Influence of Phase Composition in TiAlSiN Hard Coatings on the Evolution of Structure and Mechanical Properties

Jeong‑Han Lee,Ik‑Hyun Oh,Jun‑Ho Jang,Ju‑Hun Kim,Sung‑Kil Hong,Hyun‑Kuk Park 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.3

The aim of this study is to investigate the structural evolution and mechanical properties of TiAlSiN coatings when processedby the arc ion plating method. To form a hard coating, Ti, Al, and Si powders were mechanically alloyed by planetary ballmilling; the powders were then densely compacted during a rapid sintering process into a ternary system coating, i.e. TiAlSi. The evolution of the structural phase from a powder to a compact material is dominated considerably by phase states suchas a supersaturated solid solution or intermetallic compounds. In the case of coating layers, the factors that determine thestructural evolution are associated with the phase stability of the nano-crystalline structure that in turn is associated withthe Ti/Al composition ratio. Motivated by this, we performed experiments to investigate the distribution of microstructures;the material’s binding energy, quantitative properties, transformation of crystal structure, and distribution of amorphous/crystalline were all recorded. In particular, the relationship between the physical and chemical properties during the coatingprocess is considered to be the dominant factor controlling the orientation and morphology of that zone (1, T, and 2). TheTiAlSiN coating layer was found to have hardness above 45 GPa and an adhesion above 100 N. In other words, understandingthe evolution and structure of TiAlSin helped us to produce a material with excellent properties that can be used as a hardcoating. Specifically, these properties were induced by a grain refinement of the nano-crystalline structure that correspondsto an increase in the silicon nitride contents.

Effect of Mechanical Alloying on the Microstructural Evolution of Al60Cr30Si10 Alloys Processed by Spark Plasma Sintering

Jeong‑Han Lee,Ik‑Hyun Oh,Jun‑Ho Jang,Ju‑Hun Kim,Sung‑Kil Hong,Hyun‑Kuk Park 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

In this study, Al, Cr and Si fine powders were alloyed by planetary ball milling to investigate their microstructural evolution,following their mechanical alloying behavior. The formation of Al(Cr) supersaturated solid solution by the Cr grainsembedded in Al-matrix, which contributed substitutional structure is discussed in relation to their structural evolution inaccordance with the distortion of a crystal lattice. The compacts of Al–Cr–Si alloys were prepared by rapid sintering withina short time by dense consolidation above the density of 99.9% as the formation of intermetallics, except in the case of thedistribution of single-phases induced by the Al-melting. The formation behavior of intermetallics was dominated by dependenceon the structures of the milled-powder and subsequent sintering temperature. To estimate the consolidated behaviorsof compacts, various approaches derived from TEM and XRD analysis were taken to obtain microstructural evidences ofthe inter-diffusion, following the presence of thermally stable intermetallics.

복합 운동프로그램이 초등학생의 신체구성, 혈중지질 및 체력에 미치는 영향

전종귀,이왕록,박희근,정준현,이영란,신동원,이경숙 충남대학교 체육과학연구소 2006 體育科學硏究誌 Vol.23 No.1

The purpose of the present study was to examine the effects of combined training on the changes of body composition, blood lipid profile and fitness in elementary school students. Thirty subjects participated in the present study. The subjects were divided into two groups either exercise group for 10weeks(15n) or control group for 10weeks(l5n) The results were described as follows; 1) There were significant differences in the body weight and lean body mass after the exercise program between two groups. 2) There were no significant differences in the blood TC, HDL-C, LDL-C, TG concentration after the exercise program between two groups. 3) There were significant differences in the sit-up and flexibility after the exercise group between two groups. In conclusion, it might be thought that the combined training improved the levels of body composition and health-related fitness in elementary subjects.

전통마을 주거환경 및 주거공간의 구성적 특성에 관한 연구

정준현,백영흠 대구대학교 과학기술연구소 1999 科學技術硏究 Vol.5 No.5

This study aims primarily that the charateristics of the organization of the residential environment in the traditional village, and the regional type of the traditional residence(Min Ga) is surveyed and analyzed to be objected on the Mun-Keyng, Bugok Ma-ul. By The first visit for the site on July, 1997 to be established the surveying plan, the main surveying is duing 20∼25 on August,1997, and the additional surveying is duing during May and June, 1998.

