THE EFFECT OF ABRASIVE MASS MOISTURE CONTENT ON THE ABRASION-RESISTANT STEEL WEAR RATE

Tribologia ◽  
2019 ◽  
Vol 284 (2) ◽  
pp. 75-82
Author(s):  
Krzysztof Ligier ◽  
Magdalena Lemecha ◽  
Jerzy Napiórkowski
Keyword(s):  
Grain Size ◽  
Wear Rate ◽  
Moisture Content ◽  
Abrasive Wear ◽  
Quartz Sand ◽  
Resistant Steel ◽  
Test Results ◽  
Moisture Contents

This paper presents the results of tests for Hardox Extreme Steel wear rate in an abrasive mass of varying moisture contents. The tests were conducted by the “rotating bowl” method using quartz sand with a grain size of 0.5–1.4 mm. The obtained test results show that an abrasive mass with a moisture content of 7% exhibits the lowest rate of steel abrasive wear. However, the highest wear rate was noted for an abrasive mass with a moisture content of 14%. A further increase in moisture content resulted in a decrease in the steel wear rate.

Machining and Wear of High-Alumina Ceramics for Structural Applications

2009 ◽  
Vol 409 ◽  
pp. 137-144 ◽  
Author(s):  
Stojana Veskovic-Bukudur ◽  
Tanja Leban ◽  
Milan Ambrozic ◽  
Tomaž Kosmač
Keyword(s):  
Grain Size ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Direct Relationship ◽  
Bending Strength ◽  
High Alumina ◽  
Alumina Ceramics ◽  
Large Area ◽  
Structural Applications ◽  
Worn Surfaces

The wear resistances of four standard-grade high-alumina ceramics were evaluated and related to their machining ability. Three of the material grades contained 96% of alumina and 4% of either calcium silicate, or magnesium silicate, or manganese titanate in the starting-powder composition. The nominal alumina content in the fourth material was 99.7%. The specimens were fabricated using a low-pressure injection-molding forming technique, followed by thermal de-binding and sintering. After sintering the four materials differ significantly in their grain size, bending strength and Vickers hardness. No direct relationship between the microstructural parameters and the mechanical properties was found, but there was a grain-size dependence of the surface finish after grinding under industrial conditions. The two silicate-containing ceramics exhibited considerably higher wear resistances than the two silicate-free ceramics, but no direct relationship between the abrasive wear rate during grinding and the cutting time was observed. The cutting ability represents a valuable material characteristic for industrial practice, but it should not be directly used for predicting the wear rate during grinding. Quantitative differences in the cutting time and abrasive wear rate were manifested in the different topographies of the worn surfaces. Cutting resulted in relatively large area fractions of plastically deformed surfaces, whereas pullouts dominated the worn surfaces after grinding.

scholarly journals Effect of WC Grain Size and Abrasive Type on the Wear Performance of HVOF-Sprayed WC-20Cr3C2-7Ni Coatings

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 660
Author(s):  
Qun Wang ◽  
Yingpeng Zhang ◽  
Xiang Ding ◽  
Shaoyi Wang ◽  
Chidambaram Seshadri Ramachandran
Keyword(s):  
Grain Size ◽  
Wear Resistance ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Wear Test ◽  
Binder Phase ◽  
Repeated Impact ◽  
Wear Performance ◽  
The Matrix ◽  
Three Body

