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纳米非晶材料的力学性能表征

时间:2018-04-13 22:50来源:毕业论文
纳米压痕仪可便捷的获得硬度、弹性模量等数据,并有精度好、可控性强的优势。本文测得NiP非晶薄膜硬度在6.6GPa左右,弹性模量为145GPa左右。NiP薄膜为硬膜软基底材料随压入深度增大

摘要纳米非晶材料具有原子间距和密度可改变的特点,通过退火或强烈的塑性变形手段处理,可以得到不同性质的非晶材料。同时非晶材料没有晶界,其力学性能往往优于晶体。小尺寸非晶材料更因尺寸特征有良好的力学性能,例如高硬度、高耐磨性、与大尺寸非晶相比稍好的塑性等。力学性能的改变能反应非晶材料结构变化,指导其设计。纳米压痕仪可便捷的获得硬度、弹性模量等数据,并有精度好、可控性强的优势。本文测得NiP非晶薄膜硬度在6.6GPa左右,弹性模量为145GPa左右。NiP薄膜为硬膜软基底材料随压入深度增大,受基底影响增大,硬度、弹性模量下降。同时蠕变、回弹现象速度敏感,它们随压入速度的增大而变得明显。纳米非晶并没有因塑性不均匀产生的锯齿流变现象。21156
关键词  非晶薄膜,纳米压痕仪,力学性能,蠕变,塑性变形
毕业论文设计说明书(论文)外文摘要
Title  Mechanical characterization of nanoglass                  
Abstract
Nano metallic glass has the characteristics that atomic spacing and density can be changed. We can have different kind of metal glass by annealing or strong plastic deformation. As there′s no grain boundary in metal glass, its mechanical properties are often better than crystal. Dimensional effect makes nano metallic glass has even better mechanical properties, such as high hardness, high wear resistance, better plasticity compared with metal glass. The changes of mechanical properties can reflect changes in the   structure and guide the design of it. Nano indenter can obtain hardness, elastic modulus, and other data in a convenient way and have advertisement on control and accuracy. I measured the hardness of thin film Nano metallic glass for about 6.6GPa, the elastic modulus for about 145GPa. NiP film which is a kind of dural soft base material, affected by the substrate more serious like hardness and elastic modulus decreased as the indentation depth increases. Meanwhile, creep and rebound are velocity sensitive. They becomes apparent with the increases of load rate. Nano metallic glass doesn’t have the serrated flow phenomenon that comes from uneven plastic.
Keywords  glass film,nano indenter, mechanical properties, creep, plastic deformation
目   录

1  绪论    5
1.1  纳米非晶材料    5
1.1.1 纳米级别非晶材料    6
1.2  纳米压痕实验    7
1.2.1 纳米压痕设备    7
1.2.2 纳米压痕测量原理    8
1.2.3 影响纳米压痕测量结果的因素    9
1.3  纳米压痕测量方向    9
1.3.1 硬度及弹性模量测量    9
1.3.2 蠕变性能测试    10
1.3.3 塑性变形和尺寸效应    11
1.3.4 应力硬化    12
2  实验方案与内容    14
2.1 方案和思路    14
2.2 纳米压痕仪操作    14
2.2.1 薄膜样品处理    14
2.2.2 制样    14
2.2.3 压痕操作    14
2.3 实验方案    15
2.3.1 硬度和弹性模量    15
2.3.2 小尺寸效应和塑性变形    15
2.3.3 蠕变性能    15
2.3.4 应力硬化    16
3  实验结果    17
3.1 NiP薄膜的硬度和弹性模量    17
3.2 压痕蠕变    20
3.3 尺寸效应    23
3.4 应变硬化    25
3.5 3D形貌扫描    26 纳米非晶材料的力学性能表征:http://www.youerw.com/cailiao/lunwen_13239.html
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