scholarly journals Effect of impact angle and impact velocity on the slurry erosion behavior of high density polyethylene (HDPE)

2021 ◽  
Vol 171 (0) ◽  
pp. 269-281
Author(s):  
Ahmed Mostafa ◽  
Tarek Mohamed Abd El-badia ◽  
Raafat Mahmoud Gad EL- Rab
Keyword(s):  
Impact Velocity ◽  
High Density Polyethylene ◽  
Impact Angle ◽  
High Density ◽  
Slurry Erosion ◽  
Erosion Behavior

A Study on Slurry Erosion Behavior of High Chromium White Cast Iron

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
M. A. Al-Bukhaiti ◽  
A. Abouel-Kasem ◽  
K. M. Emara ◽  
S. M. Ahmed
Keyword(s):  
Impact Velocity ◽  
Erosion Resistance ◽  
Normal Incidence ◽  
Impact Angle ◽  
Silica Sand ◽  
Slurry Erosion ◽  
High Chromium ◽  
Nominal Size ◽  
Plastic Indentation ◽  
Erosion Mechanisms

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 sand which has a nominal size range of 500–710 μm was used as an erodent. The results were obtained for angles of 30 deg, 45 deg, 60 deg, and 90 deg to the exposed surface and velocities of 5, 10, and 15 m/s. The highest erosion resistance of HCCI was at normal impact and the lowest at an angle of 30 deg, irrespective of velocity. The low erosion resistance at an oblique angle is due to large material removal by microcutting from ductile matrix and gross removal of carbides. The effect of velocity, over the studied range from 5 m/s to 15 m/s, on the increase in the erosion rate was minor. The change of impact velocity resulted in changing the slurry erosion mechanisms. At normal incidence, plastic indentation with extruded material of the ductile matrix was the dominant erosion mechanism at low impact velocity (5 m/s). With increasing impact velocity, the material was removed by the indentation of the ductile matrix and to smaller extent of carbide fracture. However, at high impact velocity (15 m/s), gross fracture and cracking of the carbides besides plastic indentation of the ductile matrix were the dominant erosion mechanisms.

Effect of Impact Angle on Slurry Erosion Behavior and Mechanisms of Carburized AISI 5117 Steel

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Y. M. Abd-Elrhman ◽  
A. Abouel-Kasem ◽  
K. M. Emara ◽  
S. M. Ahmed
Keyword(s):  
Erosion Resistance ◽  
Impact Angle ◽  
Silica Sand ◽  
Ductile Material ◽  
Hardness Profile ◽  
Slurry Erosion ◽  
Erosion Behavior ◽  
Nominal Size ◽  
Impact Angles ◽  
The Impact

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 electron microscope (SEM) images at different locations on eroded surface using stepwise erosion combined with relocation SEM were presented. The study is also focused on studying the erosion wear resistance properties of AISI 5117 steel after carburizing at different impact angles. The tests were carried out with particle concentration of 1 wt. %, and the impact velocity of slurry stream was 15 m/s. Silica sand has a nominal size range of 250 – 355 μm was used as an erodent. The results showed that, carburizing process of steel increased the erosion resistance and hardness compared with untreated material for all impact angles. The erosion resistance of AISI 5117 steel increases by 75%, 61%, 33%, 10% at an impact angle of 30 deg, 45 deg, 60 deg, and 90 deg, respectively, as result of carburizing, i.e., the effectiveness of carburizing was the highest at low impact angles. Treated and untreated specimens behaved as ductile material, and the maximum mass loss appeared at impact angle of 45 deg. Plough grooves and cutting lips appeared for acute impact angle, but the material extrusions were for normal impact angles. The erosion traces were wider and deeper for untreated specimens comparing by the shallower and superficial ones for the carburized specimens. Chipping of the former impact sites by subsequent impact particles plays an important role in developing erosion.

Composition and Surface Topography Effects on Apatite-Forming Ability of Ceramic-Polymer Composites

2003 ◽  
Vol 774 ◽  
Author(s):  
Susan M. Rea ◽  
Serena M. Best ◽  
William Bonfield
Keyword(s):  
Surface Topography ◽  
High Density Polyethylene ◽  
High Density ◽  
Apatite Layer ◽  
Biologically Active ◽  
Human Blood Plasma ◽  
Apatite Formation ◽  
Polyethylene Matrix ◽  
Composite Surface ◽  
X Ray

AbstractHAPEXTM (40 vol% hydroxyapatite in a high-density polyethylene matrix) and AWPEX (40 vol% apatite-wollastonite glass ceramic in a high density polyethylene matrix) are composites designed to provide bioactivity and to match the mechanical properties of human cortical bone. HAPEXTM has had clinical success in middle ear and orbital implants, and there is great potential for further orthopaedic applications of these materials. However, more detailed in vitro investigations must be performed to better understand the biological interactions of the composites and so the bioactivity of each material was assessed in this study. Specifically, the effects of controlled surface topography and ceramic filler composition on apatite layer formation in acellular simulated body fluid (SBF) with ion concentration similar to those of human blood plasma were examined. Samples were prepared as 1 cm × 1 cm × 1 mm tiles with polished, roughened, or parallel-grooved surface finishes, and were incubated in 20 ml of SBF at 36.5 °C for 1, 3, 7, or 14 days. The formation of a biologically active apatite layer on the composite surface after immersion was demonstrated by thin-film x-ray diffraction (TF-XRD), environmental scanning electron microscopy (ESEM) imaging and energy dispersive x-ray (EDX) analysis. Variations in sample weight and solution pH over the period of incubation were also recorded. Significant differences were found between the two materials tested, with greater bioactivity in AWPEX than HAPEXTM overall. Results also indicate that within each material the surface topography is highly important, with rougher samples correlated to earlier apatite formation.

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