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Byeong-Joo Lee Byeong-Joo Lee POSTECH - MSE Relation with Materials Science.

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Presentation on theme: "Byeong-Joo Lee Byeong-Joo Lee POSTECH - MSE Relation with Materials Science."— Presentation transcript:

1 Byeong-Joo Lee http://cmse.postech.ac.kr Byeong-Joo Lee POSTECH - MSE calphad@postech.ac.kr Relation with Materials Science

2 Byeong-Joo Lee http://cmse.postech.ac.kr 부품소재산업 현황

3 Byeong-Joo Lee http://cmse.postech.ac.kr 부품소재산업 현황

4 Byeong-Joo Lee http://cmse.postech.ac.kr 부품소재산업 현황

5 Byeong-Joo Lee http://cmse.postech.ac.kr 부품소재산업 현황

6 Byeong-Joo Lee http://cmse.postech.ac.kr 대일 부품소재산업 현황

7 Byeong-Joo Lee http://cmse.postech.ac.kr 금속소재산업 현황 국가 기간산업 국가 기간산업 – 국부의 원천 – 자동차, 기계, 조선, 건설, 전자, 레저, 의료 등 강력한 후방 산업

8 Byeong-Joo Lee http://cmse.postech.ac.kr 금속소재산업 현황 백 만불

9 Byeong-Joo Lee http://cmse.postech.ac.kr 금속소재산업 현황 소재분야 대일무역수지 (2006)

10 Byeong-Joo Lee http://cmse.postech.ac.kr

11 Byeong-Joo Lee http://cmse.postech.ac.kr > ===================================================== 이름 / 학위취득년도 / 임용년도 / 소속기관 ===================================================== 신상용 / 2009.02 / 2013 / 울산대학교 원병묵 / 2008.02 / 2013 / 성균관대학교 이한보람 / 2009.08 / 2013 / 인천대학교 홍영준 / 2011.02 / 2013 / 세종대학교 황병철 / 2004.08 / 2013 / 서울과학기술대학교 김정한 / 2005.02 / 2014 / 한밭대학교 이동근 / 2003.08 / 2014 / 순천대학교 이철호 / 2005.08 / 2014 / 고려대학교 유학기 / 2010.08 / 2015 / 아주대학교 이정구 / 2006.02 / 2015 / 울산대학교 성효경 / 2012.08 / 2015 / 경상대학교 ===================================================== 우수인력배출

12 Byeong-Joo Lee http://cmse.postech.ac.kr 대학생 신소재공학 포항공대 신소재공학과 학부생

13 Byeong-Joo Lee http://cmse.postech.ac.kr Prologue (1)Materials Science and Engineering (2) 대학교 2 학년 학생들이 해야 하는 일 (3) 소재 열역학

14 Byeong-Joo Lee http://cmse.postech.ac.kr Materials Science and Engineering What makes a Material Scientist a Genuine Materials Scientist 인문사회학자 vs. Medical Doctor Thinking & Simulation based on Scientific Knowledge

15 Byeong-Joo Lee http://cmse.postech.ac.kr 연구를 어떻게 할 것인가 ? How to DO RESEARCH Materials Science and Engineering

16 Byeong-Joo Lee http://cmse.postech.ac.kr Materials Science and Engineering - What & How-to-Do Structure Evolution Process Condition Materials Property Research Type I : experiments first, then thinking Research Type II: think first, then do experiments

17 Byeong-Joo Lee http://cmse.postech.ac.kr Thinking is important But, thinking without scientific background is nothing ( 空想 ) Materials Science and Engineering

18 Byeong-Joo Lee http://cmse.postech.ac.kr 황농문 1, 고동균 1, 박성일 1, 김도연 1, 현택환 2 1 미세조직연구단, 재료공학부, 서울대학교 2 산화물나노재료연구단, 응용화학부, 서울대학교 Theory of Monosize Distribution of Nanoparticles

19 Byeong-Joo Lee http://cmse.postech.ac.kr General Fabrication of Monodisperse Nanoparticles Hot Surfactant Solution Surfactant Injection of Organometallic Precursor Aging Exhaustive Size Selection T. Hyeon, Chem. Comm. (Feature Article), 2003, 927-934.

20 Byeong-Joo Lee http://cmse.postech.ac.kr Bawendi, J. Am. Chem. Soc. 1993, 115, 8706 Synthesis of Monodisperse Semiconductor Nanospheres through Burst Nucleation & Size Selection Alivisatos, J. Am. Chem. Soc. 1998, 120, 5343 20 nm 5.1 nm CdSe 8.5 nm CdSe MIT UC-Berkeley

21 Byeong-Joo Lee http://cmse.postech.ac.kr Direct Synthesis of Monodisperse Iron Nanoparticles without a Size Selection Process!!! 20 nm 7 nm Fe Nanoparticles 11 nm Fe Nanoparticles 18 nm Fe Nanoparticles T. Hyeon, Chem. Comm. (Feature Article) 2003, 927-934.