구미4공단지정 지역의 주거환경 및 민가의 공간구성적 특성에 관한 연구

정준현,백영흠 大邱大學校 科學技術硏究所 1999 科學技術硏究 Vol.5 No.5

The study aims that research the characteristic of housing environment on 4 villages in the reserved area for Kumi national industrial park. Especially theses villages based on traditional agricultural economic living, will be changed to the industrial park, and so it need to record the village history and the distribution of existing house buildings and also to preserve the heritages of tangible & intangible culture. Thus the study bases on the housing environment for a history and living of housing. The contents of study is limited to declare the characteristics of the spatial plan of villages and the traditional house's typology. By the application of the space syntax analytic method, to four villages and it's houses, the actual surveying and interviewing and questioning were proceeded as the primary and main surveying on 8, 1997 and the supplementary surveying on 25-28, 8, 1998.

내곡마을의 空間構成 및 住居建築의 特性에 관한 硏究

정준현,백영흠 大邱大學校 科學技術硏究所 1998 科學技術硏究 Vol.5 No.3

This study aims to identity and analy the charateristics of organization of the residential enviornment in the Hap-Chun, Naegok Ma-ul, which is of the representative traditional village. The survey were conducted from July 25 to 30 in 1997 to investigate the charateristics of the village To have additional information, second survey uwre carried out during May and June, 1998.

아파트 외부환경에 대한 감성평가 사례연구

정준현 대구대학교 디자인연구소 2002 디자인연구논집 Vol.1 No.1

The purpose of this study is to introduce emotional evaluation model of apartments' exterior environment in order to qualitatively improve residental environment and comfortableness of apartments. Two apartment housing estates recently built in the Daegu and one in the Kwangju area were selected for the purpose of this study. In this study, theevaluation group consisting of residents(housewife), 30 undergraduates and 30 students of architectural major field evaluated the extent of emotion by physical elements of the subject apartments on the basis of 30 SD emotional tranquility scales of each group. For this experiment, photographs were taken on March 23, 2000, and the evaluation of the extent of emotion was made on June 21, 2000. Effective statistical result values were drawn by analysing the data obtained, using the SPSSWIN statistical program.

성견 치은에서 90% Phenol을 이용한 멜라닌 색소의 제거에 관한 연구

정태술,김영준,이영규,정현주 전남대학교 치의학연구소 2001 구강과학 Vol.13 No.4

In this present study, the healing process and the recurrence of pigmentation were evaluated clinically and histologically in accordance with the extent and the range of pigmentation after phenol was applied to remove melanin pigmentation in gingiva. Six mongrel dogs were used. The melanin pigmentation in canine gingiva were classified into slight, moderate, and severe according to the extent of pigmentation and divided into local and diffuse types according to the range. Following general and local anesthesia, 90% phenol was applied to the pigmented gingiva of the subjects with small cotton balls until the surface was etched to be whitish and was neutralized with small cotton balls soaked by 95% alcohol. The contralateral pigmented gingiva to the one treated with phenol, was treated by surgical deepithelialization. At1, 3, and 8 weeks, the treated gingiva was examined clinically and evaluated histologically following H-E stain, and HMB 45 stain for melanocyte after biopsy. In the phenol treated sites, epithelium and connective tissue healed normally and there was no pigmentation at 1 week. At 3 weeks of healing, melanin repigmentation was observed in the severe local type and moderate to severe diffuse type. In the surgically deepithelialized sites, healing was delayed, compared to phenol treated sites and the infiltration of the inflammatory cells and congestion in connective tissue was shown at 1 week. At 3 weeks, healing was completed and there was a partial melanin repigmentation. At 8 weeks of healing, the extent and the range of repigmentation were increased in both group according to the extent or range priot to depigmentation procedure. These results suggest that the removal of melanin pigmentation with 90% phenol application result in normal healing process of gingiva. However, in the severe local type and moderate to severe diffuse type, sites treated with phenol showed repigmentation at 3 week, which was earlier than surgical deepithelialized sites. Therefore it is required to select appropriate method according to initial condition of pigmentation.

Expansin으로 형질전환 된 담배의 생장 특성

신하정, 성현정, 백승준, 김보미, 엄유리, 조은정, 정찬문, 이이 충북대학교 연초연구소 2008 煙草硏究 Vol.21 No.-

-본문참고-

실비우스 수도를 경유한 뇌낭미충 낭종의 이주 -증례 보고-

김정훈,송준혁,김명현,박향권,김성학,신규만,박동빈 대한신경외과학회 1999 Journal of Korean neurosurgical society Vol.28 No.4