In order to investigate the effect of WC grain size on coatings’ properties and abrasive wear performance, a few WC-20Cr3C2-7Ni coatings with three different WC grain sizes were deposited by the high-velocity oxy-fuel (HVOF) thermal spray process. The phase compositions, microstructures, and mechanical properties of the coatings were investigated. Furthermore, the two- and three-body abrasive wear performances of the three coatings were tested by using SiC and SiO2 abrasives, respectively. The results show that all the three coatings were composed of WC, Cr3C2, and the Ni binder as well as the (W,Cr)2C phase. The abrasive wear resistance of the WC-20Cr3C2-7Ni coating monotonously increased with increasing WC grain size when the SiC abrasive was used in the two- and three-body abrasive wear tests. However, the wear resistance trend was reversed when the SiO2 abrasive was used in the three-body abrasive wear test. The specific wear rate of the WC-20Cr3C2-7Ni coating exposed to the SiC abrasive under the two-body abrasive wear test was the largest. The wear resistance of the coatings was more significantly affected by the hardness of the abrasive particles than the size of carbides present within the coating. The high hardness of SiC can cut both the carbide and the binder phase of the WC-based cermet coatings, resulting in a high wear rate, whereas the low hardness of SiO2 cuts and/or scratches the binder initially, and then it dislodges the carbides from the matrix. The dislodged carbides which were subsequently pulled out from the matrix by the repeated impact of the SiO2 abrasives result in a milder wear rate.

Evaluation of a Bulk Drying Model for Peanuts1

1992 ◽  
Vol 19 (1) ◽  
pp. 1-7 ◽  
Author(s):  
M. Parti ◽  
J. H. Young
Keyword(s):  
Moisture Content ◽  
Thin Layer ◽  
Flow Rate ◽  
Test Results ◽  
Air Flow Rate ◽  
Moisture Movement ◽  
Moisture Contents ◽  
Air Temperatures ◽  
Thin Layer Drying ◽  
Drying Model

Abstract Results of a peanut bulk drying model, PEADRY8, have been compared with experimental test results for Virginia-type peanuts. The model describes the peanut pod as two separate components with moisture movement in both liquid and vapor form. The Henderson equation was used to describe the equilibrium moisture contents of the kernel and the hull. The following conclusions were drawn: (1) predicted drying times averaged 11% longer than the observed values; (2) predicted kernel moisture contents at the top of the wagons averaged 5% less than the measured values; (3) predicted hull moisture contents at the top of the wagons averaged 17% higher than the observed values; (4) predicted hull final moisture contents at the top of the wagons average 21% higher than measured values and (5) predicted exhaust air temperatures averaged 1% higher than measured values. An attempt was made to improve the fit of the observed and simulated results by changing the equation to describe the equilibrium moisture contents. The Chung-Pfost equation, compared to the Henderson equation, was more accurate in describing the hull moisture content and less accurate in describing the kernel moisture content history. Changing the reference air flow rate of the thin-layer drying relationship did not give a better fit between the observed and predicted data. Several drying simulations were found to be very sensitive to small changes in either wet-bulb or dry-bulb temperature. Small errors in wet-bulb temperature measurement could account for the predicted drying times for six experiments which were excessively long relative to observed values.

VARIATION OF ELECTRICAL RESISTIVITY OF RIVER SANDS, CALCITE, AND QUARTZ POWDERS WITH WATER CONTENT

Geophysics ◽  
1962 ◽  
Vol 27 (4) ◽  
pp. 470-479 ◽  
Author(s):  
V. V. Jagannadha Sarma ◽  
V. Bhaskara Rao
Keyword(s):  
Grain Size ◽  
Electrical Resistivity ◽  
Moisture Content ◽  
Water Content ◽  
Saturation Index ◽  
Clay Particles ◽  
Moisture Contents ◽  
Grain Sizes ◽  
Critical Moisture

Electrical resistivity variations of samples of graded river sands, calcite, and quartz powders are studied for different moisture contents of varying salinities. The variations exhibit a general hyperbolic trend. For the same grain size, the critical saturation index of a sample is constant and independent of the salinity of moisture content. The smaller the grain size, the larger the saturation index. The critical saturation index of a sample is correlated with its retentive capacity, and it is shown, from studies of the quartz samples, that, for grain sizes of the order of clay particles, the critical moisture would reach 100 percent.

