Ti-Ni-Cu 형상기억합금의 상변태 및 초탄성에 미치는 가공열처리의 영향

이오연,박영구,쳔병선 ( O . Y . Lee,Y . K . Park,B . S . Chun ) 한국열처리공학회 1994 熱處理工學會誌 Vol.7 No.4

Transformation behavior and superelastic behavior of Ti-Ni-Cu alloys with various Cu content has been investigated by means of electrical resistivity measurement, X-ray diffraction, tensile test and transmission electron microscopy. Two types of heat treatment are given to the specimens : i) Solutions treatment. ii) thermo-mechanical treatment. The transformation sequence in solution treated Ti-Ni-Cu Alloys substituted by Cu for Ni up to 5at.% occurs to B2◎B19` and it proceeds in two stages by addition of 10at.%Cu, i. e, B2◎B19◎B19`. Also, it has been found that Ti-30Ni-20Cu alloy transformed in one stage : B2◎B19. The thermo-mechanically treated Ti-47Ni-3Cu alloy transformed in two stages : B2◎rhomboheral phase◎B19`, while transformation sequence in Ti-45Ni-5Cu and Ti-40Ni-l0Cu alloy transformed as same as solution treated specimens. The critical stress for inducing slip deformation in solution treated and thermo-mechanically treated Ti-40Ni-l0Cu alloy is about 90㎫ and 320㎫ respectively.

Diamond 박막 성장에 미치는 Si 표면 영향의 AES에 의한 연구

이철로(C. R. Lee),신용현(Y. H. Shin),임재영(J. Y. Leem),정광화(K. H. Chung),천병선(B. S. Chun) 한국진공학회(ASCT) 1993 Applied Science and Convergence Technology Vol.2 No.2

Si 기판 표면상태 변화와 관련된 핵생성 자유에너지 증가에 따른 다이아몬드 박막성장 거동을 관찰하였다. 표면 연마조건 변화에 따른 3가지 기판(A-Si, B-Si, C-Si) 위에 동일한 성장조건으로 다이아몬드를 성장하였으며, 이때 형상인자와 관련된 자유에너지 관계는 ΔG_(A-Si)<ΔG_(B-Si)<ΔG_(C-Si)이다. AES, SEM, XRD, RHEED에 의해 각각의 박막 A, B, C를 조사한 결과, 핵생성 자유에너지가 가장 적은 A 박막은 (100) (110) 면이 지배적인 고품위 다이아몬드 박막이다. 자유에너지가 A에 비해 다소 적은 B 박막은 (111) 면이 지배적인 8면체 다이아몬드 박막이고, 자유에너지가 가장 적은 C 박막은 흑연이 많이 함유된 구상의 다이아몬드이다. The effect of nucleation free energy related to Si surface states on diamond film growth behavior has been studied. At first, the three kinds of diamond thin films (A, B, C) were deposited on various Si substrates (A-Si, B-Si, C-Si) whose surfaces were polished with 1 ㎛ diamond paste, 6 ㎛ Al₂O₃ powder and 12 ㎛ Al₂O₃ powder respectively. And then, relative nucleation free energy calculated is ΔG_(A-Si)<ΔG_(B-Si)<ΔG_(c-Si) Although there are some difference in grain size, shape and nucleation site, the thin films on A-Si and B-Si were diamond including a small amount of DLC which was confirmed by AES, SEM, XRD and RHEED. Namely, the diamonds of films (B) were not nucleated in scratches but in dents and larger in grain size compare with the film (C) of which diamond were nucleated not only scratches but also dents. And, the sphere diamond which is not general shape was grown on C-Si. After all, the sphere was turned out to be the diamond including much graphite as a result of the AES in situ depth profiling. Consequently, the diamond shape and quality grown on Si were changed from the crystal which the (100) and (110) planes were predominent to the crystal in which (111) plane was predominent, and next to sphere shape diamond including much graphite according as the nucleation free energy increases.

