scholarly journals The effect of RF-DC plasma N2-H2 in the selective hardening process for micro-patterned AISI420

2019 ◽  
Author(s):  
Hengky Herdianto ◽  
Dionisius Johanes Djoko Herry Santjojo ◽  
Masruroh
Keyword(s):  
Substrate Surface ◽  
Molecular Ions ◽  
Hardness Profile ◽  
High Nitrogen ◽  
Dc Plasma ◽  
Surface Areas ◽  
Nano Carbon ◽  
Carbon Mapping ◽  
Two Peaks ◽  
Maskless Patterning

The high density of RF-DC plasma N2-H2 was used to make precise micro-texturing onto AISI420 has complex textured geometry. The original 2D micro-patterns were drawn onto substrate surface by maskless patterning using by of nano-carbon ink. These micro-patterned specimens were further plasma-nitrided at 673 K for 5.4 ks by 70 Pa using the hollow cathode device. The emissive light spectroscopy shows species in plasma were nitrogen atoms together with NH radicals and nitrogen molecular ions. Unprinted surface areas had selectively nitrided, have high nitrogen solute contents up to 12 mass%. Masked area just corresponded to carbon-mapping from printed nano-carbon inks, while unprinted surface to nitrogen mapping. The hardness profile had stepwise change across the borders between these printed and unprinted areas; e.g., the hardness on unprinted surface was 1200 Hv while it remained to be 350 Hv on printed surface. This selective nitriding and hardening enabled to construct the 3D textured miniature dies and products by chemical etching of printed area. These two peaks were related to extended martensitic lattice by high nitrogen extraordinary solid solution. The phase transformation from martensitic lattice α’-Fe through expanded phase into ε-Fe3N lattice.

scholarly journals PRECISE COMPLEX MICRO-TEXTURING INTO STAINLESS STEELS BY PLASMA PRINTING

2019 ◽  
Author(s):  
Hengky Herdianto ◽  
Tatsuhiko Aizawa ◽  
Kenji Wasa ◽  
Dionisius Johanes Djoko Herry Santjojo ◽  
Setyawan Purnomo Sakti
Keyword(s):  
Stainless Steels ◽  
Substrate Surface ◽  
Hardness Profile ◽  
High Nitrogen ◽  
Surface Areas ◽  
Nano Carbon ◽  
Carbon Mapping ◽  
Maskless Patterning ◽  
Carbon Inks ◽  
Micro Patterns

The plasma printing was used to make precise micro-texturing into the stainless steels to have complex textured geometry. First in this plasma printing, the original two dimensional micro-patterns were drawn onto the substrate surface by the maskless patterning with use of the nano-carbon ink. These micro-patterned specimens were further plasma-nitrided at 673 K for 5.4 ks by 70 Pa with use of the hollow cathode device. The unprinted surface areas were selectively nitrided to have high nitrogen solute contents up to 12 mass%. The masked area just corresponded to the carbon-mapping from the printed nano-carbon inks, while the unprinted surface, to the nitrogen mapping. The hardness profile had stepwise change across the borders between these printed and unprinted areas; e.g., the hardness on the unprinted surface was 1200 Hv while it remained to be 350 Hv on the printed surface. This selective nitriding accompanied with the selective hardening. This selective nitriding enabled us to construct the three dimensionally textured miniature dies and products by chemical etching of the printed area.

scholarly journals Optimization of process parameters in the RF-DC plasma N2-H2 for AISI420 molds and dies

2019 ◽  
Author(s):  
Hengky Herdianto ◽  
Dionisius Johanes Djoko Herry Santjojo ◽  
Masruroh
Keyword(s):  
Process Parameters ◽  
Substrate Surface ◽  
Xrd Analysis ◽  
Iron Nitrides ◽  
Dc Plasma ◽  
Precision Forging ◽  
Optimization Of Process Parameters ◽  
Dc Bias ◽  
Substrate Surfaces

The RF-DC plasma N2-H2 was used to make precise AISI420 molds and dies have complex textured geometry. The quality of the molds and dies directly affect the quality of the produced parts. The excellent examples of molds were used for injection molding lenses and dies used for the precision forging of automotive drive train components. In this study, a temperature, DC bias, and duration as process parameters of the RF-DC plasma N2-H2 have been optimized for molds and dies fabrication. The mask-less micro-patterned method was utilized to draw the initial 2D micro patterns directly onto the AISI420 substrate surface. The unprinted substrate surfaces were selectively nitrided by the RF-DC plasma N2-H2 at 673 K for 5400 s by 70 Pa with hollow cathode device. Energy Dispersive X-ray was utilized to describe the nitrogen content distribution at the vicinity of the border between the unprinted surfaces. This exclusive nitrogen mapping proves that only the unprinted parts of the substrate have high content nitrogen solutes. XRD analysis was performed to investigate whether the iron nitrides were precipitated by RF-DC plasma N2-H2 in the AISI420.

