Al-Mg-X (X=Cr, Si)합금의 기계적성질에 미치는 결정립크기와 시효조건의 영향

한창석 ( Chang-suk Han ),이찬우 ( Chan-woo Lee ) 한국열처리공학회 2023 熱處理工學會誌 Vol.36 No.2

In this study, the mechanical properties of the Al-Mg-X (X=Cr, Si) alloy, which clearly showed the influence of the specimen and grain size, were investigated by changing the specimen size extensively. In addition, the effect on the specimen size, grain size and aging condition on the mechanical properties of the grain refining alloy according to the addition of Cr was clarified, and the relationship between these factors was studied. As the specimen size decreased, the yield stress decreased and the fracture elongation increased. This change was evident in alloys with coarse grain sizes. Through FEM analysis, it was confirmed that the plastic deformation was localized in the parallel part of specimen S2. Therefore, when designing a tensile specimen of plate material, the W/L balance should be considered along with the radius of curvature of the shoulder. In the case of under-aged materials of alloys with coarse grain size, the fracture pattern changed from intergranular fracture to transgranular fracture as W/d decreased, and δ increased. This is due to the decrease in the binding force between grains due to the decrease in W. In the specimen with W/d > 40 or more, intergranular fracture occurred, and local elongation did not appear. Under-aged materials of alloys with fine grain size always had transgranular fracture over a wide range of W/d = 70~400. As W/d decreased, δ increased, but the change was not as large as that of alloys with coarse grain sizes. Compared to the under-aged material, the peak-aged material did not show significant dependence on the specimen size of σ_0.2 and δ. (Received February 10, 2023; Revised March 15, 2023; Accepted March 15, 2023)

열 플라즈마 인가 전류변화에 의한 ZrVFe 합금 나노분말의 제조특성에 관한 연구

한창석(Chang-Mik Han),정민희(Min-Hee Jung),김헌창(Heon-Chang Kim) 호서대학교 공업기술연구소 2007 공업기술연구 논문집 Vol.26 No.1

Plasma Display Panel (PDP), among various FPD’s, is considered as the most promising candidate for large area display due to its manufacturing process appropriate for a large displaying area, and a good display quality. The getter which can be continuously absorbed and eliminated the generated impurities gas such as O 2 , H 2 , CO, etc. from MgO, barrier rib and fluorescent substances during operation, should be installed in the PDP cell. As a result of install getter in the cell, we could obtain the extending the life time of the PDP with a good display quality. To manufacture getter possessing excellent absorption efficiency, it was produced particles of nano size. In this research, alloy nano powders are synthesized by transferred thermal plasma process which is a promising method to produce composite nano powders of various metals, and also provides high temperature environment(104 K), extremely fast and intense chemical reactions. In this study, the thermal plasma system was operated in a transferred mode and the raw material was used Zr, V ,Fe (57 : 35.8 : 7.2) alloy of ingot type which made from arc melting method, and the produced particles were analyzed according to changing plasma input current range from 120[A] to 160[A] by SEM, EDS, PSA, XRD, BET, PSA (Particle Size Analyzer) and BET analysis of particles synthesized by changing thermal plasma input current. Average size of particles is from 83.2[nm] to 47.8[nm] smaller, in result, we confirmed difference of approximately 35[nm] in diameter of the synthesized particle according to increasing plasma input current because particles was rapidly condensate from difference in temperature of between plasma column area of a high temperature and surround area of plasma column. Result of BET analysis is in inverse proportion to PSA result which has small value of particle diameter by increasing plasma input current. In case of 120[A], BET surface area of particle is 100.9[m2/g],and surface area of particle in condition of 160[A] is 211.2[m2/g]. Thus, as increasing plasma input current, BET surface area of the synthesized particle is more extend.

