) coating, carburizing and untreated low alloy steel AISI 5117 in water-sand slurry and saline-sand slurry were investigated using whirling-arm tester. The E-C wear mass loss was measured to evaluate the effect of mediums and surface modifications. The microstructure o...

In the present work, electroless Ni-Co-P and Co-P coatings were produced on AISI 1045 steel with and without post-heat treatment. The properties of electroless coatings were characterized using an optical microscope, and microhardness tester. The cavitation erosion resistance of coatings was evaluated using a vibratory cavitation test. The test was...

In the present work, stepwise erosion technique was carried out to investigate in detail the influence of impact angle on the erosion process of AISI 5117 steel. The number of impact sites and their morphologies at different impact angles were investigated using scanning electron microscope (SEM) examination and image analysis. The tests were carri...

The paper reports the influence of carburizing on the slurry erosion behavior of AISI 5117 steel using a whirling-arm rig. The microstructure and hardness profile of the surface layer of carburized steel were investigated. For characterizing the slurry damage process and for better understanding of material removal at different angles, scanning ele...

Electroless Nickel-Phosphorus coatings have had a lot of interest in various industries due to outstanding characteristics. Some of the highlighted characteristics of electroless NiP coatings are superior corrosion and wear resistance. But the effectiveness of electroless NiP coating in resisting cavitation damage is not studied so well and is not...

The erosion–corrosion of carburized and untreated low alloy steel (AISI 5117) has been investigated using slurry whirling-arm test rig. Erosion–corrosion tests were carried out in slurries composed of sand particles and either tap water or 3 % NaCl solution. The tests were carried out with particles concentration of 1 wt% and slurry stream impact v...

Field tests are specifically designed to monitor the deterioration behaviour of the Soderberg pipeline, to evaluate alternative materials of construction, to determine the effect of process conditions, and determining the most useful means for reducing the deteriorating rate. It was found that the change in steel composition affects both erosion an...

This paper deals with the analysis of eroded surfaces obtained from cavitation-erosion experiments on stainless steel in water and oil-in-water (o/w) emulsions using image processing. Two analysis techniques that are very promising in this respect are the wavelet decomposition transform and fractals. These can be used to extract parameters that cha...

Wear particles produced by vibratory cavitation erosion tests on 1045 carbon steels in three different corrosive media: distilled water, tap water and 3 % NaCl water were analyzed. Scanning electron microscope (SEM) of wear particles were acquired, forming database for further analysis. This study shows that there is no remarkable difference in the...

The cavitation bubble structures for the stationary specimen method were clarified for various distances, h, between the stationary specimen and the horn-tip surface. The generated cavitation bubbles constituted a huge number of tiny bubbles and bubble clusters of different sizes. The maximum cluster size was 1.4 mm. The observed cavitation pattern...

Cavitation erosion resistance of steels is important in many applications. The investigation of such resistance, under different conditions, should be very useful. Cavitation erosion tests were carried out on carbon steel AISI-1045 using an ultrasonic induced cavitation facility. Cavitation erosion pits and their effect on the localized corrosion w...

In the present work, the topographical images of cavitation erosion surfaces at water and oil-in-water (o/w) emulsions were quantified using fractal analysis. The oil-in-water emulsion concentrations were 2, 5 and 10 wt. %, which are in the popular range used in hydraulic systems. The study showed that the variation of fractal dimension calculated...

The ring areas formed around micropits in cavitation erosion experiments were investigated. The corrosion behavior and vibratory cavitation erosion tests of mild carbon steel in tap and distilled water were carried out. Thus, the ring areas were densely formed in tap water and scarcely formed in distilled water in cavitation tests. The ring areas f...

The effect of temperature on the wear particles produced by vibratory cavitation erosion tests on Al-99.92 in distilled water was analyzed. Scanning electron microscope images of wear particles were obtained, forming a database for further analysis. This study showed that the variation of average particle size with temperature was very much similar...

Design and Performance of Slurry Erosion Tester A slurry whirling arm erosion test ring was constructed and a series of erosion tests and post-erosion analysis were carried out using a paint erosion indication technique. The pattern of the paint removal presented a highly visual and accelerated map for the erosion process and its behavior. Also, th...

In the present work, the topographical images of slurry erosion surfaces at different impact angles were quantified using fractal analysis. The study showed that the variation of fractal value of slope of linearized power spectral density with the impact angle is largely similar to the relationship between the erosion rate and the impact angle. Bot...

Cavitation erosion pits and their effects on erosion progression were investigated in detail for SUS 304 stainless steel, alpha + beta brass (60/40), and pure aluminum (Al-99.999 and Al-99.92) by means of vibratory erosion. Two kinds of erosion pits were found on the specimen surfaces, one by microjet impact and the other by shockwave blow. Systema...