22 Byeong-Joo Lee http://cmse.postech.ac.kr

23 Byeong-Joo Lee http://cmse.postech.ac.kr 1 nm 20 nm Monodisperse 3.5 nm Pd nanoparticles Why Monosize Distribution of Nanoparticles?

24 Byeong-Joo Lee http://cmse.postech.ac.kr → 100 nm → 104 nm + 98 Principle of Monosize Distribution When small and large particles grow at the same rate, 1 nm 5 nm → 2 nm → 6 nm +1

25 Byeong-Joo Lee http://cmse.postech.ac.kr 100nm 1000nm Growth simply leads to monodisperse particles. This approach cannot explain the monodisperse nanoparticles of 4 ~ 10 nm.

26 Byeong-Joo Lee http://cmse.postech.ac.kr Diffusion-Controlled Growth 10 nm (b) 100 sec 10 nm (c) 1500 sec 10 nm (a) initial state

27 Byeong-Joo Lee http://cmse.postech.ac.kr Necessary Conditions for Monosize Distribution 1. No Coagulation (Surfactant) 2. No Ostwald Ripening 3. No Nucleation during Growth

28 Byeong-Joo Lee http://cmse.postech.ac.kr Identification of Nucleation and Growth Sources Nucleation Source  Fe(CO) 5 Growth Source  Fe-oleic complex Synthesis of Monodisperse Nanoparticles without Size Section Requires that Growth Source should be different from Nucleation source.

29 Byeong-Joo Lee http://cmse.postech.ac.kr 6nm 7nm 8nm 9nm 10nm 11nm 12nm 13nm 1 nm size control of monodisperse nanoparticles

30 Byeong-Joo Lee http://cmse.postech.ac.kr Computational Materials & Process Design A Success Story Byeong-Joo Lee POSTECH - MSE calphad@postech.ac.kr Computational Materials & Process Design A Success Story Byeong-Joo Lee POSTECH - MSE calphad@postech.ac.kr

31 Byeong-Joo Lee http://cmse.postech.ac.kr Surface Bulk Concentration Surface Concentration Ave. Concentration Surface 3 layers Surface E, J/m 2 (100)1.6%68%25%0.29 (110)1.6%37%16%0.83 (111)1.6%78%27%0.38 E surf of pure Fe = 2.50, 2.35, 2.56 for (100), (110), (111) (100)0.3%66%23%0.68 (110)0.3%35%14%1.14 (111)0.3%74%25%0.78 Surface Energy vs. Surface Segregation Background Background Change of Surface Energy Anisotropy due to Surface Segregation Change of Surface Energy Anisotropy due to Surface Segregation

32 Byeong-Joo Lee http://cmse.postech.ac.kr without impurity Red Yellow 11,000steps (1sec) Phase Field Simulation of Grain Growth Phase Field Simulation of Grain Growth – steel sheet with impurity

33 Byeong-Joo Lee http://cmse.postech.ac.kr Red Yellow 8,000steps (0.75sec)Initial sample assuming that impurity atoms were segregated before the grain growth Phase Field Simulation of Grain Growth Phase Field Simulation of Grain Growth – modified

34 Byeong-Joo Lee http://cmse.postech.ac.kr Experimental Verification Experimental Verification – (100) texture on Steel Sheet

35 Byeong-Joo Lee http://cmse.postech.ac.kr SiH 4 + GeH 4 + H 2 Reactions during the VLS Process

36 Byeong-Joo Lee http://cmse.postech.ac.kr VLS Growth of Nanowires ① ② SiH 4 + GeH 4 + H 2 200 torr 400 o C  Vapor-Liquid  Liquid-Solid

37 Byeong-Joo Lee http://cmse.postech.ac.kr Nanowire Growth

38 Byeong-Joo Lee http://cmse.postech.ac.kr Motivation - in Collaboration with M.-H. Jo, POSTECH

39 Byeong-Joo Lee http://cmse.postech.ac.kr Melting point depression of Nano particles - Capillarity : Thermodynamics

40 Byeong-Joo Lee http://cmse.postech.ac.kr Thermodynamic Calculation Thermodynamic Calculation – Application to Nano Materials

41 Byeong-Joo Lee http://cmse.postech.ac.kr Pure W W + 0.4wt% Ni Vaccum Annealing Surface Transition and Alloying Effect – N.M. Hwang et al., 2000.