김정한 소설어 연구 -민중성의 구현을 중심으로-

한창석 ( Chang Suk Han ) 한민족문화학회 2011 한민족문화연구 Vol.36 No.-

본고는 다음에 대략 네 가지 문제의식을 상정하고 이에 대한 답을 도출하고자 하였다. 첫째, 김정한의 소설어는 왜 창조가 아닌 복원인가? 김정한이 천착한 민중의 삶은 과거에서 현재까지 지속적인 것이었다. 허구나 전망이기 보다 증언이므로 신어나 조어가 아니라 삶의 모습을 복원하고 재현할 기존의 어휘를 소설어로 살려쓰기 위한 노력을 기울인다. 둘째, 김정한의 소설어는 왜 민중어인가? 민중의 삶을 증언하는 것은 민중의 언어로 이루어져야 한다. 아울러, 민중의 삶을 생동감 있게 증언하기 위해서는 추상어가 아닌 감각어, 생활어, 고유어로 이루어져야 한다. 셋째, 김정한의 소설어는 어떤 방식으로 작가의식의 구현에 기여하는가? ① 민중의 조락상(凋落相)의 증언; 빈궁어의 전경화 ② 민중어의 갈래; 속담과 관용어/한자성어/고유어/감각어/종교어 ③ 민중과 반(反)민중의 이분법; 구체성과 연대성 넷째, 민중과 반(反)민중의 대립구도는 어떻게 규정되는가? 민중을 수탈하고 질곡으로 몰아넣는 계급(일제, 친일파, 지주, 부패승려, 권력층)은 반민중성을 지닌다. 그런데 김정한 소설에는 반(反)민중의 역할을 수행하는 인물군의 경우에도 계급적으로는 민중의 일원인 경우가 나타난다. 따라서 반민중적 인물은 지위나 신분이 아닌 역할에 따라 판별해야 할 것이다. This manuscript is about to come up the following four kinds of the consciousness of question and obtain the answer for that. 1. What Kim chung han`s novel language is called not creation but restoration for? The populace life that Kim chung han has scrutinized is continuous up to the present time from the past. As it is a testimony to a fabrication or a prospect. The existing language reappearing and restoring their original looks rather than the need for new vocabulary to be selected as the novel language. 2. Why is Kim chung han`s novel language called as the populace language? Testifying the populace language. In addition, to testify the populace life actively. It has to be established not as an abstract language but a sensual language, a living language and their own language. 3.What`s split for language inquire into Kim chung han`s writer`s consciousness? This manuscript describe it separately as follows ① The testimony of a populace`s withering situation: The aspect of poor language. ② The restoration of a populace`s language: a proverb and idiom/idiom/chinese proverb/a existing language/a sensual language/religion language. ③ The bisect method between the populace and anti- the populace: the confrontation expression on a person and the situation. 4. Can the composition of confrontation between the populace and anti-the populace be shown effectively or pertinently? the concept language of the anti-the populace should be careful to adapt generally in the range and the standard of using, because in case of the persons performing the role of the anti-populace in work, the birth might be belonged to the members of the populace. accordingly, It is reasonable to get through the composition of confrontation with the bisect method of the populace under the key point of the role of an exploiter and a person deprived.

비정질상인 Ti₅Si₃ MA분말의 가압소결 동안 소결체의 치밀화 촉진현상 요인에 대한 조사

한창석,진성윤,권혁구,Han, Chang-Suk,Jin, Sung-Yooun,Kwon, Hyuk-Ku 한국재료학회 2020 한국재료학회지 Vol.30 No.6

In this study, factors considered to be causes of promotion of densification of sintered pellets identified during phase change are reviewed. As a result, conclusions shown below are obtained for each factor. In order for MA powder to soften, a temperature of 1,000 K or higher is required. In order to confirm the temporary increase in density throughout the sintered pellet, the temperature rise due to heat during phase change was found not to have a significant effect. While examining the thermal expansion using the compressed powder, which stopped densification at a temperature below the MA powder itself, and the phase change temperature, no shrinkage phenomenon contributing to the promotion of densification is observed. The two types of powder made of Ti-silicide through heat treatment are densified only in the high temperature region of 1,000 K or more; it can be estimated that this is the effect of fine grain superplasticity. In the densification of the amorphous powder, the dependence of sintering pressure and the rate of temperature increase are shown. It is thought that the specific densification behavior identified during the phase change of the Ti-37.5 mol.%Si composition MA powder reviewed in this study is the result of the acceleration of the powder deformation by the phase change from non-equilibrium phase to equilibrium phase.

만성 정신분열증 환자에서 Paroxetine과 Haloperidol 병합투여시 정신병리증상과 Haloperidol, Reduced Haloperidol 혈중농도의 변화

한창수,이민수,김표한,Han, Chang Su,Lee, Min Soo,Kim, Pyo Han 대한생물정신의학회 1996 생물정신의학 Vol.3 No.2

Selective serotonin reuptake inhibitors(SSRIs), as haloperidol, ore metabolized in the cytochrome P450IID6. They can cause inhibition of metabolism of antipsychotics to elevate the serum level of antipsychotics and exacerbate the extrapyramidal symptoms when co-administered with antipsychotics. Among these SSRIs, there ore a few studies about paroxetine compared to fluoxetine or sertraline. In this study, we have intended to know the drug interaction of paroxetine and haloperidol when co-administered two drugs for the chronic schizophrenics by assessing the changes of positive, negative symptoms and extrapyramidal symptoms. for this purpose, we selected 29 subjects, the chronic schizophrenics with no physical problems. They were under maintenance therapy of haloperidol. They ore randomly assigned to placebo group(n=12) and drug group(n=17) by using double blind method. And then, placebo or paroxetine 20mg were administered to the subjects of each groups during 8 week period. We have assessed their psychopathology and extrapyramidal symptoms using Positive and Negative Syndrome Scale(PANSS), Hamilton Rating Scale lor Depression(HRSD), Simpson-Angus Scale at 0, 2, 4, 6, 8 weeks and serum haloperidol, reduced haloperidol levels at 0, 4, 8 weeks during the period. The results ore analysed by using repeated measure MANOVA. 27 subjects have completed the study during 8 weeks. among the subjects, 1) PANSS, HRSD ; no significant difference between groups. 2) Simpson-Angus Scale ; no significant change according to the time and no significant difference between the groups(no group and time effect). 3) Haloperidol and reduced haloperidol level ; no significant change. When co-administered paroxetine and haloperidol, there ore no significant changes of the psychopothology and no significant changes of the extrapyramidal symptoms. In this result, paroxetine seems to be not to affect the metabolism of haloperidol.