EFFECT OF ABRASIVE PARTICLE SHAPE ON TWO-BODY ABRASIVE WEAR OF STEEL

Tribologia ◽  
2021 ◽  
Vol 294 (6) ◽  
pp. 21-27
Author(s):  
Krzysztof Ligier ◽  
Magdalena Lemecha
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Wear Rate ◽  
Size Distribution ◽  
Grain Shape ◽  
Abrasive Particle ◽  
Test Results ◽  
Natural Sand ◽  
Rate Testing ◽  
Materials Used

This paper presents the results of Hardox Extreme steel wear rate testing using an abrasive mass of varying grain shapes. The tests were conducted by the ASTM G65 method using crushed and natural sand with a grain-size distribution of 0.05–2 mm, obtained from a gravel pit. The abrasive materials used in the tests differed in grain shape, while the particle-size distribution was similar. The test results show that the wear rate in crushed sand is four times higher than that in natural sand, which is attributable to the shape of grains and the geometry of their edges.

Fouled Ballast Definitions and Parameters

2016 ◽  
Author(s):  
Radim Bruzek ◽  
Timothy D. Stark ◽  
Stephen T. Wilk ◽  
Hugh B. Thompson ◽  
Theodore R. Sussmann
Keyword(s):  
Grain Size ◽  
Moisture Content ◽  
Test Results ◽  
Track Geometry ◽  
Fouled Ballast ◽  
Laboratory Test Results ◽  
Track Condition ◽  
International Industry ◽  
Size Type ◽  
Industry Survey

Ballast fouling is a problematic track condition that can lead to inadequate ballast performance. Prioritizing remediation of fouled ballast sites is difficult because no relationship between ballast fouling and track performance exists and fouled ballast performance depends on the amount, grain-size, type, plasticity, and moisture content of the fouling material. This paper provides results of an international industry survey on fouled ballast definitions, parameters, limits/standards, and laboratory test results to aid development of a procedure for quantitatively assessing ballast fouling and assessing the ability to: transmit applied train loads to the subgrade, allow drainage, and maintain proper track geometry as required under §213.103.

scholarly journals Adobe bricks with sugarcane molasses and gypsum to enhance compressive strength in the city Cogua, Colombia

2020 ◽  
Vol 19 (3) ◽  
pp. 358-365
Author(s):  
Lady Sofia Rodriguez Cuervo ◽  
Keyword(s):  
Grain Size ◽  
Compressive Strength ◽  
Aspect Ratio ◽  
Moisture Content ◽  
Sugarcane Molasses ◽  
Test Results ◽  
Accurate Data ◽  
Sand Fraction ◽  
The City

This paper presents a case study over the effect of adobe bricks stabilized with gypsum, sugarcane molasses and both combinations on improving the compressive strength. These bricks were produced by a hand-made process, which was empirical and had not been analyzed. All samples had the same unit weigh and aspect ratio to obtain accurate data. An extensive series of test were conducted on adobe bricks stabilized with gypsum (5%, 10% and 15%), sugarcane molasses (5%, 10% and 15%), and gypsum in combination of sugarcane molasses (5%, 10% and 15%) which were cured for one month. From the test results it is showed that the grain size distribution was not optimum, which led to samples stabilized with gypsum alone and sugarcane molasses alone did not overcome the sample control strength. The former increased the strength, but the later decreased it. Although, the sample stabilized with 2.5% gypsum and 2.5% sugarcane molasses had the best strength (2.15 MPa). This case study will be useful to better understand the compressive strength on adobe bricks stabilized depends on percentage of clay and sand fraction, moisture content, and percentage of stabilizer, which means that natural stabilizers could be an environmental solution to improve mechanical behavior.

scholarly journals Effect of speed, die sizes and moisture contents on durability of cassava pellet in pelletizer

