scholarly journals Effect of treatment time on characterization and properties of nanocrystalline surface layer in copper induced by surface mechanical attrition treatment

2014 ◽  
Vol 37 (5) ◽  
pp. 1087-1094 ◽  
Author(s):  
Farzad Kargar ◽  
M. Laleh ◽  
T. Shahrabi ◽  
A. Sabour Rouhaghdam
Keyword(s):  
Surface Layer ◽  
Treatment Time ◽  
Surface Mechanical Attrition Treatment ◽  
Mechanical Attrition ◽  
Effect Of Treatment

Surface Nanocrystallines of Fe3Al Produced by Surface Mechanical Attrition

2011 ◽  
Vol 320 ◽  
pp. 325-328 ◽  
Author(s):  
Jiang Wei Ren ◽  
Dong Li ◽  
Pei Quan Xu
Keyword(s):  
Grain Size ◽  
Surface Layer ◽  
Surface Mechanical Attrition Treatment ◽  
Electronic Microscopy ◽  
X Ray ◽  
Structure And Morphology ◽  
Mechanical Attrition ◽  
Deformed Layer ◽  
Fe3al Intermetallic ◽  
Morphology Of Surface

A nanocrystallines surface layer was produced in Fe3Al intermetallic compound by surface mechanical attrition treatment (SMAT). The microstructure of deformed layer, phase structure and morphology of surface nanocrystallines were characterized through optical microscopy, X-ray diffractometry, transmission electronic microscopy and high resolution electronic microscopy. The results show that a deformed layer about 11μm wide is produced after 10min surface mechanical attrition. The grains on the top surface of Fe3Al are refined to nanocrystallines and the grain size of nanocrystallines is about 35nm. High density dislocations collect on the boundaries of grains. The formation of nanocrystallines is controlled by grain subdivision mechanism.

Surface Nanocrystallization by Surface Mechanical Attrition Treatment

2008 ◽  
Vol 579 ◽  
pp. 91-108 ◽  
Author(s):  
N.R. Tao ◽  
Jian Lu ◽  
K. Lu
Keyword(s):  
Surface Layer ◽  
Grain Refinement ◽  
Mechanical Twinning ◽  
Surface Mechanical Attrition Treatment ◽  
Formation Mechanisms ◽  
Chemical Compositions ◽  
Tensile Fatigue ◽  
Mechanical Attrition ◽  
And Performance ◽  
Mechanical Twins

Based on strain-induced grain refinement, a novel surface mechanical attrition treatment (SMAT) technique has been developed to synthesize a nanostructured surface layer on metallic materials in order to upgrade their overall properties and performance without changing their chemical compositions. In recent several years, the microstructures and properties of surface layer were systematically investigated in various SMAT metals and alloys, including b.c.c., f.c.c. and h.c.p. crystal structures. Different grain refinement approaches and nanocrystalline formation mechanisms were identified in these deformed materials, involving dislocation activities, mechanical twinning and interaction of dislocations with mechanical twins. The properties of the surface layer were measured by means of hardness, tensile, fatigue and wear tests. The enhanced properties of the surface layer are mainly attributed to the strain-induced grain refinement. In this work, we reviewed the microstructures and properties of surface layer in the SMAT materials.

Interface Diffusion in Cu Processed by Means of Surface Mechanical Attrition Treatment

2009 ◽  
Vol 289-292 ◽  
pp. 557-563 ◽  
Author(s):  
Z.B. Wang ◽  
K. Wang ◽  
K. Lu ◽  
Gerhard Wilde ◽  
Sergiy V. Divinski
Keyword(s):  
Grain Size ◽  
Surface Layer ◽  
Subsurface Layer ◽  
Coarse Grained ◽  
Surface Mechanical Attrition Treatment ◽  
Nanostructured Surface ◽  
Radiotracer Technique ◽  
Mechanical Attrition ◽  
The Difference ◽  
Effective Diffusivities

A nanostructured surface layer with a gradient microstructure was produced on a Cu plate by means of the surface mechanical attrition treatment (SMAT). Diffusion of Ni in the nanostructured layer was investigated by the radiotracer technique at temperatures from 383 to 438 K. The measured diffusion profiles consist of two distinct sections with different slopes, the steep one corresponding to the top surface layer with the grain size of 10 to 25 nm and the shallow one corresponding to a subsurface layer with a grain size of 25 to 100 nm. The effective diffusivities derived from both sections are more than 2 orders of magnitudes higher than the grain boundary diffusivities in coarse-grained Cu. The significantly accelerated diffusion rates are expected to be associated with the “non-equilibrium” states of interfaces in the nanostructured surface layer induced by SMAT. The difference between the diffusivities in the top and sub- surface layer might result from the fact that most interfaces developed from twin boundaries in the former while produced by dislocation activities in the latter.

