• Korean Journal of Materials Research
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• v.14 no.1
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• pp.59-66
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• 2004

In the present study, ceramic brake pads without fiber phases were manufactured by the low temperature heat treatment below$ 700 ^{\circ}C$. The manufacturing parameters of ceramic brake pads and those levels were investigated by the analysis results of signal-to-noise ratios, ANOVA based upon the Taguchi method. The ceramic brake pads prepared in the Mg experiment had a friction coefficient of 0.30～0.55 very close to the target coefficient (0.35～0.45) of commercial brake pads utilized in the automobiles. The frictional properties of ceramic brake pads could be stabilized with the adjustment of amounts of lubricating additives. The optimum preparation conditions as well as batch formulations for the fabrication of non-fibrous ceramic brake pads were finally determined using Taguchi method in this study.

• 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.

• 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.

• 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.

• Journal of Auto-vehicle Safety Association
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• v.12 no.1
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• pp.26-32
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• 2020

The luxury car market has been steadily growing for the last 10 years and it might keep expanding in the future. Furthermore, it is expected to be a very competitive market because luxury cars are considred to reflect the technology level of motor companies. For this reason, it is very important for motor companies to improve performances of luxury vehicles. However, it takes years for the companies to increase the technology level for the high performances. In this paper, we aim to analyze the technologies for high quality brake perfomances through investigation of two luxury vehicle models and develop a new high performance brake system. First, we found out a variety of effective factors for the high performances. Second, we conducted the brake performance analysis to figure out the relationship between brake effort and brake feeling. Finally, we develped the new brake system using carbon ceramic composite materials to satisfy the high quality brake performances.

• Tribology and Lubricants
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• v.27 no.2
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• pp.95-100
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• 2011

The brake disc materials for railway vehicle have been mainly used cast-iron. The brake disc and pad should be light, resist to a thermal crack and absorb enough friction energy. In order to satisfy this requirement, aluminum alloy brake disc for railway vehicle has been newly developed. The aluminum itself has not been considered the friction material for railway vehicle. However, in the case of aluminum composite with dispersed ceramic particles, friction characteristics, resistance to wear and heat are much improved. In the present study, aluminum composite brake disc of 20% ceramic particle and three kinds of organic pads have been tested in dynamometer. The results show that Al MMC brake disc and pad have good friction coefficient and wear rate, and thermal cracks in brake disc have not been initiated. Also, the Al MMC brake disc can be applied to railway vehicle of 150 km/h.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.4
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• pp.39-45
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• 2022

In this study, it was verified that carbon-ceramic brake discs can replace existing cast-iron brake discs of the same size. In addition, a method of pretreating carbon fiber to secure heat dissipation characteristics while using a small amount of carbon fiber was established. The thermal conductivity and bending strength characteristics were analyzed according to the carbon content, and brake braking tests were conducted. Through pretreatment, the maximum temperature was lowered by 16 ℃ compared to the case using only carbon fiber, and the cooling rate was improved by approximately 10% compared to metal brake discs. However, the total heat capacity increased as the mass increased owing to the reaction. Thus, the measured temperature was higher than that of the metal brake disc; therefore, additional research is required.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.100-105
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• 2008

Cross-drilling on the brake disc is generally known as a way of improving cooling efficiency. In other theories, cross-drilled holes act like a path of gas or water and are also known that they can reduce fading and wetting of brake rotors. However, in disc rotors with cross-drilling, thermal crack phenomena have been reported more frequently and more manufacturing cost should be paid than non cross-drilled disc rotors. In this study, to examine various effects of cross-drilling on the brake disc, two kinds of brake disc rotors, cross-drilled and non cross-drilled, were used in computational fluid dynamic analyses and dynamometer tests.

• Journal of Auto-vehicle Safety Association
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• v.11 no.1
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• pp.23-29
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• 2019

Recently, use of composite materials has been increasing for body structures and chassis parts in the car industry because of weight reduction effect and excellent mechanical thermal characteristics. However, application of composite materials in brake system is very difficult because it is hard to obtain enough brake performance due to low heat storage capacity of the composite materials. In this paper, we will present new carbon ceramic composite disc with high flow characteristic. To obtain this characteristic, new vent structures were designed by using ARIZ method and substance-field model analysis. The flow effect of these vent structures on the brake performance was verified by pugh matrix and cooling test. The test results show improvement of cooling performance up to $30^{\circ}C$. Finally, These results will improve brake the reliability of the brake performance for the high performance vehicles and electric vehicles.

• Tribology and Lubricants
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• v.24 no.4
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• pp.163-169
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• 2008

Tribological properties of ceramic brake discs were investigated using a commercial friction material. The discs were manufactured by liquid silicon infiltration (LSI) into a C-C preform. The disc surface was modified by two different methods, producing sliding surfaces with chopped carbon fibers and carbon felt. In addition, the composition of the surface was also changed. Friction characteristics of the discs were examined using a 1/5 scale dynamometer. Results showed that the type and composition of the disc surface significantly affected the level of braking effectiveness and high temperature brake performance. The discs with felt surfaces showed higher friction levels than those with chopped fiber surfaces and SiC tended to increase the friction level while C lowered the friction coefficient. The ceramic disc was more sensitive to the deceleration rate than gray iron, showing high speed sensitivity.