Strain path effects on the microstructure evolution and mechanical properties of Zr702

Cao, W.Q.,Yu, S.H.,Chun, Y.B.,Yoo, Y.C.,Lee, C.M.,Shin, D.H.,Hwang, S.K. Elsevier 2005 Materials science & engineering. properties, micro Vol.395 No.1

<P><B>Abstract</B></P><P>A commercial-purity Zr702 was grain-refined from 20μm to 0.2–0.5μm by equal channel angular pressing. Grain refinement was most evident in the first pass but was insignificant during the subsequent passes. Two microstructural characteristics evolved: a lamellar structure and an equiaxed subgrain structure during the route A pressing and the route B<SUB>C</SUB> pressing, respectively. Due to the rotation of specimen in between passes, two sets of geometrically necessary boundaries were formed during the route B<SUB>C</SUB> pressing. The mechanism of grain refinement during the route A pressing was evolution of high-angle geometrically necessary boundaries from the low-angled ones, while that during the route B<SUB>C</SUB> pressing was decomposition and rearrangement of pre-existing boundaries. The yield stress of severely deformed specimens increased with the reducing grain size according to a Hall–Petch relationship.</P>

Structural and magnetic properties of epitaxial Co₂FeAl films grown on MgO substrates for different growth temperatures

Chun, B.S.,Kim, K.H.,Leibing, N.,Serrano-Guisan, S.,Schumacher, H.W.,Abid, M.,Chu, I.C.,Mryasov, O.N.,Kim, D.K.,Wu, H.C.,Hwang, C.,Kim, Y.K. Elsevier Science 2012 ACTA MATERIALIA Vol.60 No.19

We report the correlation between the crystalline structure, electronic structure and magnetic properties of Co<SUB>2</SUB>FeAl films as a function of growing temperature both experimentally and theoretically. The Co<SUB>2</SUB>FeAl film grown at room temperature is initially in the partially disordered B2 state, but then it gains a much higher ordered structure with increasing growing temperature due to its transition from short-range to long-range crystallographic order by surface diffusion. Electron energy loss spectroscopy measurements reveals that the increase in the I(L3)/I(L2) ratio of Co can be attributed to the enhanced ferromagnetic exchange interaction between neighboring Co atoms and the fact that the Co contribution is more dominant than the Fe contribution. As the growing temperature increases, many more unoccupied 3d states in Co are observed, hence the Gilbert damping constant increases due to a strong spin-orbit interaction. We also present the results of highly accurate quasiparticle self-consistent GW calculations and confirm that Co<SUB>2</SUB>FeAl in an ideal L2<SUB>1</SUB> structure is indeed a half-metal with a well-defined band gap in the minority spin channel.

Microstructural evolution and tensile properties of oxide dispersion strengthened Alloy 617 at elevated temperatures

Chun, Y.B.,Mao, X.,Han, C.H.,Jang, J. Elsevier Sequoia 2017 Materials science & engineering Structural materia Vol.706 No.-

<P><B>Abstract</B></P> <P>This study investigated evolution of the microstructure of oxide dispersion strengthened Alloy 617 with annealing temperature. A mixture of prealloyed Alloy 617 and Y<SUB>2</SUB>O<SUB>3</SUB> powders was mechanically alloyed and consolidated by hot-extrusion at 1100°C. Hot extrusion developed a submicron-sized grain structure with M<SUB>23</SUB>C<SUB>6</SUB> carbides and finely dispersed Al<SUB>2</SUB>O<SUB>3</SUB> and Y<SUB>2</SUB>Ti<SUB>2</SUB>O<SUB>7</SUB> oxides. The fine-grained structure was stable during subsequent annealing at temperatures up to 1250°C. Further increase of annealing temperature to 1300°C resulted in a significantly coarsened grain structure, which was coincident with the abrupt coarsening of oxides. M<SUB>23</SUB>C<SUB>6</SUB> carbides in the as-extruded conditions were transformed to M<SUB>7</SUB>C<SUB>3</SUB> carbides with complex shapes when annealed at 1200°C, and their shapes changed to very coarse hexagonal prisms at 1250°C, which was followed by the formation of eutectic M<SUB>2</SUB>C carbides at grain boundaries at 1300°C. Tensile tests of the as-extruded ODS Alloy 617 showed that the yield strength decreased steeply at a transition temperature of around 600°C, which can be attributed to diffusional creep along the grain boundaries.</P>

