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1-先进材料制备技术-绪论.ppt

1、Processing and Manufacturing of Advanced Materials 先进材料制备科学与技术,王华明 北京航空航天大学 材料学院 激光材料制备与成形实验室 82317102 ,PART I Introduction and Fundamentals of Advanced Materials Processing and Manufacturing 第一部分 先进材料制备科学与技术基础,The Four Elements of MSE,Processing/Synthesis,Structure,Properties: Mechanical Functional

2、,Performance,制备成形/合成,结构(成分),性能,服役性能(性能/价格比),The Role of Materials Processing in MSE,净重438吨的三峡电站不锈钢水轮机叶轮铸件 (制备与成形:合金冶炼铸造热处理焊接),三峡电站大型水轮机不锈钢叶轮 (从加拿大进口:价格950万美元/个),大型核电部件的热处理,百万千瓦超超临界汽轮机低压转子大型构件淬火,材料制备与成形 Materials Processing and Manufacturing 在MSE中的地位和作用 核心支柱,基本手段和方法合成制备新材料发现新材料提高现有材料性能零件成形制造 材料制备新工艺新

3、料料,材料制备与成形的内涵,材料制备与成形科学 Science (Fundamentals) of Materials Processing and Manufacturing 材料制备与成形技术 Technologies of Materials Processing and Manufacturing 制备工艺材料组织性能/服役性能间相互关系 Relationship of Materials Processing & Manufacturing Structure Properties & Performance 过程控制及自动化 Process Control and Automati

4、on of Materials Processing,All Processes and Procedures which, through intelligent utilizations of Fundamentals of MSE and related disciplines, and various existing or new technologies or special environments, etc Synthesize or fabricate materials, Change or Control the internal structures (macro -o

5、r microstructure, atomic arrangements, etc ) for Designed or Tailored mechanical or functional properties of materials, Form, shape and manufacture materials and components while changing materials internal structures or properties, etc,What Is Materials Processing?,Some Representative Examples of M

6、aterials Processing Methods Solidification Processing (Melting, Casting, Welding) Thermal Processing (Heat Treating, Sintering, etc) Mechanical Processing (Cold forming & rolling, etc ) Thermal Mechanical Processing Electro-magnetic Materials Processing Biological Materials Processing High Energy De

7、nsity Beam Materials Processing, Surface Materials Processing Vacuum Materials Processing, Space or Micro-gravity Materials Processing,etc.,Driving Force Social and Military Requirements for Better Materials(需求牵引!) Personal Interests and Curiosity for Novel Materials etc Horse Power Understanding an

8、d Intelligent Utilization of Fundamentals of Materials Science Innovation or Improvement of Current Materials Processing Technologies Intelligent Utilization of New or Innovative Technologies etc,Horse Power 1: Understanding and Intelligent or Creative Utilizations of Fundamentals of Materials and R

9、elated Disciplines,Example 1. Preferred Orientation of Crystal Growth and the Unidirectional Solidification Processing Technology,Preferred Orientation and Competition in Crystal Growth DS Columnar Grain and Single-Crystal Turbine Blades,定向凝固单晶镍基高温合金涡轮叶片,定向凝固单晶镍基高温合金涡轮叶片,Horse Power 1: Understanding

10、 and Intelligent or Creative Utilizations of Fundamentals of Materials and Related Disciplines,Example 2: Theoretical Study on Nucleation Mechanisms of Equiaxed Grains of Metal Casting and Development of OCC Process,Separation of Crystals from Mold Walls Crystal Shower from Top Melt Free Surface Fra

11、gments of Dendrite Arms due to Melt Convection Endogenous Nucleation due to Constitutional Undercooling, .,Cooling Water Spray,Heated Mold,Ohno Continuous Casting (OCC) Process Mold Temperature Higher Than the Alloy Liquidus No Nucleation on Mold Wall; No Contact of Solidified Metal With the Mold Wa

12、ll Very Smooth Surface; Solidification Starts from Interior No Central Shrinkage and Segregation Fully Directionally Solidified or Single-Crystal Wires, Bares, Shaped Parts or Multi-Metal Materials.,Horse Power 1: Understanding and Intelligent or Creative Utilizations of Fundamentals of Materials an

