INFLUENCE OF SUBSTRATE TOPOGRAPHY ON THE NUCLEATION AND GROWTH OF 321 STAINLESS STEEL THIN FILMS PRODUCED BY MAGNETRON SPUTTERING

2008 ◽  
Vol 15 (04) ◽  
pp. 411-418 ◽  
Author(s):  
YONGZHONG JIN ◽  
DONGLIANG LIU ◽  
WEI WU ◽  
YALI SUN ◽  
ZUXIAO YU ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Magnetron Sputtering ◽  
Active Sites ◽  
Nucleation And Growth ◽  
Textured Surfaces ◽  
Force Microscopy ◽  
Substrate Topography ◽  
Atomic Force ◽  
Nucleation Sites ◽  
Influence Of Substrate

We have investigated the effects of substrate topography on the nucleation and growth behavior of 321 stainless steel (ss) films, introducing textured surfaces into mica substrates by the abrasion treatment. In this study, two groups of samples were prepared at three different sputtering time within 12 s using radio frequency (r.f.) magnetron sputtering and characterized by atomic force microscopy. Good nucleation uniformity has been obtained on the unabraded mica substrates due to the statistical distribution of nucleation sites. Especially, we have already observed an interesting unusual nucleation phenomenon, the island–rim structure on the abraded mica substrates after 4 s, where the island is fractal-like and the rim around the island was only occupied by few grains for nucleation. These ramified islands were located at the wide grooves introduced as predominate nucleation sites. The island–rim structure formed in initial nucleation process is closely associated with x, y velocity components of surface atoms and the distribution of active sites (related intimately to the surface free energy σ and strain energy ε) for nucleation. With the increasing of the sputtering time, voids and overlarge grains have been observed in the island–rim region after the sputtering time of 8 s and 12 s, respectively.

Micromechanisms of Hydrogen-Assisted Cracking in Super Duplex Stainless Steel Investigated by Scanning Probe Microscopy

2014 ◽  
Author(s):  
Bai An ◽  
Takashi Iijima ◽  
Chris San Marchi ◽  
Brian Somerday
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Scanning Tunneling ◽  
Super Duplex Stainless Steel ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Hydrogen Assisted Cracking ◽  
Cracking Mechanisms ◽  
Localized Plastic Deformation

Understanding the micromechanisms of hydrogen-assisted fracture in multiphase metals is of great scientific and engineering importance. By using a combination of scanning electron microscopy (SEM), scanning tunneling microscopy (STM), atomic force microscopy (AFM) and magnetic force microscopy (MFM), the micromorphology of fracture surface and microcrack formation in hydrogen-precharged super duplex stainless steel 2507 are characterized from microscale to nanoscale. The results reveal that the fracture surfaces consist of quasi-brittle facets with riverlike patterns at the microscale, which exhibit rough irregular patterns or remarkable quasi-periodic corrugation patterns at the nanoscale that can be correlated with highly localized plastic deformation. The microcracks preferentially initiate and propagate in ferrite phase and are stopped or deflected by the boundaries of the austenite phase. The hydrogen-assisted cracking mechanisms in super duplex stainless steel are discussed according to the experimental results and hydrogen-enhanced localized plasticity theory.

Investigation of surface morphology of thin metal films with magnetic layers Fe-Cr-Co

2021 ◽  
Author(s):  
V.S. Zayonchkovsky ◽  
Aung Kyaw Kyaw ◽  
A.V. Andreev
Keyword(s):  
Atomic Force Microscopy ◽  
Magnetron Sputtering ◽  
Electron Microscopic Examination ◽  
Nearest Neighbors ◽  
Substrate Plane ◽  
Large Area ◽  
Electron Microscopic ◽  
Force Microscopy ◽  
Atomic Force ◽  
Large Projection

Films containing layers of dispersion-hardening alloys (LDHA) based on the Fe-Cr-Co system were obtained by magnetron sputtering. LDHA acquire the properties of film permanent magnets after a single-stage «fast» high-vacuum annealing. Bulk materials acquire such properties only after many hours of multi-stage heat treatment. The film samples acquire these properties in tens of seconds. The morphology of their surface was studied to determine the origin of the coercive force of film samples. The surface morphology was studied using high resolution scanning electron microscopy and atomic force microscopy. We studied two compositions that, in bulk, have a different tendency to form many phases during crystallization. In magnetron sputtering, the alloy in which a multiphase state is easily formed is polycrystalline. The antipode alloy in magnetron sputtering is realized in an amorphous state. After annealing, both alloys are in a polycrystalline state. Electron microscopic examination showed that as a result of annealing, crystallites are formed with a large projection onto the substrate plane, which grow due to the nearest neighbors. Moreover, these crystallites have not only a large area, but also a height. After annealing, both alloys are in a polycrystalline state. Electron microscopic examination showed that as a result of annealing, crystallites are formed with a large projection onto the substrate plane, which grow due to the nearest neighbors. Moreover, these crystallites have not only a large area, but also a height. What is determined by atomic force microscopy. High crystallites are also faceted. This may indicate that the composition of these crystallites differs from the composition of the surrounding layer, which may be the reason for the increase in coercive force as a result of annealing.

