• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.5
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• pp.88-92
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• 2002

This research is about slurry wear of SM45C and SUS304, which using standard sand and KUM river sand. The results are as follows ; 1. Mass loss rates of both standard sand and KUM river sand were linearly increased as increasement of time and velocity. 2. The average diameter of sand from relatively, less wear rate and portion of larger particles. 3. Wear resistance was linear with time and velocity of liquid jet regardless of type of sand. Also, it was able to evaluate with the formula, $HV^2$/E calibrated with n, the velocity index. 4. The wear surface in liquid jet experiment was smooth. The maximum wear depth was observed at the location 2~4mm apart from the center in the condition of $90^{\circ}$ of collision angle 6mm of nozzle diameter, and 20mm of collision distance. The sectional shape in radial appeared as 'W'shape.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.798-801
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• 2001

This research is about slurry wear of SM45C and SUS304, which using standard sand and KUM river sand. The results are as follows ; 1. Mass loss rates of both standard sand and KUM river sand were linearly increased as increasement of time and velocity. 2. The average diameter of sand from relatively, less wear rate and portion of larger particles. 3. Wear resistance was linear with time and velocity of liquid jet regardless of type of sand. Also it was able to evaluate with the formula, HV2/E calibrated with n, the velocity index. 4. The wear surface in liquid jet experiment was smooth. The maximum wear depth was observed at the location, 2~4mm apart from the center in the condition of 90$^{\circ}$of collision angle 6mm of nozzle diameter, and 20mm of collision distance. The sectional shape in radial appeared as 'W' shape.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.429-430
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• 2002

In this study, three kinds of brake: discs including two coated brake discs and one steel disc were tested under the same experimental conditions on a reduced scale braking test bench. Plasma spray coating technique was used to coat ceramic powder on the discs. In the test, four commercial sintered brake pads were coupled with discs. Ceramic coated discs have shown good stability in friction coefficient at high speed and high energy braking conditions. However, ceramic coated discs caused more wear loss of pad mass than the steel disc. It was shown that thermal barrier effect in ceramic coated discs adjusted the thermal partition between pad and disc. Steel disc showed fluctuating friction coefficient at high speed but less wear loss of pad mass than ceramic coated discs.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.04a
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• pp.97-107
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• 1998

Three different kinds of brake discs including two coated brake discs and one steel disc were tested under the same experimental conditions on a reduced scale braking test bench. Braking test bench was specially designed to analyse thermo-mechanical and frictional behaviors of two sizes of brake discs in stop and hold braking modes. And Plasma spray coating technique was used to coat ceramic powder on the discs. In the test four commercial brake pads were coupled with discs. Ceramic coated discs had shown good stability in friction coefficient at high speed and high energy braking conditions. But they caused large pad mass wear loss compared with the steel disc. It was shown that thermal barrier effect in ceramic coated discs adjusted the thermal partition between pad and disc. For a steel disc, it had shown fluctuating friction coefficient at high speed but a fittie pad mass wear loss compared with ceramic coated discs.

• Journal of Korea Foundry Society
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• v.17 no.5
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• pp.472-479
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• 1997

The effect of size and mass fraction of SiC particulate on the fatigue and wear have been investigated for semi-liquid formed SiCp/AZ91HP Mg composites. In the study, different particulate sizes of 7, 20, $50 {\mu}m$ were prepared with various mass fraction for sample preparation. By tension-tension fatigue tests, whose procedures are standardized in ASTM standard 647E-93, the da/dN vs. ${\Delta}K$ curves were obtained. Also, the crack propagation paths were observed by optical microscope. As a result of wear test, specific wear loss is decreased with increasing mass fraction and particulate size. Specific wear loss of 30 mass% $50 {\mu}m$ SiC reinforced Mg composite is compared to SKD11.

• Tribology and Lubricants
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• v.18 no.4
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• pp.305-311
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• 2002

Three different kinds of brake discs including two coated brake discs and one steel disc were tested under the same experimental conditions on a reduced scale braking test bench. A braking test bench was specially designed to analyse thermo-mechanical and frictional behaviors of two types of brake with different sizes in stop and hold braking modes. Plasma spray coating technique was also used to coat the discs with ceramic powder. During the test four commercial brake pads were coupled with discs. Ceramic coated discs showed good stability in friction coefficient at high speed and high energy braking conditions. But they caused large wear loss of pad mass compared with the steel disc. It was shown that thermal barrier effect in ceramic coated discs adjusted the thermal partition between pad and disc. For a steel disc. it showed fluctuating friction coefficient at high speed but small wear loss of pad mass compared with ceramic coated discs.