2016 ◽  
Vol 61 (No. 1) ◽  
pp. 35-39 ◽  
Author(s):  
O.B. Oduntan ◽  
O.A. Koya
Keyword(s):  
Moisture Content ◽  
Processing Plant ◽  
Processing Conditions ◽  
Test Results ◽  
Optimum Conditions ◽  
Pellet Quality ◽  
Cassava Flour ◽  
Moisture Contents ◽  
Blend Ratios ◽  
Suitable Processing

The effect of pre-processing conditions such as speed, die sizes and moisture content on durability of cassava flour was investigated. Densification of cassava flour was done by pelletizing the flour through die and it is necessary to determine optimum conditions for designing and constructing a suitable processing plant. The flour was mixed with water at different blend ratios to form cassava mash of different moisture contents. The pellet quality was evaluated in terms of the durability of the pellets against the moisture content of the mash (18, 20 and 22% w.b.), die size (4, 6 and 8 mm) and the screw speed (90, 100 and 120 rpm). Test results showed that maximum durability of 84.437% was recorded at 20% (w.b.) moisture content using 4 mm die and low durability of 61.26% with using 8 mm die at 18% (w.b.) moisture content. The durability result shows that it decreased with increase in die size. Statistical analysis revealed that the die size had significant (P ≤ 0.05) effect on the durability.

The effect of abrasive grain size of sad in liquid on abrasive wear rate of metal surface

1999 ◽  
Vol 2 (2) ◽  
pp. 31A-42A
Author(s):  
Gailan Ismaeel Hassan ◽  
◽  
Shawnm Rashid Jalal ◽  
Keyword(s):  
Grain Size ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Metal Surface ◽  
Abrasive Grain

scholarly journals Impact of Moisture Content on the Dynamic Failure Energy Dissipation Characteristics of Sandstone

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Aihong Lu ◽  
Shanchao Hu ◽  
Ming Li ◽  
Tianzhu Duan ◽  
Bing Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Elastic Modulus ◽  
Energy Dissipation ◽  
Surface Energy ◽  
Moisture Content ◽  
Rock Masses ◽  
Moisture Contents ◽  
Dry Conditions ◽  
Moisture Conditions

Rockburst frequently occurs in deep underground engineering, which poses a threat to safety and causes economic losses. Water injection into surrounding rock masses is an effective method for preventing rockburst, and the moisture content of rocks is significant for assessing the probability of rockburst. However, the majority of studies focus on the relationship between the macromechanical properties of rock masses under static loads and the moisture content of rock masses and seldom explore the impact of moisture variation (under dynamic loads) on the mechanical properties and energy dissipation. In this paper, the mechanical properties and energy dissipation of sandstone with different moisture contents have been experimentally investigated by the split Hopkinson pressure bar (SHPB) test. The test results indicate that the peak strength, dynamic elastic modulus, and unloading elastic modulus of sandstone in dry conditions are considerably larger than those in moisture conditions, and the three parameters linearly decrease as the moisture content increases from 0% to 2.58%. The distribution law of sandstone fragments with different moisture contents has been investigated by sieving test fragments with different grain sizes of grading sieves. The results show that the percentage of large grain size fragments incrementally decreases, and the percentage of small grain size fragments incrementally increases with moisture contents from 0% to 2.58%. When the moisture content ranges from 2.01%∼2.58%, the fractal dimension linearly increases, which indicates that the higher the moisture content is, the larger the dimension of the broken sandstone is. The calculation results for energy indicate that the sandstone energy attains the peak value with 0% moisture content. When the moisture content ranges from 2.01%∼2.58%, the reflected energy increases, and the transmitted energy and dissipated energy linearly decrease. In addition, the surface energy of the sandstone with different moisture contents has been investigated by converting fragments into spheres with the corresponding size. The results indicate that the smallest surface area of sandstone is obtained in dry conditions, but its surface energy in dry conditions is larger than that in moisture conditions. When the moisture ranges from 0% to 2.58%, due to 3% illite and 2% chlorite clay minerals reacting with different proportions of moisture, the surface areas of sandstone fragments linearly increase and the surface energy of sandstone linearly decreases.

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