题目：
系别：
专业：
学制：
姓名：
学号：
导师：Hefei University 陶瓷材料 Ceramic materials
化学工程系 09无机非专业 四年 孙改行 谢劲松
Ceramic materials
[ Abstract ]: ceramic materials in our daily lives is a very important material, especially in our China, making ceramic since ancient times is our specialty. To the modern ceramics and the concept of functional happened a series of change, this paper focuses on the properties of ceramic materials, application and development prospect of doing a simple overview
[ Key words ]: ceramics, materials
Text: 1, overview: traditional ceramic material is clay, quartz, feldspar and other silicate materials, and modern ceramic materials are inorganic non-metallic materials collectively. Ceramic material is a kind of natural or synthetic powdered compounds, after molding or sintered at high temperature, the metal elements and non-metallic inorganic compounds constitute heterogeneous solid materials. Ceramic material with high temperature
resistance, corrosion resistance, wear resistance, abundant raw materials, low cost and many other advantages which are people who have been concerned. Now, ceramic
materials, metal materials, polymer materials are called the three major solid materials. 2, performance: ( 1): mechanical properties of ceramic materials with high hardness and excellent wear resistance, high elastic modulus, the tensile strength of steel of low compressive strength is high, the ceramic plastic, low toughness, brittle, almost no plasticity at room temperature.
( 2) mechanical properties : most of the ceramic hardness than the metal is much higher, especially good, often used as wear-resistant parts ( such as bearings, tool ). It has high elastic modulus and high brittleness, low tensile strength and high compressive strength, has strong heat function, with high temperature characteristics, its melting point is generally greater than 2000 DEG C. In addition, ceramic material also has a smaller thermal expansion coefficient, thermal conductivity, thermal capacity is small and low mechanical properties.
( 3): most of electrical properties of ceramic materials with high resistivity, low dielectric constant and dielectric loss, so it can be used as insulating material. A few of the ceramic materials can be used as the semiconductor material, and has become a radio technology and high-tech industry indispensable material. Some ceramic material also has a superconducting characteristics, with superconducting properties, high temperature superconducting materials ceramics has become an important part in.
( 4): chemical properties of ceramic materials with high temperature oxidation, corrosion resistant ability. It is not only the acid, alkali, salt has good resistance effect, but also on
the molten metal with the corrosion effect. So ceramic material used for chemical reaction generator, used as an ion exchange membrane. Some ceramic materials may also contain carriers on catalytic effect of chemical reaction.
( 5) the biological properties of ceramic materials: biological function mainly displays in to repair or replace some human tissue, organ or enhance organ function aspect. For example, artificial cavity membrane pacemaker battery plate, a hearing aid using a vibrating plate. In addition, a ceramic material has the function of human perception.
( 6): optical properties of some ceramic materials with light absorption, light reflection and light offset characteristics, there is light, and the light of photosensitive. Some advanced optical ceramic material has good light transmittance. Use of ceramic materials for these optical properties can be manufactured many of optical products, such as production of special lamps ( such as Na lamp ) of the tube material, ceramic sensitometer etc..
3, application: ( 1), nano ceramic material: nanometer ceramic refers to nanotechnology study based on development has more characteristics of ceramic materials. The microstructure, particle size, distribution of the second phase, the pore size of
equidimensional are in nanometer scale ( 0.1nm to 100nm) level, so that the material strength, toughness and superplasticity greatly improved. We all know the common ceramic microstructure is mainly composed of crystal, glass phase and gas phase composition, phase composition, structure, shape, number and distribution of ceramic material directly influence the properties of glass phase and gas phase, and the content of the larger will make ceramic strength, hardness and resistance to thermal shock such reduced performance. Nano ceramic material appear well overcomes these
disadvantages of ordinary ceramic materials. And the mechanical, electrical, chemical, light
Science, magnetic properties have a significant impact, as an alternative to ordinary ceramic materials.
By opening up a new domain.
