先进材料制备技术-绪论

1、Processing and Manufacturing of Advanced Materials 先进材料制备科学与技术,王华明、汤海波 北京航空航天大学 材料学院 大型金属构件增材制造国家工程实验室 82317102 82339691 ,PART IIntroduction 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: Mecha

2、nical Functional,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,材料合成、制备与成形（Materials Processing）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

3、工艺新料料,材料制备与成形的内涵,材料制备与成形科学 The Science (Fundamentals) of Materials Processing and Manufacturing 材料制备与成形技术 The Technology of Materials Processing and Manufacturing 材料组织性能/服役性能合成/制备工艺相互关系 Relationship of Materials Design Structure Properties Performance - Processing No Contact of Solidified Metal With

4、 the Mold Wall 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 M

5、aterials Science,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

6、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 loss of laser clad Mo2Ni3Si/NiSi coating under high-temperature sliding wear test conditions,Worn surface of 1Cr18Ni9Ti and laser

7、 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 Science,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

8、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 deformation of the surface layer. The subsequent nitriding kinetics were greatly enhanced, so that the nitr

9、iding 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 nanomaterials in improving traditional processing techniques.,热激活过程Thermal Activation Process,Activatio

10、n Energy (Energy Barrier),Metastable State,Stable State,Vacancy 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/N DG=nUv-T(nDSv+DSc) 空位: 系统自由能增加nUv（ Uv：空位

11、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）

12、！ 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

13、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 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 at

14、trition 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 lower than conventional nitriding temperatures (above 500C). This enhanced pr

15、ocessing method demonstrates the technological significance of nanomaterials in improving traditional processing techniques.,Horse Power 1:Understanding and Intelligent or Creative Utilizations of Fundamentals of Materials Science,16 April 2004, Vol.306, SCIENCE,密排晶体结构中原子的堆垛Atomic Stacking in Close

16、Packed Crystals,One Dimensional Closest Packing: Closest Packed Crystallographic Direction,2. Two Dimensional Closest Packing Closest Packed Crystallographic Planes,密排晶体结构中原子的堆垛Atomic Stacking in Close Packed Crystals,2. Two Dimensional Closest Packing Closest Packed Crystallographic Planes,3. Three

17、-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-CFCC Crystal Structure,B,C,B,Stacking Fault,A B C A B C A B C A B C A B C C A B C A B C A B A B C A C A B C A B C A B C,Sta

18、cking Fault,Twin,堆垛层错与孪晶Stacking Fault and Twins,The Nature of a Twin BoundaryA Perfect Coherent Interface,Growth Twins in Nano-crystalline Metals,Before Twining After Twining,Twin Plane,Twining Direction,Crystal Growth via Twins StepsGrowth 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，能有效阻碍位错运动，可起到与普通晶界相似

19、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 Intelligent or Creative Utilizations of Fundamentals of Materials Science,实例之二对“小平面晶

20、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

21、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 I

22、ntelligent Utilizations of Emerging or New Technologies!,Application of Laser in Materials Processing,LASER MATERIALS PROCESSING,Laser: Light Amplification by Stimulated Emission of Radiation Characteristics of Laser: Nearly Coherent Nearly Monochromatic High Directionality High Energy Density,Appli

23、cations of Lasers in Materials Processing,LASER MATERIALS PROCESSING,Laser Materials Processing,Laser Surface Processing Laser Phase Transformation Hardening; Laser Surface Melting; Laser Surface Alloying; Laser Cladding; Laser Shock Processing; Laser Thin Films Depositions, etc Laser Welding, Laser

24、 Cutting, Laser Forming; Laser Micro-Machining and Nano-Fabrications Laser Ablations 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 MAT

25、ERIALS SURFACE PROCESSING,Surface Engineered Tribological Components (涂层材料与涂层技术),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

26、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 MATERIALS 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

27、 Limits Formation of New Metastable Phases Formation of Quasi-Crystalline and Amorphous 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/