Hydrogen Transport and Hydrogen-Assisted Cracking in SUS304 Stainless Steel During Deformation at Low Temperatures

2015 ◽  
Author(s):  
Lin Zhang ◽  
Bai An ◽  
Takashi Iijima ◽  
Chris San Marchi ◽  
Brian Somerday
Keyword(s):  
Stainless Steel ◽  
Hydrogen Embrittlement ◽  
Room Temperature ◽  
Hydrogen Release ◽  
Hydrogen Transport ◽  
Force Microscopy ◽  
Atomic Force ◽  
Strain Induced Martensite ◽  
Hydrogen Assisted Cracking ◽  
Slip Planes

The behaviors of hydrogen transport and hydrogen-assisted cracking in hydrogen-precharged SUS304 austenitic stainless steel sheets in a temperature range from 177 to 298 K are investigated by a combined tensile and hydrogen release experiment as well as magnetic force microscopy (MFM) based on atomic force microscopy (AFM). It is observed that the hydrogen embrittlement increases with decreasing temperature, reaches a maximum at around 218 K, and then decreases with further temperature decrease. The hydrogen release rate increases with increasing strain until fracture at room temperature but remains near zero level at and below 218 K except for some small distinct release peaks. The MFM observations reveal that fracture occurs at phase boundaries along slip planes at room temperature and twin boundaries at 218 K. The role of strain-induced martensite in the hydrogen transport and hydrogen embrittlement is discussed.

scholarly journals Structural and Morphological Properties of Titanium Aluminum Nitride Coatings Produced by Triode Magnetron Sputtering

2014 ◽  
Vol 10 (20) ◽  
pp. 51-64 ◽  
Author(s):  
D.M. Devia ◽  
E. Restrepo-Parra ◽  
J.M. Velez-Restrepo
Keyword(s):  
Magnetron Sputtering ◽  
Bias Voltage ◽  
Structural Changes ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Titanium Aluminum ◽  
Microscopy Techniques ◽  
Titanium Aluminum Nitride

Tix Al1−xN coatings were grown using the triode magnetron sputtering technique varying the bias voltage between -40 V and -150V. The influence of bias voltage on structural and morphological properties was analyzed by means of energy dispersive spectroscopy, x-ray diffraction and atomic force microscopy techniques. As the bias voltage increased, an increase inthe Al atomic percentage was observed competing with Ti and producing structural changes. At low Al concentrations, the film presented a FCC crystalline structure; nevertheless, as Al was increased, the structure pre-sented a mix of FCC and HCP phases. On the other hand, an increase inbias voltage produced a decrease films thickness due to an increase in colli-sions. Moreover, the grain size and roughness were also strongly influencedby bias voltage.

scholarly journals Nucleation and Growth of Supported Metal Clusters at Defect Sites on Mgo and NaCl (001) Surfaces: The Cases of Pd and Ag

1999 ◽  
Vol 570 ◽  
Author(s):  
J. A. Venables ◽  
G. Haas ◽  
H. Brune ◽  
J.H. Harding
Keyword(s):  
Deposition Temperature ◽  
Metal Clusters ◽  
Variable Temperature ◽  
Nucleation And Growth ◽  
Force Microscopy ◽  
Atomic Force ◽  
Defect Sites ◽  
Wide Range ◽  
Adsorption Surface

ABSTRACTNucleation and growth of metal clusters at defect sites is discussed in terms of rate equation models, which are applied to the cases of Pd and Ag on MgO(001) and NaCl(001) surfaces. Pd/MgO has been studied experimentally by variable temperature atomic force microscopy (AFM). The island density of Pd on Ar-cleaved surfaces was determined in-situ by AFM for a wide range of deposition temperature and flux, and stays constant over a remarkably wide range of parameters; for a particular flux, this plateau extends from 200 K ≤ T ≤ 600 K, but at higher temperatures the density decreases. The range of energies for defect trapping, adsorption, surface diffusion and pair binding are deduced, and compared with earlier data for Ag on NaCl, and with recent calculations for these metals on both NaCl and MgO

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