scholarly journals SHAPE FACTOR ANALYSIS OF ABRASIVE PARTICLES USED IN SLURRY ABRASION TESTING

2013 ◽  
pp. 127-131
Author(s):  
AVISHKAR RATHOD ◽  
S G SAPATE ◽  
R. K. KHATIRKAR
Keyword(s):  
Particle Size ◽  
Factor Analysis ◽  
Particle Shape ◽  
Shape Factor ◽  
Abrasive Particle ◽  
Silica Sand ◽  
Abrasive Particles ◽  
Wide Range ◽  
Sliding Distance

The engineering components are subjected to surface damage by slurry abrasion such as transportation pipes carrying ore and mineral slurries, extruders, sand pumps and agitators, Apart from stress, abrasive particle hardness, slurry concentration, particle size and shape significantly influences slurry abrasion rate. The effect of abrasive particle shape on slurry abrasion behaviour of steels and cast irons which are widely used for wear protection has not been studied. The particle shape assumes significant importance due to fracture and fragmentation of the particles during the process of abrasion. In the present work, the particle shape characterization of silica sand abrasive particles was carried by shape factor analysis using image analysis technique. An attempt was made to correlate the different measures of shape factor with particle size of abrasive particles over a wide range. The characterization of slurry abrasion tester was carried out using slurry abrasion tester with silica sand slurry. The effect of sliding distance on slurry abrasion volume of mild steel was studied. The volume loss increased linearly with sliding distance. The scanning electron microscopic observations of worn our surfaces showed micro-ploughing and cutting as mechanism of material removal.

Experimental characterization of conformal hydrodynamic nanopolishing of a machined single crystal sapphire cavity

2021 ◽  
pp. 251659842110153
Author(s):  
Prashant Kumar ◽  
Rinku Mittal ◽  
Ramesh K. Singh ◽  
Suhas S. Joshi
Keyword(s):  
Particle Size ◽  
Single Crystal ◽  
Surface Finish ◽  
Abrasive Particle ◽  
Diamond Turning ◽  
Initial Surface ◽  
Workpiece Surface ◽  
Abrasive Particles ◽  
Single Crystal Sapphire

Sapphire is an important ceramic material which finds applications in fields such as temperature sensing, optics, electronics, and ceramic bearings. Polishing of sapphire has always been a difficult task for industries and research communities. Hydrodynamic polishing (HDP) is one of the prominent methods used for polishing of hard and profiled surfaces, whereas rigid tool-based methods such as diamond turning, grinding, and honing have many limitations. The HDP process involves deterministic flow of abrasive particles in the slurry between the workpiece surface and a rotating soft tool to obtain the desired surface finish. A novel experimental setup has been fabricated to realize the conformal hydrodynamic nanopolishing on single crystal sapphire cavity. In this study, the experiments were conducted to understand the effect of abrasive particle size, basicity of slurry, and change in temperature of slurry on the polishing of machined sapphire cavity. The effect of the initial surface roughness of the machined cavity on conformal hydrodynamic nanopolishing has also been investigated. A microcrack/pit-free surface has been found after the final polishing of the sapphire cavity. An improvement of 21% is found in surface finish after the final polishing using abrasive particle size of 0.06 µm. Abrasive slurry with higher basicity (pH 13) does not improve the surface finish. By heating the abrasive slurry to a temperature of 70°C–75°C, surface finish improves by ∼26% as compared to improvement of ∼ 21% at room temperature polishing.

scholarly journals Optimization of nanostructured/nano sized rice husk ash preparation

2020 ◽  
Vol 17 (3(Suppl.)) ◽  
pp. 0953
Author(s):  
Medhat Mostafa ◽  
Hamdy Salah ◽  
Amro B. Saddek ◽  
Nabila Shehata
Keyword(s):  
Particle Size ◽  
Rice Husk ◽  
Amorphous Silica ◽  
Particle Shape ◽  
Rice Husk Ash ◽  
Loss On Ignition ◽  
Shape Distribution ◽  
Disk Mill ◽  
Grinding Time

The objective of the study is developing a procedure for production and characterization of rice husk ash (RHA). The effects of rice husk (RH) amount, burning/cooling conditions combined with stirring on producing of RHA with amorphous silica, highest SiO2, lowest loss on ignition (LOI), uniform particle shape distribution and nano structured size have been studied. It is concluded that the best amount is 20 g RH in 125 ml evaporating dish Porcelain with burning for 2 h at temperature 700 °C combined with cooling three times during burning to produce RHA with amorphous silica, SiO2 90.78% and LOI 1.73%. On the other hand, cooling and stirring times affect the variation of nano structured size and particle shape distribution. However, no crystalline phases were found in RHA in all cases. Results proved that the Attritor ball mill was more suitable than vibration disk mill for pulverizing nano structured RHA with 50% of particle size (D50) lower than 45 mm and 99 % of particle size (D99) lower than 144 mm to nanosized RHA with D50 lower than 36 nm and D99 lower than 57 nm by grinding time 8.16 min to every 1 g RHA without changes in morphousity of silica.