42 Byeong-Joo Lee http://cmse.postech.ac.kr Surface Transition and Alloying Effect Pure W W-14at%Ni Pure W W-14at%Ni

43 Byeong-Joo Lee http://cmse.postech.ac.kr Abnormal Grain Growth – A 60 years old unsolved problem

44 Byeong-Joo Lee http://cmse.postech.ac.kr CVD Diamond - N.M. Hwang et al., J. Crystal Growth 162, 55 (1996) Diamond deposited on silicon substrate Soot deposited on the iron substrate

45 Byeong-Joo Lee http://cmse.postech.ac.kr CVD Si - N.M. Hwang et al., J. Crystal Growth 218, 27 (2000)

46 Byeong-Joo Lee http://cmse.postech.ac.kr 연구를 어떻게 할 것인가 ? How to DO RESEARCH

47 Byeong-Joo Lee http://cmse.postech.ac.kr Thinking is important But, thinking without scientific background is nothing ( 空想 )

48 Byeong-Joo Lee http://cmse.postech.ac.kr Phase Diagram for H 2 O

49 Byeong-Joo Lee http://cmse.postech.ac.kr Course Outline (1) 열역학 기본법칙의 이해 및 응용 (2) 단일 및 복합계 상평형 및 상태도의 이해 (3) 주요 반응, 결함, 상변화 현상 열역학적 해석 능력 배양 시험 : 70% 숙제 : 20% 출석 : 10% 1. Introduction to the Thermodynamics of Materials, David R. Gaskell, Taylor & Francis, 3rd Edition,1995. 2. Thermodynamics in Materials Science, Robert T. DeHoff, McGraw-Hill International Editions, 1993.

50 Byeong-Joo Lee http://cmse.postech.ac.kr 이 병 주 포항공과대학교 신소재공학과 calphad@postech.ac.kr

51 Byeong-Joo Lee http://cmse.postech.ac.kr Introduction – Historical Background Maxwell · Newton → Classical Mechanics → Electromagnetism → Quantum Mechanics · Lagrangian · Rationalism · Hamiltonian · Time Reversible · Experimental fact ( 산업혁명 ) → Thermodynamics · Heat → Concept of Temperature · Empirical Rule · PV work → Concept of Pressure · Time irreversible · Thompson → Rumford · Davy · Mayor · Carnot · Joule · Thomson → Kelvin · Clausius · Maxwell · Gibbs

52 Byeong-Joo Lee http://cmse.postech.ac.kr Introduction - J. W. Gibbs ※ Expansion in scope has been made to embrace not only thermal, mechanical and chemical effects, but also the kinetic energy and the complete set of potentials energies: gravitational, electrical, magnetic and body forces, (with the exception of atomic energy). ※ J. Willard Gibbs, 1883 : On the Equilibrium of Heterogeneous Substances

53 Byeong-Joo Lee http://cmse.postech.ac.kr Introduction - Microscopic vs. Macroscopic Point of View · macroscopic : no special assumption on the structure of matter, directly measured · microscopic : assumption on the structure of matter (molecules), unmeasurable. can only be justified by comparing some deduction with that from macroscopic point of view. · quantum mechanics

54 Byeong-Joo Lee http://cmse.postech.ac.kr Introduction - Role of Thermodynamics · Foundation of materials science · Phase Diagrams, Chemical Reactions, Adsorption, Capillarity effects and Electrochemistry, …, etc.

55 Byeong-Joo Lee http://cmse.postech.ac.kr Introduction - Basic Terminology · System / Surrounding (reservoir) · State (Properties: description of state), Change of state (properties) during a process · Measurable and unmeasurable properties : Unmeasurable property 는 다른 측정 가능한 특성치로부터 결정 ⇔ Property 간의 관계식 (EOS) ※ Thermodynamic systems, thermodynamic properties, thermodynamic relationships

56 Byeong-Joo Lee http://cmse.postech.ac.kr Introduction - Terminology for System · Unary / multicomponent · Homogeneous / Heterogeneous · Closed / Open · Non-reacting / reacting · Exchange of energies / No exchange ( ※ Isolated)

57 Byeong-Joo Lee http://cmse.postech.ac.kr Introduction - State Function & Process Variable · Thermodynamics State or State of Thermodynamic Equilibrium Mechanical, Chemical and Thermal Equilibrium Uniform and well defined thermodynamic coordinates No tendency to change with time of thermodynamic coordinates · path independence → · Extensive and Intensive Properties · Process variable (only have meaning for changing systems) · work & heat

58 Byeong-Joo Lee http://cmse.postech.ac.kr Introduction - Equation of State of an ideal gas · Boyle’s law (1660): · Charles’ law (1787): = constant = 1atm×22.414 liters ∕ 273.16 degree-mole = 0.082057 liter-atm/degree-mole ∙ EOS of the ideal gas: PV = RT ▶ unit of Work 1atm = 76 cm of mercury = 76.0×13.595×980.665 = 1.013×10 6 dyne/cm 2 1atm-liter = 1.013 × 10 2 joule

59 Byeong-Joo Lee http://cmse.postech.ac.kr Introduction - Ideal Gas Temperature Scale

60 Byeong-Joo Lee http://cmse.postech.ac.kr Introduction - Ideal Gas Temperature Scale

61 Byeong-Joo Lee http://cmse.postech.ac.kr Introduction - Ideal Gas Temperature Scale

62 Byeong-Joo Lee http://cmse.postech.ac.kr Introduction - Ideal Gas Temperature Scale


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