해외근로자에 있어서 산업재해 발생 원인

김용완,김병수,김성천,김준연,이채언,전진호,문덕환,배기택 인제대학교 1985 仁濟醫學 Vol.6 No.4

해외근로자 1,250명에 대한 재해원인(미국 표준연구소와 국제노동기구의 분류법에 의함)을 조사 분석하여 산업재해 예방 대책의 기초 자료를 얻고자 한 것이다. In order to obtain basic reference materiols for the estabishment of effective industrial safety programmes in oversea workers, accident causes were investigated among 1,250 injured workers, The data were analized according to the USA Standards Institute and International Labour Organization method. The results were as follows: 1.The most prevailing injuries were fractures, contusions, strains, cuts, lacerations and punctures, which were 72% of the total 1,250 cases of occupational injuries. 2.The parts of body most frequently injured were spines, upper extremities (including fingers), head and lower extremities. 3.The most responsible source of injuries were building construction, transport and power machine equipments. 4.According to the accident type, fall from elevation, over exertion, caught-in, struck-by and fall on same level were most frequently observed which were 70% of the total number of injuries. 5.According to the unsafe acts, carelessness and unsafety information were most frequently observed which were 80% of the total number of injuries. 6.Unsafety acts were mot responsiable causes of injuries, accounting for 49%. The major hazardous conditions in or about causes were approach of hazardous sites handling of hazadous matrials and carelessness of work motion. 7.Practically all oversea workers accident records could produce the causes of accident which fell into the categories. The moat hazadous conditions were unsafety acts and building construction materials were the most responsible sources of injuries. 8.There were close associations between the nature of injuries and injured body parts, the types and of causes injuries, unsafety acts and kinds of work among injured workers.

韓國食品의 비타민 B_12 性物質 含量 (第1報)

李基寧,李根培,李春寧,全鉉五 서울대학교 1958 서울대학교 論文集 Vol.7 No.-

Vitamin B_12 contents of a variety of conventional Korean foods were bioassayed employing Euglena gracilis. On the basis of fresh weight animal organs and fremented sea foods are excellent sources of vitamin B_12. Several foods of plant origin were found to be fair sources of the vitamin B_12.

Evaluation of the chemical composition of brown seaweed (Saccharina japonica) hydrolysate by pressurized hot water extraction

Saravana, P.S.,Choi, J.H.,Park, Y.B.,Woo, H.C.,Chun, B.S. Elsevier B.V 2016 Algal research Vol.13 No.-

<P>In this study, Saccharina japonica was treated with pressurized hot water extraction (PHWE) at a temperature of 180 degrees C-420 degrees C and pressure between 13 bar and 520 bar. The obtained hydrolysate was investigated for their yield, total organic carbon (TOC), pH, Maillard reaction products, viscosity, color, and amino acid, mineral, and monosaccharide contents. The extraction yield increased with an increase in temperature and varied from 72.21% to 98.91%. TOC, pH, and potassium and sodium content increased, whereas viscosity decreased, with an increase in temperature. Essential amino acids such as valine and lysine and non-essential amino acids such as aspartic acid, glutamic acid, glycine, and tyrosine recovered well at low temperature. The content of heavy metals such as arsenic, cadmium, mercury, and lead was very low in the obtained hydrolysate. The maximum amount of total amino acids was recovered at 180 degrees C/13 bar (761.95 +/- 14.54 mg/g). The level of main monosaccharides such as glucose (6.70 g/L), fructose (8.40 g/L), and mannitol (17.50 g/L) was found to be very high at 180 degrees C/13 bar. The results indicated that the pressurized hot water extract of S. japonica has good potential for use in the fermentation industry and can be used as human food. (C) 2015 Elsevier B.V. All rights reserved.</P>