Nano ceramics mainly lies in the mechanical properties, including hardness, fracture toughness and low temperature ductility. In these aspects of nanocrystalline ceramics have been greatly improved, especially under high temperature has greater hardness, strength. Nano ceramic also under Lower Temperature Sintering Densification superiority can be achieved. In room temperature compression, nanometer particle has good
combination, higher than 500℃soon densification and grain size, only slightly increased, the hardness and fracture toughness value is better, and the sintering temperature is lower than the engineering ceramics in 400℃ ~ 600 ℃, and without any additives
sintering. Nano hardness and fracture toughness increases with the increase of sintering temperature, the low temperature sintering to obtain better mechanical properties. Usually, ordinary ceramic is a brittle material, can't afford to thermal shock and mechanical shock, but nano zirconia ceramics has become a ductile material, at room temperature can be
bent, plastic deformation up to 100%. Nanometer ceramics can be shown to have significant quantum effect, can make originally not light, opaque ceramic become luminescent ceramic and transparent ceramics, and can greatly improve the
electromagnetic characteristics of semiconductor ceramic material. With the development of high technology, nano ceramic more intensive study will then cause the whole ceramic research field extension. People on the nano ceramic place the very big hope, now in the world many countries have invested a lot of money and manpower to the nanometer ceramic materials for further research. Can foreknow, nano ceramic materials will be better tomorrow.
( 2), intelligent ceramic materials ceramic materials include: intelligent sensitive to environment and on climate change
Sensitive response of materials, has now become the materials science and Engineering in the field of window. Intelligent ceramic functional materials, including driving system and feedback system combined with intelligent material systems and structures. Because of its comprehensive functions, it can be timely perception and response the change of external environment, self monitoring, self diagnosis, self protection, self adaptation and many other properties. The functional ceramic materials will be smart ceramics and components design and development using the main core material.
At present some functional ceramic products has a intelligent functions, such as
semiconductor barium titanate positive temperature coefficient thermal resistor and the zinc oxide varistor, the voltage and the temperature has own diagnosis, repair and self protection function. In the intelligent system of ceramic, piezoelectric ceramics are an important class of. As a result of piezoelectric ceramic with force, electric, acoustic, thermal, optical and other functional and coupling effect, can be used as a pressure,
temperature, light, sound and other aspects of the sensor. The piezoelectric actuator has a displacement of high control precision, fast response, large driving force, driving power and wide frequency range and other advantages, so often the use of piezoelectric ceramic materials for structural damping, vibration control, structural damage and active noise control. Now widely used and is planning to develop the piezoelectric ceramic products and materials system having intelligent windscreen wiper, ceramic sonar system,
pyroelectric voltage transformer and senior car shock absorber. In the intelligent ceramic material, and is sensitive to temperature changes and can make a certain reaction thermal ceramic, capable of monitoring to toxic or flammable gas sensitive ceramics, can be generated under the irradiation of light photoconductive or voltaic effect photosensitive ceramic and can detect the ambient humidity humidity ceramic.
Intelligent ceramic materials research and development are just emerging period, it will be applied to automobile, shipbuilding, aviation, machinery, household electrical appliances, aerospace, defense, construction and other industrial fields have an important impact, greatly improve the intelligence and automation level, enabling the operation to be more concise and more humane. Can say intelligent ceramic materials the development of promising.
