• Tribology and Lubricants
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• v.19 no.1
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• pp.31-35
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• 2003

This paper reports the studies on the wear-corrosion behavior of ductile cast iron in the various pH environments. In the variety of pH solutions, corrosion and wear-corrosion loss of GCD 600 were investigated. Also, the anodic polarization test of GCD 600 using potentiostat/galvanostat was carried out. And rubbed surface of GCD 60 using scanning electron micrographs after immersion and wear-corrosion test was examined in the environment of various pH values. The main results are as following In alkali zone, the wear-corrosion loss of GCD 600 increases, but corrosion loss decreases. The unevenness and crack of wear-corrosion surface in neutral zone becomes duller than that in alkali zone. As the corrosive environment is acidified, wear-corrosion behavior of GCD 600 with passing immersion time becomes sensitive.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.06a
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• pp.339-344
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• 1999

In this paper, the hardness and wear characteristics of the head hardened rail, which is made by thermite and gas pressure weldings have been presented. In general, the wear rate of the gas pressure welded rail is high and uniform compared with that of thermite welded rail. The results indicate that HH 370 welded rail shows stable in hardness and low wear rate compared with other two welded rails. The hardness of head hardened rails shows uniformly distributed along the welded zone, thermally affected zone and a base matrix.

• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.3
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• pp.259-268
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• 2012

This study suggests quantitative guidelines for inside clothing temperatures to improve the heat tolerance of 20's females in summer. First, the inside clothing temperatures ($T_{cl}$) of each subject was measured in daily use. The subjects were asked to record subjective thermal sensations, clothing items worn, clothing weight, and activities during an experiment designed to determine the comfort zone of $T_{cl}$. In a thermally neutral state, the comfort zone of $T_{cl}$ was decided on a mean value $T_{cl}{\pm}1{\sigma}$. Second, the subjects were asked to wear clothing that would enable them to feel 'slightly warm but still comfortable'. The rest of the processes were the same as previous steps that were designed to understand the way and degree of clothing control. The comfort zone of $T_{cl}$ was decided in the same manner as the previous step. The two comfort zones were combined and named the combined comfort zone of the definitive comfort zone. The results were as follows: 1. Thermally comfortable $T_{cl}$, Hcl were $34.0{\pm}1.1^{\circ}C$, $40{\pm}9%%RH$ and the thermally comfortable ambient climate was $25.0{\pm}1.6^{\circ}C$, $53{\pm}7%$RH. 2. When subjects were asked to wear 'slightly warm but still comfortable', there were difference in thermally comfortable $T_{cl}$, clothing weight and clothing layer by subject. 3. In this study, the optimal $T_{cl}$ was decided on the mid-point of the definitive comfort zone of $T_{cl}$.

• Fashion & Textile Research Journal
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• v.9 no.4
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• pp.380-390
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• 2007

The purpose of this study(Part I) was to provide the guidance in more objective and proper clothing design and wearing rule to make good image making by analysis of fashion sensibilities about adult women's town wear in unlimited circumstance. The specific objectives were; 1)to investigate about fashion sensibility of women's town wear at season 2)to investigate about fashion sensibilities of women's town wear of properties which are age, marriage or not, job, average income per month, and schooling. 3)to compare fashion sensibility between Good and Bad women's town wear. The collected photos at shopping mall, department stores, and churches(S/S, F/W:2004.4.28~2005.5.1) were prepared removing face and background that can affect in estimator and attached on gray board. To investigate fashion sensibilities, the stimulus were 80 photos('good':40, 'Bad':40). The questionnaire consisted of bi-polar 25 pairs adjective scale of fashion sensibilities was distributed 60 female(20's~40's) living in Busan. The data were analyzed by t-test, ANOVA, and Scheffe. The results of this study are summarized as follows; For fashion sensibilities at 'Good' and 'Bad' wear, the variances(season, age, marriage or not, job, average income per month, and schooling) are important. Especially, the fashion sensibility at 30's women are very unique and importance age zone to catch both young women's fashion sensibility and old women's fashion sensibility, Through that age zone, we could read women's various fashion sensibility and prospect complicate consumers' fashion mind. This study result will be utilized in the clothing design for target age zone of women's town wear, database of wearing rule and good image making, and planning fashion marketing strategies.

