Intermetallic Coating Using a 3-Dimensional Micro Welder

2009 ◽  
Vol 631-632 ◽  
pp. 259-264
Author(s):  
Kiyotaka Matsuura ◽  
Naoki Mizuta ◽  
Soshu Kirihara ◽  
Yoshinari Miyamoto ◽  
Atsushi Yumoto
Keyword(s):  
Titanium Aluminides ◽  
Substrate Surface ◽  
Titanium Substrate ◽  
Coated Sample ◽  
Process Conditions ◽  
Aluminum Wire ◽  
3 Dimensional ◽  
Intermetallic Coating ◽  
Wire Feeding ◽  
Thin Metal Wire

The authors have studied a new method of intermetallic coating using a small TIG welder. This method is based on a reaction between small liquid beads produced from very thin metal wire and the substrate metal surface. The authors designed a computer-aided 3-dimensional micro welder (3DMW) for a previous study on freeform fabrication of intermetallics, and have applied it to this study on intermetallic coating. In this study, a predetermined length of thin aluminum wire was fed onto the titanium substrate surface, and a spark was stricken from a thin electrode of a W-Ce2O3 alloy to make a small aluminum liquid bead on the titanium substrate surface and to simultaneously melt a small area of the substrate surface beneath the liquid bead. All process conditions had been programmed beforehand, including the length of the wire feeding per spark, the position of the electrode, electric power, movement of the stage holding the substrate, etc. The liquid bead containing aluminum and titanium rapidly solidified on the titanium substrate surface producing titanium aluminides on it. Repetition of the aluminum wire feeding, the electrode positioning and the spark striking produced a coating layer consisting of sub-layers of TiAl3, TiAl and Ti3Al from the surface side to the substrate side. Vickers hardness and wear resistance of the coated sample were remarkably improved.

In situ ATR - FTIR spectroscopy of Hf(IV) tert butoxide adsorption on Si and Ge

2006 ◽  
Vol 917 ◽  
Author(s):  
Shilpa Dubey ◽  
Keijing Li ◽  
Harish Bhandari ◽  
Zheng Hu ◽  
C. Heath Turner ◽  
...  
Keyword(s):  
Hafnium Oxide ◽  
Density Functional ◽  
Substrate Surface ◽  
Surface Concentration ◽  
Bidentate Ligand ◽  
Initial Reaction ◽  
Process Conditions ◽  
Reaction Cell

AbstractHafnium oxide ultra thin films on Si (100) are being developed to replace thermally grown SiO2 gates in CMOS devices. In this work, a specially designed Attenuated Total Reflectance - Fourier Transform Infra Red Spectroscopy (ATR-FTIR) reaction cell has been developed to observe chemisorption of hafnium (IV) t-butoxide onto a Si and Ge ATR crystal heated up to 250°C and under 1 torr of vacuum to observe the initial reaction pathways and species on the substrate surface in real time and under typical process conditions. Chemisorption spectra were compared to spectra of the liquid precursor and to spectra generated by density functional theory (DFT) calculations of liquid, monodentate and bidentate absorbed precursor. An asymmetric stretching mode located at ~1017 cm-1 present in the chemisorbed spectra but not in the liquid spectra indicates that the adsorbed hafnium containing group is prevalent as a bidentate ligand according to calculations. Surface concentration of the chemisorbed species was dependant on the substrate temperature and precursor partial pressure allowing for determination of heats of adsorption which was 26.5 kJ/mol on Si.

A 3-Dimensional Temperature Uniformity Model for a Rapid Thermal Processing Furnace

1994 ◽  
Vol 342 ◽  
Author(s):  
R. Henda ◽  
E. Scheid ◽  
D. Bielle-Daspet
Keyword(s):  
Thermal Processing ◽  
Three Dimensional ◽  
Wafer Surface ◽  
Process Conditions ◽  
Dimensional Model ◽  
Radiation Heat ◽  
Three Dimensional Model ◽  
3 Dimensional ◽  
Component Models ◽  
System Geometry

ABSTRACTA fully three dimensional model has been developed for simulating the thermal behaviour of a RTP furnace. This model consists of two components to achieve the whole analysis. The first component models the radiation heat flux density at the wafer surface as a function of the system geometry, the lamp position and intensity, and the wall reflectivities. The second component solves the heat conduction equation at each point within the wafer using appropriate boundary conditions, including convective cooling which effect depends on the process conditions. A particular attempt is made upon the achievement of a flat temperature profile over the wafer by investigating the system parameters in order to improve the RTP equipement.

