2.1材料概论-陶瓷双语选编

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,Chapter 3 Ceramics,陶瓷材料,龙志强,重庆理工大学,材料科学与工程学院,材料概论,Introduction to Materials,2,Inorganic Non-metallic Materials,陶瓷材料的概念与分类,Concept and classification,陶瓷的结构,Structure of Ceramics,陶瓷材料的制作工艺,Manufacture and processing technologies,陶瓷材料的性能及应用,Properties and applications,1,陶瓷的概念和分类,Concept and Classifications,1.1,概念,Concept,陶瓷,Ceramic,:,烧过的粘土。是陶器,(,pottery,),和瓷器,(porcelain),的总称。,定义,:,陶瓷指经过高温处理所合成的无,机非金属材料,(,Inorganic,&,nonmetallic,materials,),简称无机材料,。,3.1 Introduction,What is the ceramic,The word “ceramic” can be traced back to Greek term “,keramos,陶器,”,which is related to an old Sansk,r,it,（梵语）,root meaning “to burn”.,Can be defined as inorganic compounds made by heating clay or other mineral matter to a high temperature at which they partially melt and bond together.,Ceramic can be defined as inorganic, nonmetallic materials.,陶器,-,瓷器,比较,表面效果制作材料,烧制温度敲击声音,陶瓷之别,陶器,瓷器,胎料,普通的粘土,瓷土（高岭土）,温度,一般,1100,度,表层,不施釉或低温釉,多施釉,吸水性,胎质粗松，断面吸水率高,胎体坚固致密，断面基本不吸水，敲之发出清脆的金属声响,9,Ceramics are refractory polycrystalline,（,多晶,）,compounds,Highly,inert (,惰性,),; biocompatible,(,生物适应性的）,Hard and brittle,（,脆性,）,High compressive strength,（,耐压强度,）,Generally good electric and thermal,insulators,(,绝缘,),Good aesthetic appearance,美观,Usually compound,化合,between,metallic and nonmetallic,elements,Always composed of more than one element,Bonds are partially or totally ionic, and may have combination of ionic,离子键,and covalent bonds,共价键,Majority,多数,has ionic (in salt compounds) or metallic and nonmetallic elements (as in oxides Al,2,O,3, MgO, SiO,2,),主要组分,：,硅酸盐化合物,在美国，陶瓷泛指硅酸盐材料，又称为传统陶瓷或普通陶瓷。包括日用陶瓷、工业用陶瓷、一般玻璃、水泥、耐火材料等。,先进无机材料,(advanced inorganic materials),:,用,氧化物,、,氮化物,、,硅化物,、,碳化,物,以至各种无机非金属化合物经过,特殊,的先进,工艺,制成的材料。,1.2,分类,Classification,12,Ceramics,traditional ceramics,:,derived and processed from clay or nonclay minerals including,refractories,（耐火材料,), white wares,cement(,水泥,),porcelain(,瓷器,), and structural clay ceramics.,advanced ceramics,:,high purity, better mechanical, electrical, magnetic, and optical properties,1.2.1,传统陶瓷,Traditional ceramics,：,又称普通陶瓷，主要是指以天然无机物如粘土等为主要原料、经高温处理得到的制品，主要用于制造日用器皿、生活洁具等生活用具。,瓷器,Porcelain; Chinaware,：细密的陶瓷器皿，质硬、半透明、白色、发 声清脆以及无孔，以长石,(Feldspar),、石英（,Quartz,）和高岭石,(Kaolin),为基本原料经一次烧成。,13,14,Traditional Ceramics,15,艺术陶瓷,16,1.2.2,先进陶瓷,Advanced ceramics,：,又称为精细陶瓷、新型陶瓷、高技术陶瓷、特种陶瓷等。,New,、,technical,、,engineering,、,advanced ceramics,是指以精制的高纯天然无机物或人工合成无机化合物为原料，采用精密控制的制造加工工艺烧结，得到的具有独特性能的高功能陶瓷。,21,Advanced ceramics,Advanced ceramics,are,developed form rather simple chemical compounds , and advances in processing which have provided greater control over their structures.,Advanced ceramic: the scale of the raw materials and microstructures, including the crystal grains, crystal interface, pores and defects is at the level of microns.,先进陶瓷，从原料、显微结构中所体现的晶粒、晶界、气孔、缺陷等在尺度上都是处在微米级的水平。