陶瓷材料
【摘要】：陶瓷材料是我们日常生活中一种非常重要的材料，尤其是在我们中国，制作陶瓷自古以来就是我们的专长。到了现代陶瓷的概念和功能发生了一系列的变化，本文主要对陶瓷材料的性能，应用以及发展前景做一个简单的概述
【关键字】：陶瓷，材料
正文：
1，概述：传统的陶瓷材料是粘土、石英、长石等硅酸盐材料，而现代陶瓷材料是无机非金属材料的统称。
陶瓷材料是一种天然或人工合成的粉状化合物, 经过成型或高温烧结,由金属元素和非金属的无机化合物构成的多相固体材料。陶瓷材料具有耐高温、耐腐蚀、耐磨损、原料丰富、成本低廉等诸多优点而被人一直关注。现在,陶瓷材料、金属材料、高分子材料被称为三大主要固体材料 。
2，性能：
(1) 力学性能：陶瓷材料具有极高的硬度和优良的耐磨性，弹性模量高，钢度大抗拉强度低抗压强度很高，陶瓷的塑性、韧性低，脆性大，在室温下几乎没有塑性。
(2) 机械性能 :大多数陶瓷的硬度都比金属高的多,特别好, 常用作耐磨零件(如轴承, 刀具).它具有高的弹性模量和高脆性,具有低的抗拉强度和高的抗压强度, 具有较强的耐热功能,具有耐高温的特性, 其熔点一般大于2000℃。此外, 陶瓷材料还具有热膨胀系数较小 、导热性较低 、热容量较小等机械特性 。
(3) 电学性能：大多数陶瓷材料有较高的电阻率 、较小的介电常数和介电损耗, 因此它可以用作绝缘材料。少数的陶瓷材料可以用作半导体材料,而且已经成为无线电技术和高新技术领域不可或缺的材料。有的陶瓷材料还具有超导特性,，具有超导特性的陶瓷已经成为高温超导材料中的重要组成部分 。
(4) 化学性能：陶瓷材料具有抗高温氧化、抗腐蚀的能力。它不仅对酸 、碱 、盐具有良好的抵抗作用,而且还对熔融金属具有抗蚀作用 。所以陶瓷材料常用作化学反应 的发生器、用作离子交换膜。有的陶瓷材料还可以含载体对化学反应有催化作用。
(5) 生物性能：陶瓷材料 的生物功能主要表现在可 以修复或替换人体 的某些组织 、器官或增强脏器功能的方面 。比如人造腔膜 、心脏起搏器用 电池板 、助 听器用振动板等 。另外, 有 的陶瓷材料还具有人体感知功能 。
(6) 光学性能：某些陶瓷材料具有光吸收、光反射及光偏移的特性,还有的具有分光性 、感光性及导光性。一些先进光学陶瓷材料还具有良好的透光性 。利用 陶瓷材料 的这些光特性可 以制造 出许 多光学产 品, 例 如制作特种灯 具(比如 Na灯) 的灯管材料 、陶瓷感光计等等 。
3，应用：
（1），纳米陶瓷材料：纳米陶瓷是指在纳米技术的基础上研究开发的具有更高更多特性陶瓷材料。在陶瓷材料的显微结构中, 相粒尺寸、 第二相分布、 气孔尺寸等量纲均在纳米量级 ( 0.1nm至 100nm) 的水平上, 因此使得材料的强度、 韧性和超塑性大幅度提高。我们都知道普通陶瓷材料的显微组织主要由晶体相、 玻璃相及气相组成, 各相的组成、 结构、 数量、 形状与分布都对陶瓷材料的性能有直接的影响, 而玻璃相及气相的含量较大会使陶瓷的强度、硬度和抗热冲击等性能降低。纳米陶瓷材料的出现很好地克服了普通陶瓷材料这些缺点。并且对材料的力学、 电学、 化学、 光
学、 磁学等性能产生重要影响, 为替代普通陶瓷材料的应
用开拓了新的领域。
纳米陶瓷的特性主要在于力学性能方面, 包括材料的硬度、 断裂韧度和低温延展性等。在
这些方面纳米陶瓷材料都有了很大的提高, 特别是在高温下具有更大的硬度、 强度。纳米陶瓷还具有在较低温度下烧结就能达到致密化的优越性。在室温压缩时, 纳米颗粒已有很好的结合, 高于 500℃就很快致密化, 而晶粒大小只有稍许的增加, 所得的硬度和断裂韧度值更好, 而烧结温度却比工程陶瓷低 400℃～ 600℃, 并且烧结不需要任何的添加剂。纳米陶瓷的硬度和断裂韧度随烧结温度的增加而增加, 故低温烧结能获得更好的力学性能。通常情况下, 普通陶瓷是脆性材料, 经不起热冲击和机械冲击, 但纳米氧化锆陶瓷却变成了韧性材料, 在室温下就可以弯曲, 范性形变高达 100%。纳米陶瓷可显示出有重大意义的量子效应, 可以使本来不发光、不透光的陶瓷变成发光陶瓷和透明陶瓷, 并且可以大大改善半导体陶瓷材料的电磁特性。随着高技术的不断出现, 纳米陶瓷的更深入研究必将再引起整个陶瓷研究领域的扩展。人们对纳米陶瓷寄予非常大的希望, 现在世界上很多国家都投入了大量的资金和人力对纳米陶瓷材料进行更深入的研究。可以预见, 纳米陶瓷材料的明天会更好。
（2），智能陶瓷材料：智能陶瓷材料包括对环境敏感且能对环境变化作出
灵敏反应的材料, 目前已成为材料科学及工程领域中研究的亮点。智能陶瓷包括功能材料、 驱动系统与反馈系统结合的智能材料系统或结构。由于其综合性功能的发挥,它可适时感知与响应外界环境的变化, 实现自我监测、 自我诊断、 自我保护、 自我适应等诸多性能。其中功能陶瓷材料将是智能陶瓷及其器件进行设计与发展使用的主要核心材料。
当前有些功能陶瓷制品已具有智能化的功能, 如半导体钛酸钡正温度系数热能电阻及氧化锌变阻器, 它们对于电压和温度已经具备自身诊断、 自身修复与自我保护的功能。在智能陶瓷系统中, 压电陶瓷是重要的一类。由于压电陶瓷具有力、 电、 声、 热、 光等多种功能及耦合效应, 可以用作压力、 温度、 光、 声等多方面的传感器。压电驱动器又具有位移控制精度高、 响应快、 推动力大、 驱动功率低和工作频率宽等优点, 所以常使用压电陶瓷材料用于结构减震、 震动控制、 结构破坏及有源消声等。现在已经普及使用及正拟开发研制的压电类智能陶瓷制品及材料系统有智能雨刷、 陶瓷声纳系统、 热释电电压变压器及高级轿车减震装置。在智能陶瓷材料里, 还有对温度变化敏感并能做出一定反应的热敏陶瓷, 能够监测到有毒或易燃气体的气敏陶瓷, 能够在光的照射下产生光导电或伏特效应的光敏陶瓷及能检测出环境湿度的湿敏陶瓷。
智能陶瓷材料的开发研究正处于刚刚兴起时期, 它的应用将会对汽车、 造船、 航空、 机械、 家电、 航天、 国防、建筑等工业领域产生重要影响, 大大提高其智能与自动化的水平, 使操作更简洁更人性化。可以说智能陶瓷材料的发展前途无量。
请假条
尊敬的谢老师：