13、d Related Disciplines,Example 3: Atom Structure and Basic Properties of TCP Phases and Development of Wear, Corrosion Resistant Metal Silicide Alloys,拓朴密堆相 Topologically Close-Packed (TCP ) Phases,CN 12 (14, 15, 16) 间隙全部为四面体间隙 无八面体间隙 原子间结合力很强共价键 高硬度、高耐磨、高耐蚀等,TCP相的结构及TCP相金属间化合物耐磨合金涂层新材料:,1.高硬度:优异的磨料磨

14、损及粘着磨损性能2. 原子间结合力强、共价键与金属键共存,难于发生金属粘着、粘着磨损性能 极好、摩擦系数很低、摩擦学相容性高温组织稳定性与性能稳定性优异,3. 金属键仍占相当比例 保证涂层/金属基材间可实现冶金结合4. 存在广阔的合金化与多相平衡空间可灵活地进行合金化,对组织、性能与制备工艺进行灵活设计与控制!,Hexagonal MgZn2 Type (hP12) Laves Phase,MgZn2中A、B原子的分布和双原子堆垛方式,Laser Clad Mo2Ni3Si/NiSi IMC Coating Dry Sliding Wear Resistance,(),Wear mass lo

15、ss of laser clad Mo2Ni3Si/NiSi coating under high-temperature sliding wear test conditions,Worn surface of 1Cr18Ni9Ti and laser clad Mo2Ni3Si/NiSi coating after sliding wear tests at 600 for 60 min,Horse Power 1: Understanding and Intelligent or Creative Utilizations of Fundamentals of Materials and

16、 Related Disciplines,Example 4: Nano-Structured Surface Mechanical Processing and Low Temperature Nitriding of Iron,Nitriding Iron at Lower Temperatures W. P. Tong, N. R. Tao, Z. B. Wang, J. Lu, K. Lu* Science 299 (2003)5607, 686-688.,2003年中国十大科技新闻(位列第二) Microstructure in the surface layer of a pure

17、 iron plate was refined at the nanometer scale by a surface mechanical attrition treatment that generates repetitive severe plastic deformation of the surface layer. The subsequent nitriding kinetics were greatly enhanced, so that the nitriding temperature could be as low as 300C, which is much lowe

18、r than conventional nitriding temperatures (above 500C). This enhanced processing method demonstrates the technological significance of nanomaterials in improving traditional processing techniques.,热激活过程 Thermal Activation Process,Activation Energy (Energy Barrier),Metastable State,Stable State,Vaca

19、ncy Mechanism: Diffusion of Substitutional Solute Atoms 空位机制:置换式溶质原子 (置换式原子的扩散就是空位的反向运动),位错、层错、晶界、相界、表面,面缺陷(晶界、相界、表面): 溶质原子扩散的快速通道,晶内、晶界及表面扩散系数,一、空位 Vacancies 一种热力学稳定的晶体缺陷,晶体热力学:N个晶格结点、n个空位,空位浓度Cv=n/NDG=nUv-T(nDSv+DSc) 空位: 系统自由能增加nUv( Uv:空位形成自由能)空位: 组态熵DSc及振动熵DSv增加系统自由能降低,空位对合金组织及性能控制的重要性,物理及电子学性质(密

20、度、电学、电子学性能) 原子扩散的基本(最重要)方式对合金固态相变过程(形核、长大;时效)及固态相变组织具有决定性影响;对合金扩散控制的热加工工艺(如渗金属、烧结等)组织具有决定性影响;对合金力学性能特别是高温力学性能具有决定性影响(强度、塑性、耐蚀、氧化),获得非平衡空位(过饱和空位)的方法,高温淬火(Quenching):通过极端手段把高温下的平衡空位快速“冷冻”固定到室温快速凝固;固溶处理:过饱和固溶体(固溶强化)、过饱和空位(固溶后时效热处理工艺要求的原因)! 强烈塑性变形:表面喷丸强化表面纳米化 高能粒子辐照:中子辐照等(同时产生自间隙原子),材料性能严重脆化!,2003年中国十大科

21、技新闻之一对纯铁进行表面纳米化处理,在几十微米厚的表面层中获得纳米晶组织。然后利用常规气体氮化处理在300 oC保温9小时后成功地实现了表面氮化,获得10微米厚的氮化物层,而未经处理的纯铁在同样条件下几乎无氮化物形成。性能测试结果表明在300 oC下形成的表面氮化层具有很高的硬度、耐磨性和耐腐蚀性。这一结果证明铁的表面氮化温度可以利用表面纳米化技术而大幅度下降,从而使表面氮化技术的适用面(材料和工件种类)大大拓宽。同时也说明通过表面纳米化技术可以实现材料表 面结构选择性化学反应。这一成果再次显示纳米技术对传统产业技术的升级改造具有重要的推动作用。,Nitriding Iron at Lower

