The effect of grain size on the slurry erosive wear of Ce-TZP ceramics

2000 ◽  
Vol 43 (5) ◽  
pp. 465-470 ◽  
Author(s):  
S Lathabai
Keyword(s):  
Grain Size ◽  
Erosive Wear

The Use of Closely Spaced Vickers Indentations to Model Erosion of Polycrystalline α-Al2O3

2004 ◽  
Vol 843 ◽  
Author(s):  
Adolfo Franco Júnior ◽  
Steve G. Roberts
Keyword(s):  
Grain Size ◽  
Impact Velocity ◽  
Erosive Wear ◽  
Significant Loss ◽  
Crack Coalescence ◽  
Good Correspondence ◽  
Mean Grain Size ◽  
Static Indentation ◽  
Α Al2o3 ◽  
Wear Maps

ABSTRACTArrays of closely spaced quasi-static indentation were made on specimens of polycrystalline α-Al2O3, mean grain size G=1.2, 3.8 and 14.1 μm. The critical indentation spacing to produce crack coalescence between indentations, and thus significant loss of material from the surface, was determined. These data are compared to results for low-impact-velocity wet erosive wear on the same materials; a good correspondence is found. The indentation data can be used to produce “wear maps”, which provide a guideline for predicting the low-impact-velocity erosive wear resistance of brittle materials.

Effect of Erosive Particle Velocity on the Intensity of Polymeric Coating Wear

2010 ◽  
Vol 165 ◽  
pp. 91-96 ◽  
Author(s):  
Danuta Kotnarowska
Keyword(s):  
Experimental Investigation ◽  
Grain Size ◽  
Particle Velocity ◽  
Erosive Wear ◽  
Wear Intensity ◽  
Polymeric Coating ◽  
Degree Polynomial ◽  
Acrylic Coating ◽  
The Moment ◽  
Free Falling

The paper deals with experimental investigation of erosive wear of acrylic coating. The research was carried out on the erosive wear under the influence of alundum particles (grain size of 0.6 – 0.7 mm) striking the coatings at the angle of 45 degrees. It was established that intensity of the erosive wear (under the influence of free falling alundum particles) essentially depends on velocity of erosive particle at the moment of its impact against coating surface. For example, for the lowest velocity value (3.6 m/s) at the moment of impact, erosive wear intensity was equal to 0.4 mm/kg, while for the largest velocity value (5.3 m/s), the intensity doubled in magnitude. The characteristic of erosive wear intensity, depending on erosive particle velocity, was generated by using second-degree polynomial.

AN INVESTIGATION OF THE INFLUENCE OF CLIMATIC FACTORS ON THE EROSIVE WEAR KINETICS OF POLYMER COATINGS

Tribologia ◽  
2016 ◽  
Vol 268 (4) ◽  
pp. 115-125
Author(s):  
Danuta KOTNAROWSKA ◽  
Andrzej KOTNAROWSKI
Keyword(s):  
Grain Size ◽  
Climatic Factors ◽  
High Surface ◽  
Surface Hardness ◽  
Surface Profile ◽  
Erosive Wear ◽  
Epoxy Coatings ◽  
Mean Grain Size ◽  
Resistance Decrease ◽  
20 Nm

The paper presents investigation results concerning the influence of the modification with nanoparticles of silica (of mean grain size 12 nm or 20 nm) or aluminium trioxide (20 nm) of the structure of epoxy coatings on their resistance to climatic factors and the action of erosive particles. Epoxy coatings aged in natural climatic conditions showed an erosive resistance decrease with ageing. The erosive resistance decrease was accompanied by a hardness decrease as well as surface roughness increase. The highest resistance to erosive wear after 3 years of ageing revealed coatings modified with aluminium trioxide nanoparticles, while the lowest one showed coatings modified with silica nanoparticles of 12 nm mean grain size. Nanocoatings modified with aluminium trioxide nanoparticles also had the highest resistance to ageing; which was proven by the lowest increase of Ra and Rz surface profile parameter values with time, as well as by a high surface hardness, which was higher than hardness of new unmodified coatings.

