原子结构和晶体结构.ppt

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Objectives of Chapter 1
The goal of this chapter is to describe the underlying physical concepts related to the structure of matter.
To examine the relationships between structure of atoms-bonds-properties of engineering materials.
Learn about different levels of structure . atomic structure, nanostructure, microstructure, and macrostructure.
To learn classification of materials based on atomic/ionic arrangements
To describe the arrangements in crystalline solids based on lattice, basis, and crystal structure
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Chapter Outline




、晶向和晶面


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Nanotechnology
Micro-electro-mechanical (MEMS) systems-Airbag sensors
Nanostructures
Figure
The Structure of Materials: Technological Relevance
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position)和结构(structure)对于材料的性能具有重要的影响。
微观结构是尺寸范围在~10到1000nm的材料结构。微观结构一般包含材料的平均晶粒尺寸、晶粒尺寸分布、晶粒取向和与缺陷有关的特征。
宏观结构是宏观水平在~>1000nm材料结构。宏观结构主要包括气孔率,表面喷涂,内部和外部宏观裂纹等内容。
原子结构包括构成材料整体的所有的原子和原子排列。在材料整体的内部存在着纳米、微观和宏观结构。
根据原子排列的特点,可以区分材料是非晶体还是晶体。非晶体中原子或离子具有短程有序,长程无序的排列。晶体中原子或离子具有短程和长程均有序的排列。
The Structure of Materials: Technological Relevance
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Level of Structure Example of Technologies
原子结构~10-10m 金刚石–刀具刃口涂层
原子排列:长程有序 PZT锆钛酸铅-点燃气体
~10-10-10-9m,
有序化范围:
几cm大晶体
原子排列:长程有序非晶硅-光纤通讯工业
~10-10-10-9m
表1-1 结构层面
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Level of Structure Example of Technologies
纳米结构纳米氧化铁-铁磁流体
~10-9-10-7m
1-100nm)
微观结构金属和合金的机械性能
~10-8-10-6m
(10-1000nm)

宏观结构汽车防腐蚀涂层
~>10-4m
(1000nm)
Table (Continued)
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Section The Structure of the Atom
The atomic number of an element is equal to the number of electrons or protons in each atom.
The atomic mass of an element is equal to the average number of protons and neutrons in the atom.
The Avogadro number of an element is the number of atoms or molecules in a mole.
The atomic mass unit of an element is the mass of an atom expressed as 1/12 the mass of a carbon atom.
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原子结构
原子由原子核及分布在核周围的电子所组成。原子核内有中子和带正电的质子。所以,原子是由原子中心带正电的原子核和核外绕核高速旋转的带负电的电子所构成。×10-