我因驾照理论考试，所以本周二上午不能准时上课，特此请假，望批准。
孙改行
0903031011
2012.11.20
题目：
系别：
专业：
学制：
姓名：
学号：
导师：Hefei University 陶瓷材料 Ceramic materials
化学工程系 09无机非专业 四年 孙改行 谢劲松
Ceramic materials
[ Abstract ]: ceramic materials in our daily lives is a very important material, especially in our China, making ceramic since ancient times is our specialty. To the modern ceramics and the concept of functional happened a series of change, this paper focuses on the properties of ceramic materials, application and development prospect of doing a simple overview
[ Key words ]: ceramics, materials
Text: 1, overview: traditional ceramic material is clay, quartz, feldspar and other silicate materials, and modern ceramic materials are inorganic non-metallic materials collectively. Ceramic material is a kind of natural or synthetic powdered compounds, after molding or sintered at high temperature, the metal elements and non-metallic inorganic compounds constitute heterogeneous solid materials. Ceramic material with high temperature
resistance, corrosion resistance, wear resistance, abundant raw materials, low cost and many other advantages which are people who have been concerned. Now, ceramic
materials, metal materials, polymer materials are called the three major solid materials. 2, performance: ( 1): mechanical properties of ceramic materials with high hardness and excellent wear resistance, high elastic modulus, the tensile strength of steel of low compressive strength is high, the ceramic plastic, low toughness, brittle, almost no plasticity at room temperature.
( 2) mechanical properties : most of the ceramic hardness than the metal is much higher, especially good, often used as wear-resistant parts ( such as bearings, tool ). It has high elastic modulus and high brittleness, low tensile strength and high compressive strength, has strong heat function, with high temperature characteristics, its melting point is generally greater than 2000 DEG C. In addition, ceramic material also has a smaller thermal expansion coefficient, thermal conductivity, thermal capacity is small and low mechanical properties.
( 3): most of electrical properties of ceramic materials with high resistivity, low dielectric constant and dielectric loss, so it can be used as insulating material. A few of the ceramic materials can be used as the semiconductor material, and has become a radio technology and high-tech industry indispensable material. Some ceramic material also has a superconducting characteristics, with superconducting properties, high temperature superconducting materials ceramics has become an important part in.