Wear of Abrasive Particles in Slurry During Lapping

2014 ◽  
Author(s):  
James T. Lehner ◽  
Christopher A. Brown
Keyword(s):  
Particle Size ◽  
Stainless Steel ◽  
Design Of Experiments ◽  
Abrasive Particle ◽  
Steel Ball ◽  
Abrasive Particles ◽  
Individual Variable ◽  
Stainless Steel Ball ◽  
Experimental Runs

Changes in abrasive particle size, shape, and sharpness are studied in multi-axis lapping of sealing regions of stainless steel ball valves. Twelve experimental runs, investigating changes in the abrasive particle as a function of lapping load and motion, are performed during lapping. The influence of changes in the lapping load and motion are investigated using design of experiments. Changes in the size, shape, and sharpness of the abrasive particle are influenced by the load and by the motion of the seats and balls of the valves. Combinations of lapping load and motions, as opposed to any individual variable, tend to dominate the influence on the changes in the abrasive particle.

Synthesis and characterization of TiO2 nanocrystalline powder prepared by homogeneous precipitation using urea

2003 ◽  
Vol 18 (3) ◽  
pp. 571-577 ◽  
Author(s):  
Dong Seok Seo ◽  
Hwan Kim ◽  
Hang Chul Jung ◽  
Jong Kook Lee
Keyword(s):  
Particle Size ◽  
Particle Shape ◽  
Elevated Temperatures ◽  
Treatment Temperature ◽  
Precipitation Method ◽  
Nanocrystalline Powder ◽  
Homogeneous Precipitation ◽  
Homogeneous Precipitation Method ◽  
Good Crystallinity

TiO2 nanocrystalline powder was synthesized by homogeneous precipitation method using urea, and its characteristics were investigated through comparison with the powder prepared by conventional precipitation using ammonia. The homogeneously precipitated powder was anatase-type TiO2 with a particle size of 4–5 nm and a uniform spherical particle shape. The fact that the transformation from anatase to rutile was prohibited at elevated temperatures in the homogeneously precipitated powder can be useful to prepare anatase-type TiO2 thin films by calcination at high temperatures. With increasing heat-treatment temperature, the particle size of the homogeneously precipitated powder was smaller than that of the conventionally precipitated powder, and the particle shape was more uniform. The homogeneously precipitated powder showed good photocatalytic activity for Ag ion photoadsorption because the powder had both good crystallinity and a large specific surface area of 280 m2/g.

Influence of Fiber Reinforcement and Abrasive Particle Size on Three-Body Abrasive Wear of Hybrid Friction Composites

2015 ◽  
Vol 766-767 ◽  
pp. 156-161
Author(s):  
S. Manoharan ◽  
G. Ramadoss ◽  
B. Suresha ◽  
R. Vijay
Keyword(s):  
Particle Size ◽  
Abrasive Wear ◽  
Phenol Formaldehyde ◽  
Abrasive Particle ◽  
Constant Load ◽  
Silica Sand ◽  
Wear Volume ◽  
Compression Moulding ◽  
Wear Performance ◽  
Three Body

In the present study, enhancement of abrasion resistance of phenol formaldehyde (PF) resin based hybrid friction composites with different ingredients viz. binder, micron sized fibers and fillers have been synergistically investigated. Hybrid friction composites based on basalt and recycled aramid fibers were prepared using compression moulding. Three-body abrasive wear tests were conducted according to ASTM G-65 standard by dry sand/rubber wheel abrasion tester using two different size of angular silica sand abrasives (212 and 425 μm) at a constant load of 40 N. The results indicated that the wear volume loss increases with increasing abrading distance and abrasive particle size. However, the specific wear rate decreased with increasing abrading distance and increases with increase in abrasive particle size. Addition of fiber content has a significant influence on the abrasive wear performance of these composites. Further, the worn surfaces were examined by scanning electron microscopy to identify the involved wear mechanisms.

scholarly journals EFFECT OF EXPERIMENTAL VARIABLES ON TRIBOLOGICAL PROPERTIES OF MARTENSITIC STAINLESS STEEL

2013 ◽  
pp. 24-29
Author(s):  
S.G. SAPATE ◽  
AVISHKAR RATHOD ◽  
S. AHMED
Keyword(s):  
Stainless Steel ◽  
Martensitic Stainless Steel ◽  
Normal Load ◽  
Silica Sand ◽  
Processing Plant ◽  
Abrasive Medium ◽  
Slurry Concentration ◽  
Morphological Studies ◽  
Wide Range ◽  
Sliding Distance