Study on the Structure and Properties of Surface Nanocrystallized Zr-4

2011 ◽  
Vol 415-417 ◽  
pp. 660-665
Author(s):  
Cong Hui Zhang ◽  
Da Li Liu ◽  
Xin Zhe Lan ◽  
Xi Cheng Zhao
Keyword(s):  
Surface Roughness ◽  
Surface Layer ◽  
Processing Time ◽  
Optical Microscope ◽  
Surface Mechanical Attrition Treatment ◽  
Structure And Properties ◽  
Nanostructured Surface ◽  
Grain Sizes ◽  
Mechanical Attrition ◽  
Average Grain Size

A nanostructured surface layer was obtained on the surface of Zr-4 by surface mechanical attrition treatment(SMAT). The structure and the properties of the SMAT sample were analyzed by means of the optical microscope, hardness and polarization curve testing. The results show that， when processing time for 5min, the average grain sizes on the surface layer can be refined to 23nm. The average grain size by SMAT-ed for 15min is 20nm, which is the smallest. The microhardness have a significant increase, the surface roughness also increase, and the corrosion resistance reduce in 1mol H2SO4solution.

Diffusion of Cr in Nanostructured Fe and Low Carbon Steel Produced by Means of Surface Mechanical Attrition Treatment

2006 ◽  
Vol 249 ◽  
pp. 147-154 ◽  
Author(s):  
Z.B. Wang ◽  
N.R. Tao ◽  
W.P. Tong ◽  
Jian Lu ◽  
K. Lu
Keyword(s):  
Surface Layer ◽  
Carbon Steel ◽  
Steel Plate ◽  
Low Carbon Steel ◽  
Coarse Grained ◽  
Surface Mechanical Attrition Treatment ◽  
Low Carbon ◽  
Triple Junctions ◽  
Exponential Factor ◽  
Mechanical Attrition

By means of surface mechanical attrition treatment (SMAT), nanostructured (NS) surface layers were fabricated on a pure iron plate and a low carbon steel plate. Cr diffusion behaviors in the NS Fe phase and the SMAT low carbon steel were investigated. Experimental results showed the activation energy of Cr diffusion in the NS Fe is comparable to that of the GB diffusion, but the pre-exponential factor is much higher. A much thicker Cr-diffusion surface layer was obtained in the SMAT low carbon steel plate than in the coarse-grained one after the same chromizing treatment. The much enhanced diffusivities of Cr in the SMAT samples can be attributed to numerous GBs and triple junctions with a high excess stored energy in the NS surface layer.

Mechanical Properties of 316L Stainless Steel with Nanostructure Surface Layer Induced by Surface Mechanical Attrition Treatment

2007 ◽  
Vol 353-358 ◽  
pp. 1810-1813 ◽  
Author(s):  
Xiao Hua Yang ◽  
Wei Zhen Dui ◽  
Gang Liu
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Wear Resistance ◽  
Surface Layer ◽  
316L Stainless Steel ◽  
Hardened Layer ◽  
Surface Mechanical Attrition Treatment ◽  
Mechanical Attrition ◽  
Nanostructure Surface ◽  
Nanocrystalline Layer

The mechanical properties of the 316L stainless steel subjected to surface mechanical attrition treatment (SMAT) have been studied, these properties are hardness, tensile properties and wear resistance. The research shows that the thickness of the hardened layer increases with the increasing of the treating time. The refined microstructure in the treated layer led to increasing in hardness, strength, and wear resistance. It is obvious that the surface layer hardness and bulk yield strength are increasing when the SMAT time reaches 5 minutes. The increase of surface layer wear resistance is obvious when the SMAT time is 15 minutes. The SEM observation of the wear scars shows that the nanocrystalline layer might reduce the effect of adhesive wear of 316L stainless steel. Therefore, the wear mechanism changes from adhesive abrasion to grinding particle abrasion after SMAT.

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