( 4): chemical properties of ceramic materials with high temperature oxidation, corrosion resistant ability. It is not only the acid, alkali, salt has good resistance effect, but also on
the molten metal with the corrosion effect. So ceramic material used for chemical reaction generator, used as an ion exchange membrane. Some ceramic materials may also contain carriers on catalytic effect of chemical reaction.
( 5) the biological properties of ceramic materials: biological function mainly displays in to repair or replace some human tissue, organ or enhance organ function aspect. For example, artificial cavity membrane pacemaker battery plate, a hearing aid using a vibrating plate. In addition, a ceramic material has the function of human perception.
( 6): optical properties of some ceramic materials with light absorption, light reflection and light offset characteristics, there is light, and the light of photosensitive. Some advanced optical ceramic material has good light transmittance. Use of ceramic materials for these optical properties can be manufactured many of optical products, such as production of special lamps ( such as Na lamp ) of the tube material, ceramic sensitometer etc..
3, application: ( 1), nano ceramic material: nanometer ceramic refers to nanotechnology study based on development has more characteristics of ceramic materials. The microstructure, particle size, distribution of the second phase, the pore size of
equidimensional are in nanometer scale ( 0.1nm to 100nm) level, so that the material strength, toughness and superplasticity greatly improved. We all know the common ceramic microstructure is mainly composed of crystal, glass phase and gas phase composition, phase composition, structure, shape, number and distribution of ceramic material directly influence the properties of glass phase and gas phase, and the content of the larger will make ceramic strength, hardness and resistance to thermal shock such reduced performance. Nano ceramic material appear well overcomes these
disadvantages of ordinary ceramic materials. And the mechanical, electrical, chemical, light
Science, magnetic properties have a significant impact, as an alternative to ordinary ceramic materials.
By opening up a new domain.
Nano ceramics mainly lies in the mechanical properties, including hardness, fracture toughness and low temperature ductility. In these aspects of nanocrystalline ceramics have been greatly improved, especially under high temperature has greater hardness, strength. Nano ceramic also under Lower Temperature Sintering Densification superiority can be achieved. In room temperature compression, nanometer particle has good
combination, higher than 500℃soon densification and grain size, only slightly increased, the hardness and fracture toughness value is better, and the sintering temperature is lower than the engineering ceramics in 400℃ ~ 600 ℃, and without any additives
sintering. Nano hardness and fracture toughness increases with the increase of sintering temperature, the low temperature sintering to obtain better mechanical properties. Usually, ordinary ceramic is a brittle material, can't afford to thermal shock and mechanical shock, but nano zirconia ceramics has become a ductile material, at room temperature can be
bent, plastic deformation up to 100%. Nanometer ceramics can be shown to have significant quantum effect, can make originally not light, opaque ceramic become luminescent ceramic and transparent ceramics, and can greatly improve the
electromagnetic characteristics of semiconductor ceramic material. With the development of high technology, nano ceramic more intensive study will then cause the whole ceramic research field extension. People on the nano ceramic place the very big hope, now in the world many countries have invested a lot of money and manpower to the nanometer ceramic materials for further research. Can foreknow, nano ceramic materials will be better tomorrow.
( 2), intelligent ceramic materials ceramic materials include: intelligent sensitive to environment and on climate change
Sensitive response of materials, has now become the materials science and Engineering in the field of window. Intelligent ceramic functional materials, including driving system and feedback system combined with intelligent material systems and structures. Because of its comprehensive functions, it can be timely perception and response the change of external environment, self monitoring, self diagnosis, self protection, self adaptation and many other properties. The functional ceramic materials will be smart ceramics and components design and development using the main core material.
At present some functional ceramic products has a intelligent functions, such as
semiconductor barium titanate positive temperature coefficient thermal resistor and the zinc oxide varistor, the voltage and the temperature has own diagnosis, repair and self protection function. In the intelligent system of ceramic, piezoelectric ceramics are an important class of. As a result of piezoelectric ceramic with force, electric, acoustic, thermal, optical and other functional and coupling effect, can be used as a pressure,
temperature, light, sound and other aspects of the sensor. The piezoelectric actuator has a displacement of high control precision, fast response, large driving force, driving power and wide frequency range and other advantages, so often the use of piezoelectric ceramic materials for structural damping, vibration control, structural damage and active noise control. Now widely used and is planning to develop the piezoelectric ceramic products and materials system having intelligent windscreen wiper, ceramic sonar system,
pyroelectric voltage transformer and senior car shock absorber. In the intelligent ceramic material, and is sensitive to temperature changes and can make a certain reaction thermal ceramic, capable of monitoring to toxic or flammable gas sensitive ceramics, can be generated under the irradiation of light photoconductive or voltaic effect photosensitive ceramic and can detect the ambient humidity humidity ceramic.