,Classification based on applications,Advanced (New) Ceramic materials,Oxides Nitrides Carbides,Abrasives Rocket Engines Abrasives,研磨料,Bioceramics Gas Turbiness,燃气涡轮机,Resistance Heating,电阻加热,Electrical Cutting Tools Steel Additives,(Steel),Cutting Tools,High Temperatures,Refractory Brick Substrates,基板,Cutting Tools(cermets),耐火砖,For IC Chips,Glass Additives coatings Armor,Ceramic Matrix Composites,Nuclear Fuels,Reinforcing Fibers,Advanced Ceramics,Cutting tools,Zirconia toughened alumina,氧化锆增强氧化铝,24,25,红色陶瓷系列,黑色陶瓷系列,黄色陶瓷系列,密封环陶瓷系列,26,点火头系列,27,1.2.3,先进陶瓷的分类,组成,composition,：,氧化物,oxide,、,氮化物,nitride,、,硅化物,silicide,、,碳化物,carbide,性能,properties & applications,：,结构陶瓷,structural ceramics,、,功能陶瓷,functional ceramics,28,结构陶瓷,:,以力学、机械性能为主。,Mechanic properties,功能陶瓷,:,利用材料的电、磁、光、声、热等性能及其耦合效应，如铁电、压电陶瓷、敏感陶瓷、快离子导体陶瓷等。,主要从电性能上考虑有绝缘陶瓷、介电陶瓷、半导体陶瓷、导体陶瓷以至高临界温度的超导陶瓷。,29,1.3,陶瓷的发展,30,陶 器,瓷器（传统 陶 瓷 ）,高铝质粘土和瓷土的应用,釉 的 发 明,原 料 纯 化,陶瓷工艺的 发展,陶瓷理论的发展,先 进 陶 瓷（微米级）,纳 米 陶 瓷,高温技术的发展,显微结构 分析的进步,性能研究 的深入,无损评估的成就,相邻学科的推动,1.4 Applications,Thermal Barrier Coatings:,热屏蔽涂层,Low thermal conductivity,传导性,reduces metal temperatures,31,Electronics Packaging,电子封装,:,Ceramics:,Provide high temperature performance and thermal expansion coefficient match to Silicon,High thermal conductivity desired,32,Ceramic Armour,装甲,33,34,Some other examples,1.4,陶瓷的发展趋向,纳米陶瓷,nano-ceramic,特性：,原材料粉末,raw materials powder,颗粒为纳米级,nano-level grains,；,微观结构,microstructures,晶粒,grains,晶界,interfaces,，气孔,pores,以及 晶体缺陷,defects,同样在纳米级,nano-level,。,35,两种晶型复合的复相陶瓷：同一化 学组成的物质经适当的工艺控制,得到不同晶型和不同的颗粒形貌的复相陶瓷，达到自补强的目的。,有机和无机复合的复相陶瓷：介于有机与无机材料之间，不需要高温处理而获得的一种新型材料。,金属陶瓷：金属与陶瓷复合的复相陶瓷。,36,3.2 Structure of Ceramics,Crystalline solids composed of metallic and nonmetallic materials,Ceramics are crystal structures made of metallic ions and Inorganic materials,Bonding is either partially or completely ionic,离子键,.,（还有共价键,covalent bonds,）,Variables include,The magnitude,量级,of the electrical charge,电荷,on the ions;,The relative size of the ions,离子,37,Properties of Ceramics,Corrosion resistance,抗腐蚀, chemical inertness,惰性, thermal shock resistance,抗热震性,wear-resistance,耐磨,Electrical properties: solid electrolytes in experimental batteries and fuel cells,燃料电池,Other uses: include automotive sensors, packaging for integrated circuits, electronic/optical devices, fiber optics, microchips, and magnetic heads,38,3.2.1 Structure of ceramics,普通陶瓷的结构,Microstructure of ordinary ceramics,陶瓷是由金属（类金属）和非金属元素之间形成的化合物，其中的原子（离子,),主要以共价键或离子键相结合。陶瓷通常是一种多晶多相的聚集体。,39,普通陶瓷的显微结构主要由晶相、玻璃相、气相及晶界构成。,40,晶相,crystal phase,Crystal phase: the main phase in ceramic materials, and composed of some solid solutions and compoundsh,化合物,. Its structure and morphology,形态,decide the microstructure, properties and applications of ceramics.,41,Introduction,Structure of ceramics: most varies from relatively simple to highly complex.,Being compounds, ceramics are made of different types of atoms of varying sizes.,42,Silicate,硅酸盐,The basic structure unit: SiO4 tetrahedron,四面体,.,Oxygen (O) and silicon (Si) together account for about 75% of the earths crust.,43,Types: 1000 different silicates occur naturally, depending on the different ways the SiO,4,tetrahedra can be linked.,44,Clay,Clay: a complex mixture of silicates.,Silicates: are complex ionic compounds that are exceedingly numerous,数目众多,.,Clays: have sheets of linked SiO4 tetrahedra which slide over each other, giving their minerals a characteristic,soft feeling.,45,Characteristics of layered structures,Layered structure: as a,lubricant,润滑剂, water can,penetrate, producing a material that is pliable (,柔软的,) and