22、 Temperatures W. P. Tong, N. R. Tao, Z. B. Wang, J. Lu, K. Lu* Science 299 (2003)5607, 686-688.,2003年中国十大科技新闻(位列第二) Microstructure in the surface layer of a pure iron plate was refined at the nanometer scale by a surface mechanical attrition treatment that generates repetitive severe plastic deforma

23、tion of the surface layer. The subsequent nitriding kinetics were greatly enhanced, so that the nitriding temperature could be as low as 300C, which is much lower than conventional nitriding temperatures (above 500C). This enhanced processing method demonstrates the technological significance of nan

24、omaterials in improving traditional processing techniques.,Horse Power 1: Understanding and Intelligent or Creative Utilizations of Fundamentals of Materials and Related Disciplines,Example 5: Atomic Arrangements of Twins and Development of Superhigh Strength High Electrical Conductive Nano-Twined C

25、opper,16 April 2004, Vol.306, SCIENCE,密排晶体结构中原子的堆垛 Atomic Stacking in Close Packed Crystals,One Dimensional Closest Packing:Closest Packed Crystallographic Direction,2. Two Dimensional Closest PackingClosest Packed Crystallographic Planes,密排晶体结构中原子的堆垛 Atomic Stacking in Close Packed Crystals,2. Two

26、Dimensional Closest PackingClosest Packed Crystallographic Planes,3. Three-Dimensional Closest Stacking of Closest Packed Atomic Planes,Stacking Sites Stacking Sequence,Stacking Sequence: A-B-A-B- HCP Crystal Structure,A,B,Stacking Sequence: A-B-C-A-B-C FCC Crystal Structure,B,C,B,Stacking Fault,A B

27、 C A B C A B C A B C A B CC A B C A B C A B A B C A C A B C A B C A B C,Stacking Fault,Twin,堆垛层错与孪晶 Stacking Fault and Twins,The Nature of a Twin Boundary A Perfect Coherent Interface,Growth Twins in Nano-crystalline Metals,Before Twining After Twining,Twin Plane,Twining Direction,Crystal Growth via

28、 Twins Steps Growth Twins,纳米生长孪晶强化超高强度和高导电性铜,孪晶界是一种低能共格界面,能有效阻位错运动,可起到与普通晶界相似的强化作用。 共格孪晶界对电子的散射能力极小,其电阻值比普通晶界的电阻低一个数量级。引入大量孪晶界(即制备出高密度纳米尺寸生长孪晶)可以大幅度提高材料的强度而对其电导特性无明显影响,Strong Blockage of a Twin Interface to Dislocation Movement,16 April 2004, Vol.306, SCIENCE,Horse Power 1: Understanding and Intelli

29、gent or Creative Utilizations of Fundamentals of Materials and Related Disciplines,Example 6 Atomic Arrangements of Twins and Development of Superhigh Strength High Electrical Conductive Nano-Twined Copper,实例之6 对“小平面晶体液固界面结构与生长机制转化”经典凝固理论 的再认识 (讲授本科生课程金属学原理的“收获”之一) (很长时间的积累、很久的思考),小平面晶体著名的凝固理论,有关小面晶

30、体经典凝固理论 “随凝固冷却速度增加,液/固界面结构将由原子尺度光滑向原子尺度粗糙转变、生长机制由侧向生长向连续生长机制转变”的经典凝固理论“著名推论” ,迄今只在Si等非典型小面晶体中得到实验证实。对 “高Jackson因子小面晶体”是否具有普遍适用性,一直缺乏实验及理论依据。,101105 K/s范围内,发现TiC经典小面晶体生长新形态及演化规律,发现“原子尺度光滑的液/固界面及其台阶侧向生长机制”基本特征均不随凝固冷却速度的改变而变化!,(a),(b),光滑界面 粗糙界面?,当DT DTc时,,DTc,侧向生长连续生长?,经典小面晶体凝固理论有关“随凝固冷却速度增加,液/固界面结构由光滑

31、向粗糙转变、生长机制由侧向生长向连续生长转变”的著名推论,对高Jackson因子小面晶体不具普遍意义!,SCI研究论文收录10余篇 陈瑶获全国百篇优秀博士论文提名奖,Horse Power 2: Improvements and Innovations of Current Materials Processing Technologies or Processes,Horse Power 3: Acute Perception and Intelligent Utilizations of Emerging or New Technologies!,Application of Laser