Intelligent ceramic materials research and development are just emerging period, it will be applied to automobile, shipbuilding, aviation, machinery, household electrical appliances, aerospace, defense, construction and other industrial fields have an important impact, greatly improve the intelligence and automation level, enabling the operation to be more concise and more humane. Can say intelligent ceramic materials the development of promising.
陶瓷材料
【摘要】：陶瓷材料是我们日常生活中一种非常重要的材料，尤其是在我们中国，制作陶瓷自古以来就是我们的专长。到了现代陶瓷的概念和功能发生了一系列的变化，本文主要对陶瓷材料的性能，应用以及发展前景做一个简单的概述
【关键字】：陶瓷，材料
正文：
1，概述：传统的陶瓷材料是粘土、石英、长石等硅酸盐材料，而现代陶瓷材料是无机非金属材料的统称。
陶瓷材料是一种天然或人工合成的粉状化合物, 经过成型或高温烧结,由金属元素和非金属的无机化合物构成的多相固体材料。陶瓷材料具有耐高温、耐腐蚀、耐磨损、原料丰富、成本低廉等诸多优点而被人一直关注。现在,陶瓷材料、金属材料、高分子材料被称为三大主要固体材料 。
2，性能：
(1) 力学性能：陶瓷材料具有极高的硬度和优良的耐磨性，弹性模量高，钢度大抗拉强度低抗压强度很高，陶瓷的塑性、韧性低，脆性大，在室温下几乎没有塑性。
(2) 机械性能 :大多数陶瓷的硬度都比金属高的多,特别好, 常用作耐磨零件(如轴承, 刀具).它具有高的弹性模量和高脆性,具有低的抗拉强度和高的抗压强度, 具有较强的耐热功能,具有耐高温的特性, 其熔点一般大于2000℃。此外, 陶瓷材料还具有热膨胀系数较小 、导热性较低 、热容量较小等机械特性 。
(3) 电学性能：大多数陶瓷材料有较高的电阻率 、较小的介电常数和介电损耗, 因此它可以用作绝缘材料。少数的陶瓷材料可以用作半导体材料,而且已经成为无线电技术和高新技术领域不可或缺的材料。有的陶瓷材料还具有超导特性,，具有超导特性的陶瓷已经成为高温超导材料中的重要组成部分 。
(4) 化学性能：陶瓷材料具有抗高温氧化、抗腐蚀的能力。它不仅对酸 、碱 、盐具有良好的抵抗作用,而且还对熔融金属具有抗蚀作用 。所以陶瓷材料常用作化学反应 的发生器、用作离子交换膜。有的陶瓷材料还可以含载体对化学反应有催化作用。
(5) 生物性能：陶瓷材料 的生物功能主要表现在可 以修复或替换人体 的某些组织 、器官或增强脏器功能的方面 。比如人造腔膜 、心脏起搏器用 电池板 、助 听器用振动板等 。另外, 有 的陶瓷材料还具有人体感知功能 。
(6) 光学性能：某些陶瓷材料具有光吸收、光反射及光偏移的特性,还有的具有分光性 、感光性及导光性。一些先进光学陶瓷材料还具有良好的透光性 。利用 陶瓷材料 的这些光特性可 以制造 出许 多光学产 品, 例 如制作特种灯 具(比如 Na灯) 的灯管材料 、陶瓷感光计等等 。
3，应用：
