Preparation of binder‐free spherical submicron‐sized platinum particles using laser melting in liquids

2021 ◽  
Vol 104 (4) ◽  
Author(s):  
Takeshi Tsuji ◽  
Yuuta Suzuki ◽  
Shota Sakaki ◽  
Yoshie Ishikawa ◽  
Naoto Koshizaki
Keyword(s):  
Laser Melting ◽  
Platinum Particles ◽  
Binder Free

Preparation of Binder-Free Spherical Submicron-Sized Platinum Particles Using Laser Melting in Liquids

2021 ◽  
Vol 141 (7) ◽  
pp. 755-760
Author(s):  
Takeshi Tsuji ◽  
Yuuta Suzuki ◽  
Shota Sakaki ◽  
Yoshie Ishikawa ◽  
Naoto Koshizaki
Keyword(s):  
Laser Melting ◽  
Platinum Particles ◽  
Binder Free

Microstructural characterization of laser-melted/roller-quenched dicalcium silicate

1988 ◽  
Vol 46 ◽  
pp. 582-583
Author(s):  
C. J. Chan ◽  
K. R. Venkatachari ◽  
W. M. Kriven ◽  
J. F. Young
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Shape Change ◽  
Microstructural Characterization ◽  
Particle Size Effect ◽  
Dicalcium Silicate ◽  
Laser Melting ◽  
Uniform Size ◽  
Cell Shape Change ◽  
Wide Range

Dicalcium silicate (Ca2SiO4) is a major component of Portland cement. It has also been investigated as a potential transformation toughener alternative to zirconia. It has five polymorphs: α, α'H, α'L, β and γ. Of interest is the β-to-γ transformation on cooling at about 490°C. This transformation, accompanied by a 12% volume increase and a 4.6° unit cell shape change, is analogous to the tetragonal-to-monoclinic transformation in zirconia. Due to the processing methods used, previous studies into the particle size effect were limited by a wide range of particle size distribution. In an attempt to obtain a more uniform size, a fast quench rate involving a laser-melting/roller-quenching technique was investigated.The laser-melting/roller-quenching experiment used precompacted bars of stoichiometric γ-Ca2SiO4 powder, which were synthesized from AR grade CaCO3 and SiO2xH2O. The raw materials were mixed by conventional ceramic processing techniques, and sintered at 1450°C. The dusted γ-Ca2SiO4 powder was uniaxially pressed into 0.4 cm x 0.4 cm x 4 cm bars under 34 MPa and cold isostatically pressed under 172 MPa. The γ-Ca2SiO4 bars were melted by a 10 KW-CO2 laser.

Use of fractals to describe microstructures of porous thick-film platinum electrodes

1992 ◽  
Vol 50 (1) ◽  
pp. 314-315
Author(s):  
Steven D. Toteda
Keyword(s):  
Fractal Dimension ◽  
Power Plants ◽  
Electrical Response ◽  
Cubic Phase ◽  
Platinum Electrodes ◽  
Fine Grained ◽  
Impedance Response ◽  
Platinum Particles ◽  
Energy Surfaces ◽  
Highly Porous

Zirconia oxygen sensors, in such applications as power plants and automobiles, generally utilize platinum electrodes for the catalytic reaction of dissociating O2 at the surface. The microstructure of the platinum electrode defines the resulting electrical response. The electrode must be porous enough to allow the oxygen to reach the zirconia surface while still remaining electrically continuous. At low sintering temperatures, the platinum is highly porous and fine grained. The platinum particles sinter together as the firing temperatures are increased. As the sintering temperatures are raised even further, the surface of the platinum begins to facet with lower energy surfaces. These microstructural changes can be seen in Figures 1 and 2, but the goal of the work is to characterize the microstructure by its fractal dimension and then relate the fractal dimension to the electrical response. The sensors were fabricated from zirconia powder stabilized in the cubic phase with 8 mol% percent yttria. Each substrate was sintered for 14 hours at 1200°C. The resulting zirconia pellets, 13mm in diameter and 2mm in thickness, were roughly 97 to 98 percent of theoretical density. The Engelhard #6082 platinum paste was applied to the zirconia disks after they were mechanically polished ( diamond). The electrodes were then sintered at temperatures ranging from 600°C to 1000°C. Each sensor was tested to determine the impedance response from 1Hz to 5,000Hz. These frequencies correspond to the electrode at the test temperature of 600°C.

MANUFACTURING NOVEL HEAT TRANSFER DEVICES BY SELECTIVE LASER MELTING

Equipment ◽  
2006 ◽  
Author(s):  
S. Tsopanos ◽  
M. Wong ◽  
I. Owen ◽  
C. J. Sutcliffe
Keyword(s):  
Heat Transfer ◽  
Selective Laser Melting ◽  
Laser Melting

Properties of Ti-6Al-4V titanium alloys obtained by selective laser melting

2019 ◽  
pp. 46-57
Author(s):  
M.A. Kaplan ◽  
◽  
М.A. Smirnov ◽  
A.A. Kirsankin ◽  
M.A. Sevostyanov ◽  
...  
Keyword(s):  
Titanium Alloys ◽  
Selective Laser Melting ◽  
Laser Melting
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