• Tribology and Lubricants
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• v.39 no.6
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• pp.250-255
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• 2023

This study applies various surface patterns to minimize material loss in construction equipment that is subject to severe wear due to sand, such as the wear-resistant steel plates of dump trucks or the teeth of excavators. The relationship between surface morphology and wear behavior is investigated using PLA+ polymer to observe the effect of the surface pattern. Five types of samples - smooth, concave, convex, wavy concave, and wavy convex designs - are created using a 3D printer. A wear experiment is conducted for a duration of 3 h using 6.5 kg of abrasive particles. The mass loss of the samples after the experiment is measured to assess the extent of wear. Additionally, the surface morphology of the samples before and after the experiment is analyzed using SEM and confocal microscopy. The study results reveal that the smooth design exhibits the highest wear loss, whereas the concave and wavy concave designs show relatively lower wear loss. The convex and wavy convex designs exhibit varying contact areas with the abrasive particles depending on the surface pattern, resulting in different levels of wear. Furthermore, a comparison between the experimental results and DEM simulations confirms the observed wear trends. This study reveals the relationship between wear damage according to surface pattern shape and is expected to be of substantial help in the analysis of wear and tear on agricultural and heavy equipment.

• Tribology and Lubricants
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• v.33 no.1
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• pp.31-35
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• 2017

Recently, international attention has been focused on the development of non-traditional energy resources such as shale gas and oil sands, due to the steep increase in the demand for natural resources. The materials incorporated in an oil gas plant module experience extreme environments, and are prone to various problem such as fracture, corrosion and abrasion due to low-temperature brittleness. In order to improve the plant life, it is necessary to perform characteristics study and performance evaluation of the materials. In particular, this paper explains the main set of materials which are most frequently used in oil sands plant project. In order to investigate wear characteristics, the authors carried out abrasive wear tests of TP 316, stainless steel and SS 400, structural rolled steel. For the analysis of the abrasive wear resistance of an oil sands plant, the authors carried out the test according to ASTM G 105 "Standard Test Method for Conducting Wet Sand/Rubber Wheel Abrasion Test" standard guidelines. The authors have derived the results from the data associated with the loss of mass with respect to wear rate. During the test, for a given wear length for 10,000 revolutions, the rotational speed and applied force of the rubber wheel were varied.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.469-477
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• 2002

One of the major deficiencies of composite restorative resins is their insufficient resistance to wear. Of the multitude of factors that have been associated with wear, subsurface degradation within the restoration is considered to be one. The aim of this study was to evaluate the resistance to degradation of four commercial composite resins in an alkaline solution. The brands studied were Z100(3M), Clearfil AP-X(Kuraray), Tetric Ceram(Vivadent), Aelit flo(Bisco). Resistance to degradation was evaluated on the basis of the following parameters: (a) mass loss(%) - determined from pre-and post-exposure specimen weights: (b) Si loss(ppm) - obtained from ICP-AE analysis of solution exposed to specimens; and (c) degradation depth(${\mu}m$) - measured microscopically (SEM) from polished circular sections of exposed specimens. The results were as follows: 1. The sequence of the mass loss was in ascending order by AE, EL, TC, Z100. There was statistically significant difference of mass loss between AE, CL group and TC, Z100 group(p<0.05). 2. The sequence of the degree of degradation layer depth was in ascending order by AE, CL, TC, Z100. But there was no statistically significant difference of degree of degradation layer depth between AE and CL(p<0.05). 3. For the Si concentration, Z100 was the highest of all. 4. The correlation coefficient between mass loss and degradation depth was relatively high(r=0.71 p<0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.2
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• pp.370-378
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• 2000

The composite restorative resins have their insufficient resistance to wear. The subsurface degradation within the restoration is considered to be associated with wear. The aim of this study was to evaluate the resistance to degradation of six commercial composite resins in an alkaline solution. The brands studied were Clearfil APX(Kuraray), Heliomolar(Vivadent), Surefil(Dentsply), TPH(Dentsply), Tetric Ceram(Vivadent), and Z100(3M). Preweighed discs of each brand were exposed 0.1N NaOH solution at $60^{\circ}C$. After 14 days they were removed, neutralized with HCL, washed with water and dried to constant mass at $60^{\circ}C$. Resistance to degradation was evaluated on the basis of the following parameters: (a) mass loss(%) - determined from pre-and post-exposure specimen weights; (b) Si loss (ppm)-obtained from ICP-AE analysis of solution exposed to specimens; and (c) degradation depth$({\mu}m)$ - measured microscopically (SEM) from polished circular sections of exposed specimens. The results were as follows: 1. The mass loss was in descending order by Z100, TC H, S, CL, TPH and in the range of $0.45\sim3.64%$ 2. The degradation layer depth was in descending order by H, Z100, S, TC, TPH, CL and in the range of $10.85\sim73.38{\mu}m$ 3. For the Si concentration, Z100 was the highest of all 4. The highly significant correlation(r=0.81, p<0.05) was observed between mass loss and degradation depth. 5. Under scanning electronmicroscopy, the degradation of connection between resin matrix and fillers was observed 2 weeks after soaking in NaOH solution.