Wear particles produced by vibratory cavitation erosion on stationary-aluminum Al-99.999 were analyzed using scanning electron microscope (SEM), forming a database for further analysis. The particle morphology features were first clarified based on the characteristic stages of the vibratory erosion rate-time pattern. Next, size, area, perimeter and...

Wear particles produced by vibratory cavitation erosion tests on 1017 carbon steels in water and oil-in-water (o/w) emulsions were analyzed. Scanning electron microscope (SEM) images of wear particles were acquired, forming a database for further analysis. The particle morphology features were first clarified. Next, the size parameters (size, area,...

The mechanism of cavitation erosion is investigated in detail through observations of the removed particles from pure aluminum (Al-99.999). The particles removed during the incubation stage have distinctive characteristics compared to those removed in the subsequent stages. These characteristics are distinguished by lamellae structure, foldness, wa...

In the present work a series of systematic erosion tests were carried out to investigate the influence of impingement angle on erosion mechanisms of 1017 steel and high-Cr white cast iron using a slurry whirling-arm test rig. Scanning electron microscopy (SEM), image analysis system, optical microscopy as well as gravimetric and microhardness measu...

The effects of temperature on the impact pressure, the erosion of pure aluminum (Al-99.999) and the cavitation aspects developed by vibratory cavitation erosion are investigated. It was found that the impact pressure strongly depends on temperature, as well as on the radial distance. The pressure is higher for lower temperature especially in the ce...

The mechanism of cavitation erosion is investigated in detail for SUS 304 stainless steel, a typical erosion-resistant material. Systematic observations of eroded surfaces and dislodged particles show that the predominant failure mode in cavitation erosion is fatigue. Characteristic features of such failures include (1) packets of slip bands, (2) c...

The term "hard erosion" means erosion harder than ordinary erosion of two figures or more. We carefully observed the cavitation aspects of several types and the corresponding eroded surfaces in typically accelerating erosion tests on a typical material of 304 stainless steel by means of high-speed and SEM photography under a specified condition of...

Scanning electron microscopic investigations of particles produced by cavitation erosion and fracture surfaces for 304 stainless steel, revealed that the dominant mode of cavitation erosion is fatigue failure. In addition, the surface roughness facilitates the separation of particles, especially the longitudinal ones. The gathered particles can be...

Vibratory-erosion tests on a typical ductile material, 304 stainless steel, were carried out under a specified condition of uniform cavitation-nuclei-size distributions. We systematically investigated the behavior of fracture modes on a smooth surface one order of magnitude smaller in roughness than the ASTM recommended value, as well as the small...

The behaviour of the vibratory cavitation erosion on typical machinery material, SUS 304 stainless steel, is investigated using a scanning electron microscope and a profilometer. The tests are carried out under conditions of uniform cavitation nuclei size distribution. It is observed that the polishing Unes act as weak points for the formation of p...

We attempt to simulate several actual cavitating states appearing in the vibrating field through indirect vibratory erosion tests, whose vibratory system conforms to the ASTM Standards. The cavitation aspects and the distributions of cavitation-induced pressures are systematically observed for various distances L between the stationary specimen and...

In order to clarify the necessary conditions for cavitation-erosion tests with a vibratory apparatus, we carefully measure the cavitation-nuclei-size distributions and the relative air content rate of test water with respect to time by means of a Coulter counter and a van Slyke apparatus, respectively. It is found that the exponent of the distribut...

Vibratory-erosion tests on a typical ductile material, 304 stainless steel, were carried out under a specified condition of uniform cavitation-nuclei-size distribution. We systematically investigated the behavior of the fracture mode on a smooth surface one figure smaller in roughness than the ASTM recommended value, as well as small roughness effe...

Vibratory-erosion tests on a typical erosion-resistant material made of 304 stainless steel were carried out. We carefully observed the erosion patterns and the surface roughness aspects with respect to test time, under a specified condition of uniform nuclei-size distribution, by a scanning electron microscope and a profilometer. The eroded surfac...

The behavior during the initial incubation period of vibratory cavitation erosion tests of a typical machinery material of 304 stainless steel was investigated under a specified condition of uniform nuclei size distribution, using a scanning electron microscope and a profilometer. We observed two types of erosion pits and plastically developed surf...

In order to establish the necessary condition for such cavitation-erosion-tests in vibratory-erosion test-apparatus, the cavitation-nuclei size-distribution and the relative air content rate of test water were carefully measured with respect to test time, by means of a Coulter-counter and a van Slyke apparatus respectively. It is worth noticing in...

Vibratory-erosion tests on a typical erosion-resistant material made of 304 stainless steel were carried out. We carefully observed the erosion patterns and the surface roughness aspects with respect to test time, under a specified condition of uniform nuclei-size distribution, by a scanning electron microscope and a profilometer. The eroded surfac...