Plasma Printing of Micronozzles With Complex Shaped Outlets Into Stainless Steel Sheets

2019 ◽  
Vol 7 (3) ◽  
Author(s):  
Tatsuhiko Aizawa ◽  
Kenji Wasa
Keyword(s):  
Stainless Steel ◽  
Stainless Steel Substrate ◽  
Steel Substrate ◽  
Substrate Surface ◽  
Maskless Lithography ◽  
Two Dimensional ◽  
Nitrogen Diffusion ◽  
High Nitrogen ◽  
Steel Sheets ◽  
Inner Diameter

Abstract The plasma printing was developed as a means to fabricate the micronozzle chip with the inner diameter less than 50 μm. The initial two-dimensional micropattern was printed onto the stainless steel substrate surface by the maskless lithography. These printed micropatterns were utilized as a mask to make selective nitriding into the unprinted surface. After removal of printed pattern, the un-nitrided surfaces were chemically etched to leave the nitrided microtexture as a micronozzle chip. High nitrogen supersaturation as well as selective nitrogen diffusion had influence on the spatial resolution in this plasma printing in addition to the digitizing error in the maskless lithography.

Characterization of Diamond Spherical Shell Thick Film by DC Plasma CVD

2008 ◽  
Vol 375-376 ◽  
pp. 216-220 ◽  
Author(s):  
Duo Sheng Li ◽  
Dun Wen Zuo ◽  
Yu Li Sun ◽  
Rong Fa Chen ◽  
Wen Zhuang Lu ◽  
...  
Keyword(s):  
Spherical Shell ◽  
Thick Film ◽  
Diamond Film ◽  
Substrate Surface ◽  
Film Surface ◽  
Growth Surface ◽  
Dc Plasma ◽  
Force Microscopy ◽  
Microstructure Morphology

Diamond spherical shell thick film was prepared by high power DC-plasma jet CVD. Atom force microscopy, scanning electron microscopy, Raman spectroscopy and roughness-profile-meter were used to characterize microstructure, morphology, impurities and orientation evolution of diamond spherical shell thick film. The results show that, when nucleation begins, grains grow random orientation. The grain size of spherical diamond film prepared is compact, clear, uniform, continuous and no remarkable bigger grain over the whole surface of film. On the growth surface, (100) facets were dominant, and the cross-section SEM indicated that film columnar spreading grew from the substrate surface to the diamond film surface. The roughness of the growth surface was much more than that of the nucleation surface. To adjust some important parameters as methane concentrate, depositing time, and matrix temperature, and high quality diamond spherical shell thick film was deposited.

scholarly journals Незаполненные электронные состояния и потенциальный барьер в пленках замещенных дифенилфталидов на поверхности высокоупорядоченного пиролитического графита

2021 ◽  
Vol 63 (2) ◽  
pp. 299
Author(s):  
А.С. Комолов ◽  
Э.Ф. Лазнева ◽  
Н.Б. Герасимова ◽  
В.С. Соболев ◽  
С.А. Пшеничнюк ◽  
...  
Keyword(s):  
Energy Range ◽  
Work Function ◽  
Potential Barrier ◽  
Substrate Surface ◽  
Pyrolytic Graphite ◽  
Electronic States ◽  
Organic Films ◽  
Total Current ◽  
Electronic Work Function ◽  
Two Peaks

The results of a study of the unoccupied electronic states of ultrathin films of bis-carboxyphenyl-phthalide (DCA-DPP) and bis-methylphenyl-phthalide (DM-DPP) up to 8 nm thick are presented. The studies were carried out by total current spectroscopy (TCS) technique in the energy range from 5 eV to 20 eV above EF during thermal vacuum deposition of these organic films on the surface of highly oriented pyrolytic graphite (HOPG). The energy Evac relative to EF, that is, the electronic work function of the DM-DPP films, at a film thickness of 5–8 nm was 4.3 ± 0.1 eV. The electronic work function of the DCA-DPP films was 3.7 ± 0.1 eV. The structure of the maxima of the unoccupied electronic states of DCA-DPP films and DM-DPP films in the studied energy range is determined. The properties determined of DCA-DPP and DM-DPP films are compared with the properties of films of unsubstituted diphenylphthalide (DPP). According to our analysis, –CH3 substitution of the DPP molecule practically did not affect the height of the potential barrier between the film and the HOPG surface, and –COOH substitution of the DPP molecule led to an increase in the height of the potential barrier between the film and the HOPG substrate surface by 0.5–0.6 eV. Substitution of DPP molecules with –COOH functional groups which represents formation of DCA-DPP molecules led to a shift of two peaks of the experimental total current spectra located at energies in the range from 5 eV to 8 eV above EF, by about 1 eV towards lower electron energies.

Mesoporous nitrogen-doped carbons with high nitrogen contents and ultrahigh surface areas: synthesis and applications in catalysis

2016 ◽  
Vol 18 (7) ◽  
pp. 1976-1982 ◽  
Author(s):  
Zhishuang Ma ◽  
Hongye Zhang ◽  
Zhenzhen Yang ◽  
Guipeng Ji ◽  
Bo Yu ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Aqueous Phase ◽  
High Efficiency ◽  
High Nitrogen Content ◽  
High Nitrogen ◽  
Nitrogen Doped ◽  
Surface Areas ◽  
Nitrogen Contents

Mesoporous nitrogen-doped carbons with high nitrogen content and ultrahigh surface areas were prepared, which showed high efficiency for oxidation of alkanes in aqueous phase.