INFLUENCE OF CLIMATIC AGEING ON EROSIVE WEAR KINETICS OF POLYMER NANOCOATINGS

Tribologia ◽  
2018 ◽  
Vol 278 (2) ◽  
pp. 57-65 ◽  
Author(s):  
Danuta KOTNAROWSKA
Keyword(s):  
Grain Size ◽  
Silica Nanoparticles ◽  
Surface Topography ◽  
Erosive Wear ◽  
High Hardness ◽  
Wear Intensity ◽  
Alumina Nanoparticles ◽  
Polyurethane Coatings ◽  
20 Nm ◽  
Kinetics Of

The paper presents the results of erosive resistance investigation carried out on three-layer epoxy-polyurethane coating systems of different polyurethane top coat composition. Alumina nanoparticles with a grain size of 20 nm or silica nanoparticles with a grain size of 12 or 20 nm were applied for the top coat modification. Coating systems with top coats modified using silica nanoparticles with the grain size of 12 nm (nanocoatings) revealed the highest erosive resistance, whereas the lowest one was observed in the case of coating systems with unmodified top coats. Lower erosive wear intensity of nanocoatings follows on their relatively high hardness, as well as low surface roughness. Moreover, nanofillers contained in the top coat reduce the development of defects (pores, cracks) in its structure, increasing the erosive resistance of the coatings. Climatic ageing substantially influenced the formation of polyurethane coatings surface topography. Polyurethane coatings modified with nanofillers showed less change in their surface topography than did unmodified coatings. Therefore, the modification of polyurethane top coats with nanofillers decreases their surface susceptibility to destruction.

Grain size effects on the wet erosive wear of high-purity polycrystalline alumina

Wear ◽  
1994 ◽  
Vol 172 (1) ◽  
pp. 41-48 ◽  
Author(s):  
M. Miranda-Martinez ◽  
R.W. Davidge ◽  
F.L. Riley
Keyword(s):  
Grain Size ◽  
High Purity ◽  
Size Effects ◽  
Erosive Wear ◽  
Polycrystalline Alumina ◽  
Grain Size Effects

Influence of CaO–SiO2 ratio on the chemistry of intergranular films in liquid-phase sintered alumina and implications for rate of erosive wear

2001 ◽  
Vol 16 (3) ◽  
pp. 652-665 ◽  
Author(s):  
Rik Brydson ◽  
Peter C. Twigg ◽  
Fiona Loughran ◽  
Frank L. Riley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Size ◽  
High Resolution ◽  
Grain Boundaries ◽  
Strong Dependence ◽  
Erosive Wear ◽  
Wear Rates ◽  
Aspect Ratios ◽  
Transmission Electron

Polycrystalline aluminas sintered with 10 wt% additions of calcium oxide (CaO) and silica (SiO2) in varying molar ratios were fabricated via precipitation, calcination, and hot pressing. Alumina microstructures were analyzed by scanning electron microscopy in terms of their mean grain size, grain size distribution, and grain aspect ratios. High-resolution transmission electron microscopy (HRTEM) showed the presence of an amorphous intergranular glassy phase at two- and three-grain boundaries. The intergranular film width at two-grain boundaries, determined by HRTEM, appeared to vary with the [CaO]:[SiO2] ratio of the additive as did the chemical composition and local chemistry, determined by high-resolution analytical transmission electron microscopy and scanning transmission electron microscopy (using both energy dispersive x-ray and electron energy loss spectroscopy). The factors influencing the erosive wear rate are discussed including the chemistry and associated fracture energy of the intergranular glassy film. Wet erosive wear rates of the densified materials were determined and had a strong dependence on the [CaO]:[SiO2] ratio in the additive.

Effect of WC Grain Size and Content on Erosive Wear of Manual Arc Welded Hardfacings with Low-Carbon Ferritic-Pearlitic Steel or Stainless Steel Matrix

2016 ◽  
Vol 674 ◽  
pp. 213-218 ◽  
Author(s):  
Egidijus Katinas ◽  
Maksim Antonov ◽  
Vytenis Jankauskas ◽  
Remigijus Skirkus
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Wear Resistance ◽  
Kinetic Energy ◽  
Wear Rate ◽  
Erosive Wear ◽  
Impact Angle ◽  
Steel Matrix ◽  
Low Carbon ◽  
Wear Rates