slippery.,When heated: 1100,o,C in a kiln (,窑,),the water in clay is removed;,the layered sheets bond or lock into a rigid,structure.,The material with such a solid structure is called a ceramic.,46,Structures of silicates,Chain or ring structures: link by sharing the atoms in two corners of the SiO4 tetrahedrons.,Layered silicates: sharing three corner atoms. Such as: talc,滑石, kaolinite,高岭石,clay, mica,云母,.,Framework,框架,silicates: sharing four corner atoms.,47,Silica,二氧化硅,Pure silica: three polymorphs,晶型,cristobalite,方石英,tridymite,鳞石英,: high temperature,quartz,石英,: low temperature,It is the basic structure for glasses and many ceramics.,48,Structures Properties,Atoms,原子,are held strongly: the atoms are difficult to move or slip in relation to each other. the ductility,延展性,of ceramics is very low and they are brittle.,High shear stresses,Low ductility,High compressive strength,抗压强度,Low tensile strength,抗张强度,.,49,Bend strength: the maximum bending stress in tension of failure.,Metals VS ceramics:,at room temperature: they are competitive;,850,o,C, metals weaken while ceramics retain much of their strength.,Ceramics: good heat resistance.,alumina: 1800,o,C,silicon carbide: 1700,o,C,Ceramic Phase Diagrams,Microstructures: depending on the compositions, and the variables of temperature and pressure.,The desired microstructure: coming from the processing.,As the composition becomes more complex, the more the number of phases present themselves.,51,phase diagram,相平衡状态图，相图,The phase diagram, equilibrium, or constitutional diagram:,The map that shows the different compositions and the temperatures under equilibrium conditions.,（,Mullite,莫来石,3Al,2,O,3,-2SiO,2,）,52,莫来石（或莫乃石）是一系列由铝硅酸盐组成的矿物统称，这一类矿物比较稀少,。,莫来石,是铝硅酸盐在高温下,生成,的矿物，人工加热铝硅酸盐时会形成莫来石。天然的莫来石晶体为细长的针状且呈放射簇状。莫来石矿被用来,生产高温,耐火材料,。,耐火度,:,1800,o,C,时,仍很稳定,1810,o,C,分解,为刚玉和液,相,莫来石是一种优质的耐火材料，它具有,膨胀,均匀、热震稳定性极好、荷重软化点高、高温蠕变值小、硬度大、抗化学腐蚀性好等特点，目前主要有高纯电熔,莫来石,、普通电熔莫来石、全天然铝矾土精矿烧结莫来石和轻烧莫来石,。,适用于石油裂介炉、冶金热风炉、陶瓷辊道窑、隧道窑、电瓷抽屉窑、玻璃坩埚窑及各种电炉的内衬，可直接接触火焰,53,3.2.2 Microstructures of Ceramics,Porosity and Density,Mass density,质量密度, which uses the mass of a material divided by its volume refers to this theoretical density,Atomic weight is a major factor in determining the density of a material,Close-packed,密实的,metals are more dense than open-structured materials.,54,Brittle Fracture of Ceramics,脆性断裂,Defects,缺陷,in ceramics can develop due to internal stresses (,内应力,),and porosity,Thermal stresses due to an-isotropic thermal expansion,（各向异性热膨胀）,tend to crack weak grain boundaries,55,96%,dense alumina,56,Pores in partially sintered Alumina,部分烧结氧化铝中的孔隙,Green density,压坯密度,is the bulk density,体积密度,of a compact prior to its densification,密实化,.,In preparing particles for the production of powdered metals or ceramics, the packing of spherical shaped,球形, monosized,单一尺寸,(0.1m) particles, even when vibrated,振动,to settle the particles, does not achieve a density level much higher than 60%.,57,Despite tapping or vibrating, these particles do not rearrange themselves completely to eliminate,除去,pores.,The optimum density of spherical particles can be reached by varying the size distribution of particles to permit smaller particles (50 nm or less) to locate in the