Wear by slurry abrasion occurs during transport of abrasive slurries encountered in industrial and specially mining applications, extruders, and in slurry pumps. Steel piping systems are widely used in mining to convey the mineral, ore and tailing slurries to the processing plant, as well as to recycle the debris medium back to the mining area. Hardfacing by welding is one of the economic methods to improve wear resistance of engineering components. The present work reports slurry abrasion behaviour of hardfaced martensitic stainless steel under a wide range of experimental condition. The slurry abrasion experiments were performed using slurry abrasion test apparatus using silica sand as the abrasive medium. The effect of test parameter such as sliding distance, normal load and slurry concentration of abrasive medium on slurry abrasion behaviors of martensitic stainless steel was investigated. The slurry abrasion volume loss exhibited increasing trend with increasing sliding distance, normal load and slurry concentration, although the magnitude of increase was different in each case. The results of the investigation suggest and slurry concentration had relatively stronger effect as compared to that of normal load.. The morphological studies of the worn surfaces revealed characteristic differences in the wear pattern under different test conditions.

Advances in the Characterization of Particle Size Distributions of Abrasive Particles used in CMP

2007 ◽  
Vol 991 ◽  
Author(s):  
Mungai Kamiti ◽  
Stacey Popadowski ◽  
Edward E. Remsen
Keyword(s):  
Particle Size ◽  
Colloidal Silica ◽  
Particle Diameter ◽  
Water Soluble ◽  
Size Distributions ◽  
Organic Additives ◽  
Particle Size Distributions ◽  
Abrasive Particles ◽  
Theoretical Simulations

ABSTRACTThe use of density gradient stabilized centrifugal sedimentation (disc centrifugation) for the characterization of abrasive particles in CMP slurries is reported. For slurries prepared with ceria and colloidal silica abrasives, the technique is demonstrated as capable of providing highly repeatable analyses of the abrasive's apparent particle size distribution (PSD). The addition of water soluble organic additives to the slurries is shown to produce large shifts in the apparent PSD relative to the PSD of the pure abrasive particles. Particle-additive interactions driving the shift in apparent PSD could not be interpreted with confidence due to the lack of accurate densities for particle-abrasive complexes formed in the slurry. To address this problem, sucrose density gradients prepared using H2O and D2O were tested as spin fluids of different densities to analyze a colloidal silica standard with a narrow PSD. Preliminary results comparing experimental disc centrifuge data with theoretical simulations of the disc sedimentation pattern suggest that this technique can potentially characterize both the particle diameter and density of abrasive particles in a CMP slurry.

Particle Shape and Size Effects on Slurry Erosion of AISI 5117 Steels

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
M. A. Al-Bukhaiti ◽  
A. Abouel-Kasem ◽  
K. M. Emara ◽  
S. M. Ahmed
Keyword(s):  
Silicon Carbide ◽  
Particle Size ◽  
Aspect Ratio ◽  
Size Effects ◽  
Particle Shape ◽  
Impact Angle ◽  
Carbon Steels ◽  
Silica Sand ◽  
Slurry Erosion ◽  
Shape And 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 silicon carbide with increasing size. The erosion rate increased with the increase of particle size for the two types of erodent particles and its value was greater in the case of silicon carbide particles. At the same test conditions, it has been noticed that the particle size plays the major role in the slurry erosion of 5117 steels in comparison with the aspect ratio and circularity factor. Microcutting and plowing with serrated wear tracks were observed for coarse SiC particles having irregular and angular shape. But, for coarse SiO2 particles which had a rounded shape, the main mechanism was plowing with plain and smooth wear tracks for an impact angle of 30 deg. Indentations and material extrusion prevailed for the coarse size of the two erodents for an impact angle of 90 deg.

Scaling Laws of Wear by Slurry Abrasion of Mild Steel

2013 ◽  
Vol 446-447 ◽  
pp. 126-130
Author(s):  
Avishkar Rathod ◽  
Sanjay G. Sapate ◽  
Rajesh K. Khatirkar
Keyword(s):  
Mild Steel ◽  
Abrasive Wear ◽  
Scaling Laws ◽  
Silica Sand ◽  
Wear Behaviour ◽  
Early Failure ◽  
Abrasive Particles ◽  
Slurry Concentration ◽  
Abrasive Wear Behaviour ◽  
Sliding Distance

Wear by slurry abrasion is very expansive problem that must be taken into consideration while selecting the material for the transportation of slurry through pipeline. Abrasive wear generally occurs when abrasive slurries come in contact with the industrial engineering components or slurry transporting pipes. The abrasive particles carried by slurries eventually remove the material from the encountering surfaces which results in the early failure of the component in service. In present investigation an attempt is made to study the effect of load, slurry concentration, sliding distance on the abrasive wear behaviour of mild steel. The slurry abrasion experiments were carried out using slurry abrasion test apparatus with silica sand slurry. The findings of the present investigation indicate that slurry abrasion volume increased with slurry concentration, load and sliding distance, although the magnitude of increase was different in each case. The SEM observation of worn out surfaces revealed micro ploughing and micro cutting as wear mechanisms.

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