職場人의 肝炎 B바이러스 表面抗原 및 抗體에 關한 疫學的 考察

김용완,김병수,배기택,김준연,이채언,전진호,문덕환,김성천 인제대학교 1985 仁濟醫學 Vol.6 No.4

1984년 1월부터 12월까지 정기 및 채용시 신체 검사를 받고자 본 인제대학 부속 서울 및 부산 백병원 건강관리과를 찾은 남ㆍ녀 근로자 4,153명을 대상으로 혈청 HBsAg, HBsAb를 검출하고 ABO 혈액형, 매독 혈청 검사(TPHA), 간기능 검사(SCOT, SGPT)등과의 관계를 고찰하였다. To investigate the positive rate of the hepatitis B virus surface antigen (HBsAg) and its antibody (HBsAb) in the sera of healthy workers, the authors tested HBsAg and HBsAb by RPHA and PHA method respectively with the sera obtained from 4153 healthy adults (Male 3477, female 676) who were placed under the preemployment and periodic health examination in the department of Health Management of Seoul and Pusan Paik Hospital, Inje Medical College, for one year from January to December, 1984. In addition the authors studied the association of HBV infection with liver function tests (SGOT and SGPT), sero-re-activity for syphilis (TPHA) and ABO blood type. The results obtained were as follows; 1.The (overall) positive rate of HBsAg was 8.0%. This rate was significantly higher in male (8.7%) than in female (4.1%). 2.The (overall) positive rate of HBsAb was 28.6%. This rate was significantly higher in Pusan area (34.3%) than in Seoul area (25.1%). 3.The (overall) positive rate of HBsAg or HBsAb was 36.6%. This rate· was significantly higher in male (37.6%) than in female (31,2%) and in Pusan area (43.2%) than in Seoul area (32.6%). 4.The positive rates of HBsAg and HBsAb were the highest in blood type B (9.4% and 31.3%) and the lowest in blood type A (7.0% and 26.5%) but no significant differences of these positive rates among ABO blood type groups were observed. 5.The positive rate of HBsAg was significantly higher in workers with sero-reactivity for syphilis (20.0%) than in workers without sero-reactivity for syphilis (7.9%). However no significant difference of the positive rate of HBsAg or HBsAb between workers with (40.0%) and without (36.6%) sero-reactivity for syphilis was noted. 6.The Qccupied percentage of workers with HBsAg positive was significantly higher than that of workers with HBsAb positive and HBsAg or HBsAb negative. However, this phenomenon was not observed in groups of SGOT and SGPT levels less than 24 units.

박막자기헤드의 집적공정 기술개발에 관한 연구

이석윤,허명수,손동수,황병철,조동율,천희곤,오태희,송병무,송한식,이우형,이광철,김오규,권영규,구경완 경북대학교 센서기술연구소 1995 센서技術學術大會論文集 Vol.6 No.1

The thin film growing processes and the photolithographic techniques involved in the manufacturing of thin film magnetic heads are discussed. The thin film heads are composed of the hundreds of electromagnetic transducers on a single wafer and are made of Al_(2)O_(3)-TiC substrate on which Al_(2)O_(3) film as a insulating, protective layer and gap material, Cu film as a multi-turn coil and permalloy film as a magnetic material are deposited and patterned. In this article we will introduce how the thin film heads is fabricated and differ from an integrated semiconductor device. An effort is devoted to develop the formation of PR frame using a lithography process and finally the thin film heads manufacturing technologies.