interstices (,空隙,) of the larger ones.,58,Ceramics are, by nature, generally porous,孔隙的,materials with varying degrees of porosity.,Bulk density,体积密度,is used in this instance to refer to a ceramics density, and it includes the materials porosity and the fact that most ceramics contain both a crystalline and a noncrystalline phase.,59,Open porosity,开口孔,refers to the network of pores in a material that is open to the surface and into which a liquid such as water can penetrate,渗透,if the part were submerged,浸入,init.,Closed porosity,闭口孔,refers to those pores that have become sealed within the grain structure.,60,Pores affect the strength of ceramics in two ways,：,First,，,they produce stress concentrations,应力集中,. Once the stress reaches a critical level, a crack will form and propagate,扩展,.,Second,，,pores reduce the cross-sectional areas over which a load can be applied and, consequently, lower the stress that these materials can support.,61,The amount, size, distribution,分布, and the continuity,连续性,of voids,空隙,in a ceramic are the principal factors that determine its properties,In general,，,porosity is detrimental,有害的,to ceramics properties. Grain boundary,晶粒界线,sliding, creep rate, and chemical reactions that attack the ceramic or reduce its melting point are more adverse,不利的,conditions produced by impurities and porosity.,62,63,收缩,a,收缩,b,收缩,无气孔的,多晶体,c,说明：,a,:,颗粒聚集,b,:,开口堆积体中颗,粒中心逼近,c,:,封闭堆积体中颗,粒中心逼近,3.3 Ceramic Processing,Traditional Processing,structural clay products and the whitewares.,Formation Drying Firing,成型,Forming,：,将粉料直接或间接地转变成具有一定形状、体积和强度坯体，称为素坯或生坯,(roughcast),。,成型的方法有很多，主要有可塑法、注浆法与压制法。,可塑成型,利用泥料的可塑性。将粉料与一定水份或塑化剂混合均匀，使之成为具有良好塑性的料团，再用手工或机械成型制成坯体。,注浆成型,即浆料成型法，是将原料配制成胶状浆料注入具有所需形状的模具中成型，又可分为注浆成型和热压注浆成型。,压制成型,将粉料填充在模型中，施加压力，制成具有一定现状和强度的坯体。,分类：普通压制成型和等静压制成型。适宜于干料,(,含水,3,7,),或半干料,(,含水,8,15,),。,Drying and Firing / Sintering,Drying: decrease layer size and spacing,常规烧结、热压烧结、气焚烧结、放电等离子烧结、微波烧结,造粒,成型,烧结,加工,检测,配料,预烧,根据确定的化学组 成,干压、注模、注浆、挤塑等,平整度,材料性能,粘接剂（,PVA,等），喷雾干燥,Schematic illustration,示意图,Sintering / firing,梭式窑,The roles of clay minerals:,Hydroplasticity,含水塑性,: by adding water, the clays become very plastic.,Dense & strong ceramics: clay fuses,融,合,or melts over a range of temperatures; then, producing a dense and strong ceramics during firing without complete melting so that the desired shape is maintained.,等离子放电烧结过程示意图,Advanced Ceramic Processing,制备工艺：不再以熔炉为主要烧结工具,如真空烧结、气氛烧结、热压烧结、气压烧结等。,性能：高强度、高硬度、耐腐蚀、导电、绝缘以及磁、电、光、生物相容性等。,Chemical processes,Sol-gel processing,Melt processing,Producing single-crystal materials,Vapor processing,Directed metal oxygen process,固相法：包括热分解法,(thermal decomposition),；非晶合金退火结晶法（在玻璃转变温度下结晶）；自蔓延高温合成方法（制备金属复合材料）。,液相法：包括沉淀法；水解法；溶胶,-,凝胶法（通过水解金属醇盐或金属无机盐来合成氧化物的一种化学方法）。,气相法：包括气相合成法；气相热分解法。,机械法：球磨、振动磨、高能球磨、气流粉碎。,溶剂蒸发法：酒精干燥法、冷冻干燥法、热石油工作法、喷雾工作法,液相法和气相法是制备超细粉的主要方法。