금융경쟁력 결정요인에 대한 실증연구

한창호 ( Chang Ho Han ),강임호 ( Im Ho Kang ) 한국국제경제학회 2007 국제경제연구 Vol.13 No.3

웨더스트립의 재료에 따른 특성예측

한창용(Chang Yong Han),장왕진(Wang Jin Jang),이성범(Seong Beom Lee) 한국자동차공학회 2008 한국자동차공학회 지부 학술대회 논문집 Vol.2008 No.11

Automotive companies are interested in material development with low weight and recycling. Weather strip is made from TPE or EPDM. The nonlinear material properties of weather strip are important to predict the behaviors of weather strip. This study concerns material property test to achieve the nonlinear material constant and stress-strain curve. The nonlinear material constant of weather strip is used for the nonlinear finite element analysis. The results of finite element analysis is executed to predict the material property for weather strip.

무전해 코발트계 석출막에 미치는 기판의 영향

한창석,천창환,한승오,Han, Chang-Suk,Chun, Chang-Hwan,Han, Seung-Oh 한국재료학회 2009 한국재료학회지 Vol.19 No.6

The deposition behavior and structural and magnetic properties of electroless Co-B and Co-Fe-B deposits, as well as the amorphous ribbon substrates, were investigated. These Co-based alloy deposits exhibited characteristic polycrystalline structures and surface morphology and magnetic properties that were dependent on the type of amorphous substrates. The catalytic activity sequence of the amorphous ribbon electrodes for anodic oxidation of DMAB was estimated from the current density-potential curve in the anodic partial electrolytic bath that did not contain the metal ions. Both the deposition rate and potential in the initial region were obtained in order of the catalytic activity, depending on the alloy compositions of the substrates. The deposition rate linearly varied against the deposition time. The initial deposition potential may have also determined the structural and magnetic properties of the deposit based on the thickness of ${\mu}m$ order. Furthermore, a basic study of the electroless deposition processes on an amorphous ribbon substrate has been carried out in connection with the structural and magnetic properties of the deposits.

ECAP법으로 제작한 미세 결정립을 가진 Al-Mg-Sc 합금의 초소성에 관한 연구

한창석(Chang-Suk Han),심우빈(Woo-Bin Sim) 호서대학교 공업기술연구소 2023 공업기술연구 논문집 Vol.42 No.2

본 논문은 실온에서 동일 채널 각도 프레스 (ECAP : Equal-Channel Angular Pressing) 기술을 사용하여 Al-3%Mg-0.2%Sc 합금의 결정립 미세화에 대하여 설명하였다. 본 ECAP 기술로 0.2 μm인 미세한 결정립 크기를 얻을 수 있었다. 또한 여러 가지 변형률 속도를 적용하여 미세한 결정립을 가진 Al-3%Mg-0.2%Sc 합금에 대하여 인장시험을 진행한 결과를 제시하였다. 1000% 이상의 연신은 673 K의 온도에서 10-2 s-1을 초과하는 높은 변형율에서 나타났다. 투과전자현미경 (TEM) 및 주사이온현미경(SIM)을 이용하여 인장시험 전과 후의 미세조직을 관찰하였다. 본 실험 결과는 냉간 압연된 Al-3%Mg-0.2%Sc 합금 결과와 많은 기계적특성 차이를 나타내었다. ECAP 기술을 사용하여 결정립을 미세화시키면 높은 변형률에서 초 플라스틱을 나타내는 Al합금의 생산에 유용하다는 것을 입증하였다. This paper describes the grain refinement of Al-3%Mg-0.2%Sc alloy using equal-channel angular pressing (ECAP) technique at room temperature. A grain size as small as 0.2 μm was obtained by this technique. This paper also presents the results of tensile tests on Al-3%Mg-0.2%Sc alloy with fine grain size using various strain rates. More than 1000% stretching was found at a high strain rate exceeding 10-2 s-1 at a temperature of 673 K. Transmission electron microscopy (TEM) and scanning ion microscopy (SIM) were used to observe the microstructure before and after tensile testing. The results showed many mechanical property differences from the cold-rolled Al-3%Mg-0.2%Sc alloy. It was demonstrated that grain refinement using the ECAP technique is useful for the production of Al alloys that exhibit super-plasticity at high strain rates.

주기성 부하를 갖는 DC모터 속도제어 시스템의 SMC와 PI제어의 강인성 비교

한창호(Chang-Ho Han),정석권(Seok-Kwon Jeong) 한국동력기계공학회 2018 동력시스템공학회지 Vol.22 No.3