32、in Materials Processing,LASER MATERIALS PROCESSING,Laser: Light Amplification by Stimulated Emission of RadiationCharacteristics of Laser: Nearly Coherent Nearly Monochromatic High Directionality High Energy Density,Applications of Lasers in Materials Processing,LASER MATERIALS PROCESSING,Laser Mate

33、rials Processing,Laser Surface ProcessingLaser Phase Transformation Hardening; Laser Surface Melting; Laser Surface Alloying; Laser Cladding; Laser Shock Processing; Laser Thin Films Depositions, etc Laser Welding, Laser Cutting, Laser Forming; Laser Micro-Machining and Nano-Fabrications Laser Ablat

34、ions for Thin Films Deposition Laser Rapid Manufacturing of High-Performance Metallic Components.,LASER and LASER MATERIALS PROCESSING “激光材料制备、加工与成形制造科学与技术” 新兴交叉学科,加热/冷却;固态相变;熔化/凝固;蒸发沉积;消融;消融沉积;冲击波;光、热化学反应与核反应等,LASER MATERIALS SURFACE PROCESSING,Surface Engineered Tribological Components (涂层材料与涂层技术)

35、,材,复,料,合,材料A,材料 B,力学性能:强韧性,表面性能,表面工程: 零件性能最优化,表面涂层,零件本体,Solid-State LASER MATERIALS PROCESSING Transformation Hardening Laser Shock Processing Laser Bending (forming),激光表面淬火 Laser Surface Hardening 金属零件及模具表面强化方法之一,主要作用 表面硬度 耐磨性与寿命 疲劳、接触疲劳与热疲劳寿命 .,例:汽车弹簧及齿轮激光淬火表面强化,Rapid Solidification LASER MATERIAL

36、S PROCESSING,Effects of Rapid Solidification Processing on Structure of Metallic Materials,Refinement of Grain Size and Microstructure (PDAS, SDAS, Eutectic Colony Size and Spacing, Porosity, etc) Extension of Solubility Limits Formation of New Metastable Phases Formation of Quasi-Crystalline and Am

37、orphous Phases (Metallic Glass) Suppression of Solidification Segregation,激光表面熔化/快速凝固Rapid Solidification Laser Surface Processing,主要作用 耐磨性 耐蚀性 耐氧化性 疲劳热疲劳 其它表面性能.,例:大型拉丝模具激光表面熔化强化: 使用寿命由12天提高到1年半以上,激光表面合金化 Laser Surface Alloying,主要作用 耐磨性 耐蚀性 耐氧化性 疲劳热疲劳 其它表面性能.,例:钛合金零件激光表面合金化,制备Ti5Si3/Ti高耐磨表面合金层,耐磨性提

38、高100余倍!,Ti5Si3,Ti5Si3/Ti Composite Coatings High Quality Metallurguical Bonding,Ti5Si3/b-Ti,Ti-6Al-4V,例:钛合金零件激光表面合金化,制备Ti5Si3/Ti高耐磨表面合金层,耐磨性提高100余倍!,Melt Pool,LASER CLADDING: an Advanced Surface Technology Synthesis of Advanced Coating Materials Fabrication of High-Quality Metallurgical Coatings,基材涂

39、层梯度过渡区,W/W5Si3 Refractory Metal Silicides Matrix in-situ Composites (W/ W5Si3),W,W5Si3,LASER ADDITIVE MANUFACTURING,主要内容,先进材料制备科学与技术概论 先进材料凝固制备成形科学与技术 先进金属基复合材料制备科学与技术 先进材料激光制备、加工与成形科学与技术 纳米材料制备科学与技术 先进材料制备加工新技术进展评述,课程目的,了解先进材料制备的科学基础与先进材料制备技术的基本原理, 认识材料科学“材料加工制备工艺-材料组织结构-材料性能”三要素中“材料加工制备技术的突出作用及“新工艺”与“新材料”的关系, 熟悉通过材料先进制备技术发展高性能新材料的基本思路。,授课形式及目标,授课形式:专题讲座以点带面(无教材) 课程目标:研究思路研究方法创新启示,考核方式,笔试 课程报告,XX材料及其制备技术研究进展评述 必须有自己的评述,不少于8000汉字,至少包括以下内容:,前言(背景、原理、主要问题等) 国内外研究进展及评述 结论 参考文献,先进材料制备科学与技术课程报告题目及要求,

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