,3.4 Properties of Ceramics,Mechanical properties,Physical properties,Chemical Properties,Fabricability,Other properties,Mechanical properties,No yield strength: ceramics do not plastically deform before reaching their tensile strength.,No permanent elongation or reduction in area: ceramics cannot be plastic deformed by room temperature.,Mechanical properties,Compressive strength: excellent, better than metals, plastics, and composites.,Hardness: highest in the engineering materials.,The long-term service characteristics of ceramics:,Fatigue resistance and creep strength: good,Tensile fatigue strength: poor.,Special Mechanical properties:,Good in compression,Very high hardness and greater stiffness than other engineering materials.,Weakness: brittleness,Physical properties,Compared to metals: ceramics are lightweight, but low density may also be an indicator of too much porosity in a particular grade.,As a structural material: the designer should select a ceramic with high theoretical density (99%).,The melting points of ceramics: are among the highest of all engineering materials.,The thermal conductivity and electrical conductivity: cover a large spectrum.,Most ceramics: electrical insulators, but some are semiconducting.,Thermal expansion: lower than metals and plastics.,Chemical Properties,Resistant to chemical attack:,the engineering ceramics, aluminum oxide, silicon carbide, zirconia, silicon nitride, and others, are very resistant to chemical attack in a wide variety of solutes.,Fabricability,They cannot be plastically deformed to shapes at room temperatures.,Ceramics cannot be melted and cast to shapes like metals, mostly because of their high melting temperatures.,The machining of ceramics is so costly that it is not an option for many machine parts.,Other properties,Wear Resistance,Thermal Shock Resistance,Applications of Ceramics,Can withstand volatile and high-temperature conditions encountered in the processing of metals.,The chemical, petroleum, energy conversion, glass and other ceramic industries all rely upon refractory materials.,Uses in the Construction Industry:,Areas such as commercial buildings, residential homes, highways, bridges, and water and sewer systems.,Products such as floor, wall and roofing tile, cement, brick, gypsum, sewer pipe, and glass are the building blocks in the world of construction.,Lighting Electrical:,Glass properties of hardness, transparency, and its ability to withstand high temperatures and hold a vacuum at the same time made the light bulb a reality.,Electrical Applications,Electrical properties of ceramics: insulating, semi-conducting, superconducting, piezo-electric and magnetic.,Products: cell phones, computers, television, other electronic products.,Magnetic storage,Communication,Optical fibers: are a reliable conduit for delivering an array of interactive services, using combinations of voice, data and video.,Medical:,Bioceramic materials: are used for repair and replacement of human hips, knees, and other body parts.,Ceramic materials: can stimulate bone growth, promote tissue formation and provide protection from the immune system.,Environmental and Space Applications,To decrease pollution, capture toxic materials and encapsulate nuclear waste;,Catalytic converters in trucks and cars are made of cellular ceramics and help convert noxious hydrocarbons and carbon monoxide gases into harmless carbon dioxide and water.,Advanced ceramics: used in diesel and automotive engines:,Its light-weight, high-temperature and wear resistant properties results in more efficient combustion and significant fuel savings.,