纳米金属材料制备..

zz = xz = yz =0
xx = ln （
yy
OA ）=lnR OA
OB ln( ) ln R OB
（R diagonal ratio）
zz + xz + yz =0
PSE
Shear strain components in PSE (切变应变分量)
xy =tan(
液中的金属离子
向阴极表面迁移 ，并沉积到阴极 表面，生成块体 金属纳米晶材料。
2、SPD法制备块体金属纳米材料
Pure shear
extrusion high pressure torsion equal channel
accumulative roll bonding repetitive corrugation
eq =
2 R2 1 2 2 eq = （lnR）R2 1 2 2 tot = （ln R) ( 2 ) R 1 3
PSE
Experimental procedure
Table 1 Chemical composition of the AA1050 alloy used in the study
固相法
通过机械研磨过 程粉粒进行反复 熔结、断裂，使
电沉积法
在浸入电解液的 阴、 阳极之间加 以电流，使电解
凝结为纳米尺度
的金属粉，在真 空中给金属纳米 粉加压、烧结一种工艺方法。
得粉粒不断细化
到纳米尺度，得 到纳米颗粒。然 后在经过压制。
Fig. 2.Shear strain states, (a) imposing shear stress, (b) pure shear and (c) simple shear condition.
PSE
Normal strain component in x and y directions

4
- )
xy
tan( )
l L
R2 1 2( 2 ) R 1
Equivalent strain
2 2 2 2 + 1 2 + 2 + 2 + + xx zz yy zz xz yz xx yy 3 xy 9
2
W and D are the side and diagonal of the initial square cross section and L and l are the long and short axes of the rhombic.
Fig 1.(a) Schematic illustration of pure shear extrusion, showing the ram in green color, the sample in red in zone I (the entry channel), the upper (zone II) and lower (zoneIII)deformation zones and the exit channel (zone IV) and (b) Top view of PSE deformation illustrating the changes of the cross section of the sample at the half course of PSE deformation.
The nanostructures of the PSEed samples were investigated using electron backscatter diffraction(EBSD电子背散射衍射).
PSE
Experimental result and discussion
It is clear that the microstructure of the as-rolled sample is composed of elongated grains formed during rolling. In order to dispose the effects of previous deformation steps on thefinal results of this investigation, the samples were fully annealed before PSE.
PSE
ARB
and straightening
angular extrusion
HPT
RCAS
multi-directional
forging
ECAE
MDF
SPD
severe plastic deformation （强塑性变形法）
Pure shear extrusion(PSE)
1 1 2 W L l= D 2 2
Fig.1.Microstructure of the sample in the (a) as-rolled and (b) as-annealed conditions.
PSE
Experimental result and discussion
strain components
Fig 5 Variations of strain components and equivalent strain with R.
Fig.3.Changes in the geometry of a small two-dimensional element (a) before PSE, squareABCD, (b) during the process, rhombic EFGHand (c) after PSE, rhombic.
块体金属纳米材料 结构性能
汇报人： 日期：2015.7.8
1
2
目录
块体金属纳米材料的制备方法
SPD法制备块体金属纳米材料
3 4
MD模型分析块体金属纳米材料特性
总结
1、块体金属纳米材料的制备方法
01
02
03
04
气相法
高真空反应室的 惰性气体保护下 加热金属，升华
液相法
它是在尽可能消 除异质核心的前 提下，使液态金