• 한국기계가공학회지
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• 제7권3호
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• pp.110-114
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• 2008

In this study, to examine the friction coefficient and wear amount of dental prosthesis, pin-on-disk type wear test were at room temperature. Vickers hardness and fracture toughness measurement of dental materials were preformed. Microscopic observations on worn surfaces of specimens were conducted by SEM. The friction coefficient of dental material was investigated according to weight and slinging velocity. dental material have investigated composed to nature teeth.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제27회 춘계학술대회
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• pp.335-341
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• 1998

In this study, the dynamic characteritics in various loading methods for wear tester were investigated experimentally. As for the dead-weight, the pneumatic, and the hydraulic method, the load control performance against external disturbances was estimated under the several loading conditions like the different sliding speed, the varied normal load, and the misaligument. The hydraulic loading method showed the most stable loading performance of all the loading methods in the experiment.

• Tribology and Lubricants
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• 제25권4호
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• pp.243-249
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• 2009

A magnetic clutch consists of pulley and disk. It delivers and isolates the power needed for the operation of the compressor used in automotive air conditioning system. To improve the performance, efficiency and durability of automotive air conditioning system, appropriate design of pulley, disk and system working parameters(the magnitude of magnetic force, and so on) is necessary. For that goal, it is required to understand the friction characteristics of magnetic clutch for the initial operating time. In this study, friction tests were carried out in order to investigate the effect of sliding velocity on the friction characteristics of magnetic clutch using pin-on-disk type friction and wear tester. For experiments, pulley and disk used in real automotive air conditioning system were considered. Friction experiments were conducted under various sliding velocities, and coefficients of kinetic friction were obtained. Under the experimental conditions considered in this study, the coefficients of kinetic friction increased with the increase of test number(sliding distance) and decreased with the increase of sliding velocity.

• 한국정밀공학회지
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• 제17권3호
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• pp.149-157
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• 2000

Tool wear in the shearing process such as blanking, piercing and trimming is very important, because it has great effects on the dimensional accuracy, working efficiency and economy. Most of tools in the shearing process have the coated layer at surface fur good wear and corrosion resistance. When the surface of tool is teated, the wear Phenomena of coated surface layer and inner layer may be different. This paper describes a computer modelling technique by the finite element method in order to investigate the wear mechanism and to predict the wear profile of Ti-N coated tool in piercing process according to the volume of Production. Wear coefficients of the coated layer and inner layer are obtained through Pin-on-Disk wear test, respectively. To verify the effectiveness of the suggested technique, the technique is applied to wear analysis in piercing recess of piston pin and simulation results are compared with experimental ones.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1999년도 제29회 춘계학술대회
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• pp.7-13
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• 1999

An experimental study was performed to discover the effect of silver coating on the frictional behavior of SM45C steel at sliding surfaces. Pure silver was coated the SM45C disk surfaces by a thermal evaporation method. Experiments using a pin-on-disk test-rig was performed under dry air and various humidity conditions. Friction coefficients increased to a high and unstable value after failure of coating, and friction coefficients increased with increasing the thickness of silver coated layer. But optimum coating thickness was not observed.

• 한국정밀공학회지
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• 제20권11호
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• pp.127-133
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• 2003

Pin-on-disk and hardness tests using mechanical components of M-20J aircraft braking system were performed to identify the friction and wear characteristics. The intention of this work was also to analyze a 5-year term maintenance record of an M-20J aircraft. used for flight training at Hankook Aviation University, and to determine the reliability of the brake system of an M-20J aircraft. The mean wear coefficients of the lining sliding against the brake disk were compared between the test and reliability estimation to obtain a predictive wear model.

• 한국표면공학회지
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• 제34권2호
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• pp.125-134
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• 2001

($Ti_{1-x}$ $Cr_{x}$ )N coatings were deposited by an ion-plating method in a reactor with two separate metal sources, Ti and Cr. Ti was evaporated using an electron beam, while Cr evaporation was carried out by resistant heating. The Ti and Cr concentrations in the coatings were controlled by the Ti and Cr evaporation ratio. The coating hardness increased with increasing the Cr content(x) and showed a maximum value of 6,000 HK at around x=0.8. The critical load of the coatings, measured by the scratch test, was around 30 N. The wear resistance properties of the ($Ti_{1-x}$$Cr_{ x}$)N coatings were evaluated using a CSEM pin-on-disk type tribometer. A Cr-steel ball as well as a SiC ball, which had hardness values of 590 HK and 2,600 HK respectively, were used as the pin. After the wear test, the surface morphology, roughness and the concentration of the coatings were investigated, with the main focus being on the effect of wear debris and the transferred layer on the wear behavior.