Constituent Particles and Dispersoids in an Al-Mn-Fe-Si Alloy Studied in Three-Dimensions by Serial Sectioning

2013 ◽  
Vol 765 ◽  
pp. 451-455 ◽  
Author(s):  
Liam Dwyer ◽  
Joseph Robson ◽  
Joao Quinta da Fonseca ◽  
Nicolas Kamp ◽  
Teruo Hashimoto ◽  
...  
Keyword(s):  
Accurate Determination ◽  
Three Dimensions ◽  
Process Conditions ◽  
Second Phase ◽  
Serial Sectioning ◽  
3 Dimensional ◽  
Intermetallic Particles ◽  
Second Phase Particles ◽  
Proper Consideration

Second phase particles in wrought aluminium alloys are crucial in controlling recrystallization and texture. In Al-Mn-Fe-Si (3xxx) alloys, the size, spacing, and distribution of both large constituent particles and small dispersoids are manipulated by heat treatment to obtain the required final microstructure and texture for operations such as can-making. Understanding how these particles evolve as a function of process conditions is thus critical to optimize alloy performance. In this study, a novel 3-dimensional technique involving serial sectioning in the scanning electron microscope (SEM) has been used to analyse the intermetallic particles found in an as-cast and homogenized Al-Mn-Fe-Si alloy. This has allowed an accurate determination of the size and shape of the constituent particles and dispersoids derived from a 3-dimensional dataset. It is demonstrated that a proper consideration of the 3-dimensional microstructure reveals important features that are not obvious from 2-dimensional sections alone.

scholarly journals Derivation of Appropriate Conditions for Additive Manufacturing Technology Using Hot-Wire Laser Method

2021 ◽  
Vol 3 (1) ◽  
pp. 9
Author(s):  
Song Zhu ◽  
You Nakahara ◽  
Hideki Aono ◽  
Ryo Ejima ◽  
Motomichi Yamamoto
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Technology ◽  
Process Conditions ◽  
In Situ Observation ◽  
Maximum Height ◽  
Hot Wire ◽  
Laser Method ◽  
Additive Manufacturing Technology ◽  
Wire Feeding ◽  
Process Speed

The aim of this research was to develop a high-efficiency and high-material-use additive manufacturing technology using the hot-wire laser method. In this study, the optimization of process conditions using a combination of a high-power diode laser with a relatively large rectangular laser spot and a hot-wire system was investigated. The effects of process parameters such as laser power, process speed, and wire feeding rate (wire feeding speed/process speed) on a bead appearance and cross-sectional characteristics (e.g., effective width, effective height, maximum height, and near net shape rate) were studied in detail. The process phenomena during the multi-layer deposition were investigated by in situ observation via a high-speed camera.

Multiphysics Modeling and Simulation of an Arc-Jet Sprayer

2021 ◽  
Author(s):  
Juan J. Campos Manzo ◽  
Nicole Wagner ◽  
Kevin R. Anderson
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Substrate Surface ◽  
Arc Spraying ◽  
Process Conditions ◽  
Transfer Model ◽  
Ansys Fluent ◽  
Numerical Heat Transfer ◽  
Twin Wire Arc Spraying ◽  
Wire Arc Spraying

Abstract Twin wire arc spraying (TWAS) is a plasma spraying process that offers low workpiece heating and high deposition rates at a lower cost. Variations in TWAS process conditions cause the substrate temperature to fluctuate and even melt. Therefore, the motivation of this project was to simulate the heat transfer from the TWAS torch to the substrate during spraying and layer formation of a coating. Simulations using ANSYS FLUENT Computational Fluid Dynamics (CFD) software were used to model the heat transfer in a TWAS system. The results of this paper are meant to augment and improve the database of TWAS technology. A CFD numerical heat transfer model is presented that was used to investigate the substrate surface temperature during the TWAS process. The results for the different pressure models showed that for a 3 second simulation, substrate surface temperatures increased as nozzle inlet pressure was decreased. For the upper and lower bound pressures of 75 psia and 29 psia, substrate surface temperature resulted in 946 °C and 1010 °C, respectively.