（1），纳米陶瓷材料：纳米陶瓷是指在纳米技术的基础上研究开发的具有更高更多特性陶瓷材料。在陶瓷材料的显微结构中, 相粒尺寸、 第二相分布、 气孔尺寸等量纲均在纳米量级 ( 0.1nm至 100nm) 的水平上, 因此使得材料的强度、 韧性和超塑性大幅度提高。我们都知道普通陶瓷材料的显微组织主要由晶体相、 玻璃相及气相组成, 各相的组成、 结构、 数量、 形状与分布都对陶瓷材料的性能有直接的影响, 而玻璃相及气相的含量较大会使陶瓷的强度、硬度和抗热冲击等性能降低。纳米陶瓷材料的出现很好地克服了普通陶瓷材料这些缺点。并且对材料的力学、 电学、 化学、 光
学、 磁学等性能产生重要影响, 为替代普通陶瓷材料的应
用开拓了新的领域。
纳米陶瓷的特性主要在于力学性能方面, 包括材料的硬度、 断裂韧度和低温延展性等。在
这些方面纳米陶瓷材料都有了很大的提高, 特别是在高温下具有更大的硬度、 强度。纳米陶瓷还具有在较低温度下烧结就能达到致密化的优越性。在室温压缩时, 纳米颗粒已有很好的结合, 高于 500℃就很快致密化, 而晶粒大小只有稍许的增加, 所得的硬度和断裂韧度值更好, 而烧结温度却比工程陶瓷低 400℃～ 600℃, 并且烧结不需要任何的添加剂。纳米陶瓷的硬度和断裂韧度随烧结温度的增加而增加, 故低温烧结能获得更好的力学性能。通常情况下, 普通陶瓷是脆性材料, 经不起热冲击和机械冲击, 但纳米氧化锆陶瓷却变成了韧性材料, 在室温下就可以弯曲, 范性形变高达 100%。纳米陶瓷可显示出有重大意义的量子效应, 可以使本来不发光、不透光的陶瓷变成发光陶瓷和透明陶瓷, 并且可以大大改善半导体陶瓷材料的电磁特性。随着高技术的不断出现, 纳米陶瓷的更深入研究必将再引起整个陶瓷研究领域的扩展。人们对纳米陶瓷寄予非常大的希望, 现在世界上很多国家都投入了大量的资金和人力对纳米陶瓷材料进行更深入的研究。可以预见, 纳米陶瓷材料的明天会更好。
（2），智能陶瓷材料：智能陶瓷材料包括对环境敏感且能对环境变化作出
灵敏反应的材料, 目前已成为材料科学及工程领域中研究的亮点。智能陶瓷包括功能材料、 驱动系统与反馈系统结合的智能材料系统或结构。由于其综合性功能的发挥,它可适时感知与响应外界环境的变化, 实现自我监测、 自我诊断、 自我保护、 自我适应等诸多性能。其中功能陶瓷材料将是智能陶瓷及其器件进行设计与发展使用的主要核心材料。
当前有些功能陶瓷制品已具有智能化的功能, 如半导体钛酸钡正温度系数热能电阻及氧化锌变阻器, 它们对于电压和温度已经具备自身诊断、 自身修复与自我保护的功能。在智能陶瓷系统中, 压电陶瓷是重要的一类。由于压电陶瓷具有力、 电、 声、 热、 光等多种功能及耦合效应, 可以用作压力、 温度、 光、 声等多方面的传感器。压电驱动器又具有位移控制精度高、 响应快、 推动力大、 驱动功率低和工作频率宽等优点, 所以常使用压电陶瓷材料用于结构减震、 震动控制、 结构破坏及有源消声等。现在已经普及使用及正拟开发研制的压电类智能陶瓷制品及材料系统有智能雨刷、 陶瓷声纳系统、 热释电电压变压器及高级轿车减震装置。在智能陶瓷材料里, 还有对温度变化敏感并能做出一定反应的热敏陶瓷, 能够监测到有毒或易燃气体的气敏陶瓷, 能够在光的照射下产生光导电或伏特效应的光敏陶瓷及能检测出环境湿度的湿敏陶瓷。
智能陶瓷材料的开发研究正处于刚刚兴起时期, 它的应用将会对汽车、 造船、 航空、 机械、 家电、 航天、 国防、建筑等工业领域产生重要影响, 大大提高其智能与自动化的水平, 使操作更简洁更人性化。可以说智能陶瓷材料的发展前途无量。
请假条
尊敬的谢老师：
我因驾照理论考试，所以本周二上午不能准时上课，特此请假，望批准。
孙改行
0903031011
2012.11.20