The erosive wear resistance of manual arc welded hardfacings with low-carbon or stainless steel matrix, varied WC grain size (0.23-0.61 mm) and varied WC content (max. 40 wt. %) was studied. Electrodes were produced by JSC “Anykščių varis“ company (Lithuania). Testing was performed according to GOST 23.201-78 standard using the Centrifugal Accelerator of Kleis (CAK). Test parameters were as following: room temperature; silica sand with particles size 0-0.6 mm; particle impact velocity – 10, 30, 50 and 80 ms-1; impact angles – 30° and 90°.It was found that there is only minor (usually not more than 2 times) effect of WC grain size and content on erosive wear of studied hardfacings. There is strong effect of velocity on wear rate. The graph showing the effect of abrasive particle‘s kinetic energy on wear rate is provided. It was found that the wear rate increases 2.8 times faster than kinetic energy of abrasive particles. The wear resistance of coatings could be improved by addition of WC when hardfacing is tested with impact angle of 30°. However, for impact angle of 90° the addition of WC into hardfacing has no effect or is even detrimental (leading to the increase in wear rate). The hardfacings with WC grain size in the range from 0.14 to 0.27 mm have the lowest wear rates during testing with impact angle of 30°. A discussion of the wear mechanisms for the hardfacings is provided, based on data and observations obtained by using scanning electron microscopy.

The Influence of Dopants in the Grain Size of Alumina - A Review

2015 ◽  
Vol 820 ◽  
pp. 280-284 ◽  
Author(s):  
Pâmela Milak ◽  
Flávia Dagostim Minatto ◽  
Cristian Faller ◽  
Agenor de Noni Jr. ◽  
Oscar Rubem Klegues Montedo
Keyword(s):  
Grain Size ◽  
Wear Rate ◽  
Strong Influence ◽  
Wear Behavior ◽  
Erosive Wear ◽  
High Technology ◽  
Ceramic Materials ◽  
Final Microstructure ◽  
The Subject ◽  
Broad Understanding

Ceramic materials present interesting properties and generate products that meet engineering requirements referring to this class for several applications. Aluminum oxide is a very good example of this class of materials, being applied widely in high technology areas especially where the abrasive and erosive wear are strongly demanded. Many factors interfere on the wear of alumina: material composition, characteristics of the used oxides, and the manufacturing process that defines the final microstructure. It is know that the grain size of the alumina has a strong influence on the wear rate and is the focus of several studies. The grain growth during sintering as well as the diffusion process can be controlled by using dopants in the alumina composition. Thus the aim of this paper is to present a review about the dopants interference on the grain size of alumina, which in turn influences the wear behavior of the alumina. The results described allow broad understanding on the subject

Effect of Shock Loading on the Microstructure of Uniloy 326

1974 ◽  
Vol 32 ◽  
pp. 504-505
Author(s):  
K. P. Staudhammer ◽  
L. E. Murr
Keyword(s):  
Grain Size ◽  
Shock Loading ◽  
Current Investigation ◽  
Two Phase ◽  
05 C ◽  
Shock Deformation ◽  
Heat Treated

The effect of shock loading on a variety of steels has been reviewed recently by Leslie. It is generally observed that significant changes in microstructure and microhardness are produced by explosive shock deformation. While the effect of shock loading on austenitic, ferritic, martensitic, and pearlitic structures has been investigated, there have been no systematic studies of the shock-loading of microduplex structures.In the current investigation, the shock-loading response of millrolled and heat-treated Uniloy 326 (thickness 60 mil) having a residual grain size of 1 to 2μ before shock loading was studied. Uniloy 326 is a two phase (microduplex) alloy consisting of 30% austenite (γ) in a ferrite (α) matrix; with the composition.3% Ti, 1% Mn, .6% Si,.05% C, 6% Ni, 26% Cr, balance Fe.

Aspects of microanalysis in a transmission electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 510-511
Author(s):  
R. Sinclair ◽  
B.E. Jacobson
Keyword(s):  
Grain Size ◽  
Electron Beam ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Transmission Electron Microscope ◽  
Vapor Deposition ◽  
Critical Currents ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron

INTRODUCTIONThe prospect of performing chemical analysis of thin specimens at any desired level of resolution is particularly appealing to the materials scientist. Commercial TEM-based systems are now available which virtually provide this capability. The purpose of this contribution is to illustrate its application to problems which would have been intractable until recently, pointing out some current limitations.X-RAY ANALYSISIn an attempt to fabricate superconducting materials with high critical currents and temperature, thin Nb3Sn films have been prepared by electron beam vapor deposition [1]. Fine-grain size material is desirable which may be achieved by codeposition with small amounts of Al2O3 . Figure 1 shows the STEM microstructure, with large (∽ 200 Å dia) voids present at the grain boundaries. Higher quality TEM micrographs (e.g. fig. 2) reveal the presence of small voids within the grains which are absent in pure Nb3Sn prepared under identical conditions. The X-ray spectrum from large (∽ lμ dia) or small (∽100 Ǻ dia) areas within the grains indicates only small amounts of A1 (fig.3).

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