Ultra Fine Particle Films by Gas Deposition Method

1992 ◽  
Vol 286 ◽  
Author(s):  
Masaaki Oda ◽  
Isao Katsu ◽  
Michitaka Tsuneizumi ◽  
Eiji Fuchita ◽  
Seiichiro Kashu ◽  
...  
Keyword(s):  
Gas Flow ◽  
Fine Particles ◽  
Inorganic Materials ◽  
Deposition Method ◽  
Evaporation Chamber ◽  
Deposition Chamber ◽  
Evaporation Method ◽  
Gas Condensation ◽  
Ultra Fine Particle ◽  
Ultra Fine Particles

ABSTRACTUltra fine particles(UFP) of organic and inorganic materials can be formed by the gas evaporation method(gas condensation method). In the gas deposition method, particles formed by the gas evaporation method in an evaporation chamber are carried to another chamber (a deposition chamber) through a pipe. Particles are accelerated in the pipe with a gas flow and come out of a nozzle located in the deposition chamber which is being evacuated down to less than 10 torr and deposited on a substrate to form UFP films. The final speed of the particles depends on the pressure difference between the evaporation chamber and the deposition chamber. The particles speed exceeds 500m/s and adhesion strengths of the films reach 50OKgf/cm2 as well as vacuum deposition films in the condition that the pressure of the evaporation chamber is at 4 atms. Patterns of spots and lines with 50μm size and also wider films can be formed on a substrate without a masking system. The process is effective for repairing electric connecting lines or producing electrodes and condensers on an industrial scale.

Vaporization and Ultra-Fine Particle Generation during the Plasma Spraying Process

1997 ◽  
Author(s):  
K.A. Gross ◽  
P. Fauchais ◽  
M. Vardelle ◽  
J. Tikkanen ◽  
J. Keskinen
Keyword(s):  
Fine Particles ◽  
High Concentration ◽  
Thermal Spray Process ◽  
Particle Generation ◽  
Spray Process ◽  
Ultra Fine Particle ◽  
Fast Cooling ◽  
Ultra Fine Particles ◽  
Plasma Spraying Process ◽  
Very High

Abstract The thermal spray process melts powder at very high temperatures and propels the molten material to the substrate to produce a coherent deposit. This heating produces a certain amount of vaporization of the feedstock. Upon exiting the plasma plume the fast cooling conditions lead to condensation of the vapor. An electrical low pressure impactor was used to monitor the concentration of ultra-fine particles at various radial and axial distances. Metal, namely iron powder, showed very high concentration levels which increase with distance. Ultra-fine particles from ZrO2-8Y2O3 reached a peak concentration at 6 cm. Use of an air barrier during spraying decreases the population of ultra-fine particles facilitating the production of a stronger coating.

Studies of copper selenide ultrafine particles by newly developed gas evaporation method

1990 ◽  
Vol 48 (4) ◽  
pp. 306-307
Author(s):  
Chihiro Kaito ◽  
Yoshio Saito
Keyword(s):  
Crystal Structure ◽  
Ultrafine Particles ◽  
Fine Particles ◽  
Production Method ◽  
Atmospheric Temperature ◽  
Copper Selenide ◽  
Quartz Boat ◽  
Selenium Vapor ◽  
Ar Gas ◽  
Ultra Fine Particles

The direct evaporation of metallic oxides or sulfides does not always given the same compounds with starting material, i.e. decomposition took place. Since the controll of the sulfur or selenium vapors was difficult, a similar production method for oxide particles could not be used for preparation of such compounds in spite of increasing interest in the fields of material science, astrophysics and mineralogy. In the present paper, copper metal was evaporated from a molybdenum silicide heater which was proposed by us to produce the ultra-fine particles in reactive gas as shown schematically in Figure 1. Typical smoke by this method in Ar gas at a pressure of 13 kPa is shown in Figure 2. Since the temperature at a location of a few mm below the heater, maintained at 1400° C , were a few hundred degrees centigrade, the selenium powder in a quartz boat was evaporated at atmospheric temperature just below the heater. The copper vapor that evaporated from the heater was mixed with the stream of selenium vapor,and selenide was formed near the boat. If then condensed by rapid cooling due to the collision with inert gas, thus forming smoke similar to that from the metallic sulfide formation. Particles were collected and studied by a Hitachi H-800 electron microscope.Figure 3 shows typical EM images of the produced copper selenide particles. The morphology was different by the crystal structure, i.e. round shaped plate (CuSe;hexagona1 a=0.39,C=l.723 nm) ,definite shaped p1 ate(Cu5Se4;Orthorhombic;a=0.8227 , b=1.1982 , c=0.641 nm) and a tetrahedron(Cu1.8Se; cubic a=0.5739 nm). In the case of compound ultrafine particles there have been no observation for the particles of the tetrahedron shape. Since the crystal structure of Cu1.8Se is the anti-f1uorite structure, there has no polarity.