Facile synthesis of nitrogen-doped unzipped carbon nanotubes and their electrochemical properties

RSC Advances ◽  
2015 ◽  
Vol 5 (11) ◽  
pp. 8175-8181 ◽  
Author(s):  
Liang Chen ◽  
Haihui Zhou ◽  
Shudan Wei ◽  
Zhongxue Chen ◽  
Zheng Huang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrochemical Properties ◽  
Nitrogen Level ◽  
High Nitrogen ◽  
Facile Synthesis ◽  
Nitrogen Doped ◽  
Surface Areas ◽  
Good Crystallinity ◽  
High Nitrogen Level

N-UCNTs with a high nitrogen level, large surface areas and good crystallinity are synthesized by pyrolysis of an O-UCNTs/melamine composite.

Energetic Decomposition of High-Nitrogen Metal Complexes and the Formation of Low-Density Nano-Structured Metal Monoliths

2005 ◽  
Vol 896 ◽  
Author(s):  
Bryce C Tappan ◽  
My Hang Huynh ◽  
Michael A. Hiskey ◽  
David E. Chavez ◽  
Erik P. Luther ◽  
...  
Keyword(s):  
Metal Complexes ◽  
High Surface ◽  
Porous Metal ◽  
Low Density ◽  
High Nitrogen ◽  
Nitrogen Ligand ◽  
Surface Areas ◽  
Pressure Dependency ◽  
Dynamic Assembly ◽  
Combustion Synthesis Technique

AbstractMetal complexes of the energetic high-nitrogen ligand, bistetrazole amine (BTA) were ignited in inert environments and their decomposition characteristics were determined. These molecules were found to have the unique properties of a comparatively slow burning rate with very little pressure dependency, unlike most energetic, metal-containing molecules which tend to detonate, rather than burn steadily. This process resulted in unprecedented ultra-low-density, nano-structured, transition metal monoliths, useful as a self-propagating combustion synthesis technique. The resulting nanostructured metal monolithic foams formed in the post flame-front dynamic assembly have remarkably low densities down to 0.011 g cm-3 and extremely high surface areas as high as 270 m2 g-1. In this work we discuss primary the production of iron monoliths, however have produced monolithic nano-porous metal foams via this method with cobalt, copper and silver metals as well. We expect to be able to apply this to many other metals and to be able to tailor the resulting structure significantly.

scholarly journals Controlled graphene oxide assembly on silver nanocube monolayers for SERS detection: dependence on nanocube packing procedure

2016 ◽  
Vol 7 ◽  
pp. 9-21 ◽  
Author(s):  
Martina Banchelli ◽  
Bruno Tiribilli ◽  
Roberto Pini ◽  
Luigi Dei ◽  
Paolo Matteini ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Substrate Surface ◽  
Surface Enhanced Raman Spectroscopy ◽  
Silver Nanostructures ◽  
Langmuir Blodgett ◽  
Sers Enhancement ◽  
Surface Areas ◽  
Silver Nanocubes ◽  
Surface Enhanced Raman ◽  
Langmuir Blodgett Films

Hybrid graphene oxide/silver nanocubes (GO/AgNCs) arrays for surface-enhanced Raman spectroscopy (SERS) applications were prepared by means of two procedures differing for the method used in the assembly of the silver nanocubes onto the surface: Langmuir–Blodgett (LB) transfer and direct sequential physisorption of silver nanocubes (AgNCs). Adsorption of graphene oxide (GO) flakes on the AgNC assemblies obtained with both procedures was monitored by quartz crystal microbalance (QCM) technique as a function of GO bulk concentration. The experiment provided values of the adsorbed GO mass on the AgNC array and the GO saturation limit as well as the thickness and the viscoelastic properties of the GO film. Atomic force microscopy (AFM) measurements of the resulting samples revealed that a similar surface coverage was achieved with both procedures but with a different distribution of silver nanoparticles. In the GO covered LB film, the AgNC distribution is characterized by densely packed regions alternating with empty surface areas. On the other hand, AgNCs are more homogeneously dispersed over the entire sensor surface when the nanocubes spontaneously adsorb from solution. In this case, the assembly results in less-packed silver nanostructures with higher inter-cube distance. For the two assembled substrates, AFM of silver nanocubes layers fully covered with GO revealed the presence of a homogeneous, flexible and smooth GO sheet folding over the silver nanocubes and extending onto the bare surface. Preliminary SERS experiments on adenine showed a higher SERS enhancement factor for GO on Langmuir–Blodgett films of AgNCs with respect to bare AgNC systems. Conversely, poor SERS enhancement for adenine resulted for GO-covered AgNCs obtained by spontaneous adsorption. This indicated that the assembly and packing of AgNCs obtained in this way, although more homogeneous over the substrate surface, is not as effective for SERS analysis.

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