Surface Treatment and Layer Structure in 2H-GaN Grown on the (0001)Si surface of 6H-SiC by MBE

1997 ◽  
Vol 2 ◽  
Author(s):  
P. Ruterana ◽  
Philippe Vermaut ◽  
G. Nouet ◽  
A. Salvador ◽  
H. Morkoç
Keyword(s):  
Surface Treatment ◽  
Defect Density ◽  
Layer Structure ◽  
Substrate Surface ◽  
Misfit Dislocations ◽  
Island Growth ◽  
3 Dimensional ◽  
Order Of Magnitude ◽  
Dimensional Growth ◽  
Substrate Annealing

Heteroepitaxy of hexagonal symmetry materials is more complicated than in the more usual case of cubic systems. In the growth of layers on the (0001) surfaces, the misfit dislocations always exhibit a screw component that leads to rotation of the epilayer in a 3 dimensional growth mode. The size of the islands will depend on many factors among which the substrate surface treatment, prior to growth, may be a predominant one. In this work, a comparative study is carried out for samples grown on plasma treated samples, with and without additional substrate annealing prior to epitaxy. It is found that the defect density can be brought below 109 cm−2, which is better than one order of magnitude in comparison to the layers grown on sapphire substrates. On top of the annealed substrates, the island growth is not obvious. Whereas, misorientations as large as a few degrees can be measured inside the layers on top of non annealed substrates, justifying the occurrence of high densities of threading dislocations.

Hard Coating is Because of Oppositely Worked Force-Energy Behaviors of Atoms

2018 ◽  
Author(s):  
Mubarak Ali ◽  
Esah Hamzah ◽  
Mohd Radzi Mohd Toff
Keyword(s):  
Potential Energy ◽  
Protective Coatings ◽  
Substrate Surface ◽  
Input Power ◽  
Hard Coatings ◽  
Surgical Instruments ◽  
Hard Coating ◽  
Outer Ring ◽  
Process Conditions ◽  
Electron Level

Coatings of suitable materials having thickness of few atoms to several microns on the viable substrates are the basic need of society and they attend the regular attention of scientific community working in various fields of science and technology. Decorative and protective coatings, transparent and insulating coatings, coatings of medical implants and surgical instruments, coatings for drug delivery and security purposes, ultra-precision machine coatings and coatings of miscellaneous uses are in the routine demand of research and commercial objectives. Different hard coatings develop under the significant composition of differently natured atoms where their force-energy behaviors as per recovering of transition states provide the provision for electron (of outer ring) belonging to gas atom to undertake another clamp of unfilled energy knot (of outer ring) belonging to solid atom. Set process conditions switch force-energy behaviors of differently natured atoms as per set process conditions where they worked differently to the original state behaviors. Different natured atoms develop structure in the form of hard coating by locating the ground point between original points where gas atoms increase potential energy under the decreasing levitational force at electron-level while the solid atoms decrease potential energy under the decreasing gravitational force at electron-level. Ti-atom to Ti-atom binding is through the difference of expansion of their lattices when one atom is just landing on the already appropriately landed atom where the adhered nitrogen atoms come nearly at their interstitial sites. Under suitable set parameters, different natured atoms deposit in the form of coating at substrate surface under the given conditions depending on the source-behavior of their ejecting or dissociating associated to employed technique. In random arc-based vapor deposition system, depositing different natured atoms at substrate surface depends on the input power where involved non-conserved energies engaged the non-conservative forces to keep their structure adhered. Different properties and characteristics of hard coatings emerged as per engaged forces under the set conditions of involved energy. The present study sets new trends not only in the field of coatings but also in the diversified class of materials and their counterparts, wherever, atoms recall their roles.

Hydroxyapatite Coating on Thermal Titanium Substrate in Aqueous Solution

1999 ◽  
Vol 599 ◽  
Author(s):  
M. Okido ◽  
R. Ichino ◽  
K. Kuroda ◽  
R. Ohsawa ◽  
O. Takai
Keyword(s):  
Aqueous Solution ◽  
Induction Heating ◽  
Ambient Pressure ◽  
Substrate Surface ◽  
Titanium Substrate ◽  
Current Method ◽  
Heating Time ◽  
Fluoride Ions ◽  
Substrate Heating ◽  
Alternative Current

AbstractA hydroxyapatite, HAP, film was deposited on a titanium substrate in an aqueous solution, at an ambient temperature and ambient pressure. The solution included 3 mmoldm-3 Ca(H2PO4)2 and 7 mmol dm-3 CaCl2 at pH 5.5. The temperature of the substrate surface was controlled in both methods of applying alternative current through the Ti foil and high frequency induction heating using Ti ingot. In these methods, the substrate was heated up and the temperature gradient was formed between the substrate and the solution. The effects of surface temperature, fluoride ions, additive inhibitor and heating time on the morphology of HAP crystals formed on Ti substrate were investigated in various conditions. The morphology changed from compact layer to dendrite layer with the HAP growing time in AC current method and the HAP film with the thickness of 200 μm can be obtained on Ti foil with cross section of 30 μm × 2mm by heating for 20 min at 20 A-AC. On the other hand, the deposits consisted of algae-like whisker in the induction heating method. The HAP formation is found to take place only on the substrate surface by these substrate heating methods without HAP precipitation in aqueous solution

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