scholarly journals New Maskless Film Making Method Using Ultra Fine Particles.

Materia Japan ◽  
1995 ◽  
Vol 34 (4) ◽  
pp. 455-460 ◽  
Author(s):  
Eiji Fuchita ◽  
Masaaki Oda ◽  
Chikara Hayashi
Keyword(s):  
Fine Particles ◽  
Ultra Fine Particles ◽  
Film Making

Ultrafeine Partikel im Abgas von Humankremationsanlagen/Ultra-fine particles in the flue gas of human crematories

Gefahrstoffe ◽  
2020 ◽  
Vol 80 (01-02) ◽  
pp. 19-24 ◽  
Author(s):  
M. Köhler ◽  
A. Ohle ◽  
M. Beckmann ◽  
S. Steinau ◽  
F. Tettich ◽  
...  
Keyword(s):  
Flue Gas ◽  
Fine Particles ◽  
Ultra Fine Particles

Der Anteil an Kremationen (Feuerbestattungen) nimmt in Deutschland seit Jahren zu und umfasst bereits mehr als 65 % aller Bestattungen. Grenzwerte für die Emissionen von Feinstaub oder die Anzahl ultrafeiner Partikel (UFP) existieren nicht und bisher sind auch keine systematischen Untersuchungen bekannt, welche Partikelemissionen in Krematorien auftreten. Daher kann zum aktuellen Zeitpunkt nicht beurteilt werden, ob es sich bei Krematorien um nennenswerte Feinstaubquellen handelt. Um diese Lücke zu schließen, wurden die reingasseitigen UFP-Konzentrationen in zehn Krematorien unterschiedlichen Bau- bzw. Modernisierungsjahres und mit verschiedenen Abgasreinigungstechnologien gemessen. Über die Kremationsdauer gemittelte UFP-Konzentrationen zwischen 1,19 · 10³ und 4,26 · 107 cm–3 wurden erfasst. Die höchsten Konzentrationen zeigten sich bei Anlagen mit Flugstromverfahren, deren Filtereinheiten unmittelbar vor der nächsten Revision standen. Bei Anlagen gleichen Typs mit gewarteten Filtereinheiten lag die mittlere UFP-Konzentration zwei Größenordnungen darunter.

scholarly journals Welding, Bonding, Brazing. Part II. Titanium Brazing with Ultra Fine Particles.

Shinku ◽  
1996 ◽  
Vol 39 (6) ◽  
pp. 302-305
Author(s):  
Seiichirou KASHU ◽  
Yasuo MIHARA ◽  
Chikara HAYASHI
Keyword(s):  
Fine Particles ◽  
Ultra Fine Particles

Gas anti-solvent recrystallization of RDX: Formation of ultra-fine particles of a difficult-to-comminute explosive

1992 ◽  
Vol 5 (2) ◽  
pp. 130-142 ◽  
Author(s):  
Paula M. Gallagher ◽  
M.P. Coffey ◽  
V.J. Krukonis ◽  
W.W. Hillstrom
Keyword(s):  
Fine Particles ◽  
Ultra Fine Particles

scholarly journals Production Technique of Ultra-fine Particles of Titanium by Pulse YAG Laser.

1995 ◽  
Vol 42 (10) ◽  
pp. 1184-1189
Author(s):  
Ryoji Okada ◽  
Mitsuaki Haneda ◽  
Susumu Hioki ◽  
Takeshi Araya ◽  
Akira Matsunawa ◽  
...  
Keyword(s):  
Fine Particles ◽  
Production Technique ◽  
Yag Laser ◽  
Ultra Fine Particles
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