• Korean Journal of Materials Research
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• v.3 no.1
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• pp.58-64
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• 1993

The degree of work hardening in the subsurface zones varied with the experimental conditions under the rolling contact fatigue wear test of high carbon Cr-Ti alloy steel was evaluated by the distribution of residual stresses. Surface residual stresses before the test did not affect the wear property. Surface residual stresses after the test decreased by the increase of contact stress and running. velocity. but the maximum compressive residual stress and its depth of saturation in the subsurface zone increased. The relationship between these experimental results and the distribution of the theoritical shear stress was also discussed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.3
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• pp.636-645
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• 1990

Analytically induced wear mechanism of elastic body under Hertzian contact is applied in acutual wear test of ceramics. There are two types of wear in ceramics, a large scale wear and a small scale wear. The large scale wear is commensurable with Hertzian contact area and the small scale wear with real contact area. Nondimensional parameter, S$_{c}$, is introduced and fully examined to estimate or predict wear rate of ceramics. Ceramic wear for S$_{c}$.leq.0.8 is in small scale wear and for S$_{c}$;geq.1.6 in large scale wear. wear.

• Korean Journal of Materials Research
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• v.15 no.1
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• pp.61-65
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• 2005

The titanium $diboride(TiB_2)$ has high strength(750MPa), high melting point $(3225^{\circ}C)\;and\;10\%$ IACS electrical conductivity. On this account, the dispersion hardening $Cu-TiB_2$ composites(MMCs) are a promising candidate for applications as electrical contact materials. MMCs for electrical contact materials can reduce material cost and resource consumption caused by wear, due to its good mechanical and electrical property. In this study, we attempt to prepare MMCs with various volume fraction and particle size of $TiB_2$ by means of hot extruded and cold drawn process. Dry sliding wear tests were performed on a pin-on-disk type wear tester, sliding against SM45C under the different applied loads. After wear testing, the microstructures of the worn surfaces were observed by SEM and the microhardnesses of the subsurface zone were measured.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.3-8
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• 1996

To enhance the cutting performance of the tool, single or multilayer coating is applied on the substrate of the tool. Coating material reduces cutting force and heat generation in tool-chip contact zone and enhances resistance against abrasive wear. This paper presents that the effect of different coatings on abrasive wear resistance varies with work material and the flank wear rate is different with depth of cut. Crater wear rate is also found to decrease with higher thermal diffusivity of coating material. It is verified that the estimated thermal diffusivity of multilayer coating has consistent effect on the crater wear.

• Tribology and Lubricants
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• v.9 no.2
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• pp.36-48
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• 1993

This study is concerned with the changes (deterioration) of the mechanical properties of used oil in the gasoline engine. The analysed properties of used oil were friction, antiwear, wear debris, load-carrying ability and the formation of surface film. From this study, it was found that the oil used in engine was deteriorated to increase the wear and fricion and decrease the load-carrying ability as the running distance of oil was increased. Also the main cause of deterioration was related to the formation of the protective film on the contact zone. When the film was composed with rich additives (sulfur), this could properly protect contact zone from the increase of wear and friction. But as oil was deteriorated, it could not form such a film and therefore the protective ability of sliding surface diminished.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.882-885
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• 2000

The machinability of material was evaluated using high speed steel drill on hot-rolled high strength steel. Cutting resistance and tool wear were investigated by drilling experimentation. When the steel-board specimens were drilled in industrial condition, the relationship between average of thrust and cutting resistance was random because of slip of chuck and strain of workpiece. The primary objective of this study is to develop the strategy of analysis that can detect drilling states in industrial condition and such strategy is programmed with visual C++. The developed program can analyze thrust of initial rising zone. The result is obtained that thrust of rising zone is closely related to tool wear in despite of industrial condition.