• 한국산업융합학회 논문집
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• 제23권6_2호
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• pp.917-926
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• 2020

Friction mechanisms is a very important role in the industrial machinery. However, many experiments have been conducted to reduce the loss of energy resources and parts used due to friction because the friction force adversely affects parts, efficiency, noise, and the like of the power unit. Therefore, in this study, the friction coefficient according to the characteristics of the lubricant was measured to find out which Grease Lubricant maintains the low friction coefficient without being most affected by external conditions. A total of five grease lubricants were tested in this study: GHP CAL 301, GHP EP 2, GHP KG 10, GHP HPG 2, and GHP HTG 2. And the friction coefficient was conducted by changing the load conditions (2, 4, 6, 8, 10N) and rotational speed (24, 48, 67, 86, 105, 124, 143, 162vrpm) using a pin-on-disk wear test system. Also, duty number were calculated. As a result, it was confirmed that in all grease lubricants, the speed did not significantly affect the friction coefficient, and it was confirmed that in all lubricants, the size of the friction coefficient decreased as the load increased from a small load to a large load. In addition, it was determined from the experimental results that GHP EP 2 is the most suitable as a grease lubricant and GHP CAL 301 is not the most suitable.

• 대한치과기공학회지
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• 제31권1호
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• pp.63-74
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• 2009

Partial or complete prosthesis is needed when teeth are lost due to various kinds of reason. Artificial teeth recover occlusion instead of natural teeth. Artificial teeth are required of esthetics, fragile resistance and abrasive resistance. Artificial tooth is made of acrylic resin or porcelain. Nowadays, acrylic resin artificial teeth are mainly used. Acrylic resin teeth are occluded with natural teeth, gold alloy, Ni-Cr alloy or porcelain etc. Acrylic resin teeth have similar translucency, gloss of natural teeth. And it has good chemical bond with denture base material, but it has low wear resistance. The aim of this study is to compare wear resistance among several denture teeth(Endura, SR-orthosit-PE, Planustar) and between artificial resin denture teeth and opposing 3 restorative materials(gold, Ni-Cr alloy, porcelain). Wear tests were conducted with a rotating wear testing apparatus(pin-on-disk type wear tester) under conditions of rpm 180, 75 minutes and constant loading of 50N. The upper part was the cusp of maxillary first molar and the lower part was a disk type restorative materials. To make similar oral environment, water was supplied continually. The acrylic resin teeth wear was determined by weighing the cusp each 5 minutes during 75 minutes test. Vicker's hardness tester was used to evaluate the surface hardness of test specimens. The SEM was used to evaluate the wear surfaces. The results were as follows: 1. Wear rates of acrylic resin teeth opposing to the restorative materials were high in order of Porcelain, Gold, Ni-Cr alloy (p<.05). 2. Wear resistance rate opposing to the Porcelain disk, was shown in order of Endura, SR-orthosit-PE, Planustar. The wear rate of opposing to porcelain disk was above two times more than that of other groups (p<.05). 3. Wear resistance rates opposing to the Gold, Ni-Cr alloy disk, was shown in order of Endura, SR-orthosit-PE, Planustar (p<.05). 4. A degree of the surface hardness is directly proportional to the degree of wear resistance. There are statistically significant differences between each groups (p<.05).

• Restorative Dentistry and Endodontics
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• 제24권1호
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• pp.129-135
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• 1999

In this review article, in vivo and in vitro wear test methods which measure the wear of tooth and restorative material were discribed. In vivo test, the criteria of each test were reviewed. The merits and limitations were also commented. In vitro tests, three dimensional scanning methods which scan the occlusal tooth surface three dimensionally were described. Profilometer method, Pin on disk method, laser scanner method were reviewed and the limitations of each test were commented. Additionally, the structer of the three dimensional scanner which has been developed in Zurich university and has been reputated as the most accurate one was described. This study was partly supported by 1997 post-doctoral foreign study program.