Bonding CVD Diamond to WC-Co by High Pressure - High Temperature Processing

2006 ◽  
Vol 987 ◽  
Author(s):  
Naira Maria Balzaretti ◽  
Altair Soria Pereira ◽  
Rafael Vieira Camerini ◽  
Sérgio Ivan dos Santos ◽  
João Alziro Herz da Jornada
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
High Performance ◽  
Microwave Plasma ◽  
Cutting Tools ◽  
Surface Region ◽  
Diamond Powder ◽  
Cvd Diamond ◽  
Sem Images ◽  
High Pressure High Temperature

AbstractIn this work we investigate the effect of processing at high pressure-high temperature (HPHT) on the adhesion of CVD diamond coatings on WC-Co substrates. The samples consisted of WC-Co substrates coated with thin diamond films (10 – 40 μm thick) grown by microwave plasma (MWCVD) CVD. The substrates were previously etched in order to remove the Co from the surface region. The adhesion of the film and its wear resistance improved after the HPHT treatment. SEM images of the cross section of the coated substrate revealed that Co infiltrated back to the region where it was previously removed. The results indicate that it is possible to take advantage of the HPHT plants already available around the world to produce, besides PCD's and diamond powder, high-performance CVD diamond cutting tools with the advantage of requiring less demanding processing conditions.

Study of the Diamond 5%wt- Cobalt Sintering under the HPHT Lowest Limit

2005 ◽  
Vol 498-499 ◽  
pp. 225-230
Author(s):  
F.T.C. Lima ◽  
Guerold Sergueevitch Bobrovinitchii ◽  
Marcello Filgueira
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Oil Industry ◽  
Diamond Powder ◽  
Structure Evolution ◽  
Binder Phase ◽  
Micro Structure ◽  
High Pressure High Temperature

Diamond composites consist in the diamond powder mixed with a binder phase, which sintering is carried out by means of the High Pressure-High Temperature (HPHT) techniques. These composites are widely used in the cutters of drillers for the oil industry, and as inserts for machining. In this work was used a mix of diamond + 5% weight cobalt. Sintering was accomplished under the HPHT Lowest Limit conditions: P=7GPa and T=15000C for times of t=10-30-60 seconds, aiming at the densification study under these conditions. Results are shown as a function of the sintered micro-structure evolution, cobalt influence on densification, graphitization, and hardness of the sintered parts.

scholarly journals High-pressure synthesis and crystal structure of the mixed-cation borate Ga4In4B15O33(OH)3

2019 ◽  
Vol 74 (4) ◽  
pp. 357-363
Author(s):  
Daniela Vitzthum ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Mixed Cation ◽  
High Pressure High Temperature ◽  
Pressure Synthesis

AbstractThe mixed cation triel borate Ga4In4B15O33(OH)3 was synthesized in a Walker-type multianvil apparatus at high-pressure/high-temperature conditions of 12.5 GPa and 1300°C. Although the product could not be reproduced in further experiments, its crystal structure could be reliably determined via single-crystal X-ray diffraction data. Ga4In4B15O33(OH)3 crystallizes in the tetragonal space group I41/a (origin choice 2) with the lattice parameters a = 11.382(2), c = 15.244(2) Å, and V = 1974.9(4) Å3. The structure of the quaternary triel borate consists of a complex network of BO4 tetrahedra, edge-sharing InO6 octahedra in dinuclear units, and very dense edge-sharing GaO6 octahedra in tetranuclear units.

Iodine-mediated high-pressure high-temperature carbonization of hydrocarbons and synthesis of nanodiamonds

2021 ◽  
Vol 137 ◽  
pp. 111189
Author(s):  
E.A. Ekimov ◽  
K.M. Kondrina ◽  
I.P. Zibrov ◽  
S.G. Lyapin ◽  
M.V. Lovygin ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
High Pressure High Temperature

scholarly journals Multianvil High-Pressure/High-Temperature Synthesis and Characterization of multiferroic HP-Co3TeO6

2021 ◽  
Author(s):  
Gunter Heymann ◽  
Elisabeth Selb ◽  
Toni Buttlar ◽  
Oliver Janka ◽  
Martina Tribus ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Type Structure ◽  
Synthesis And Characterization ◽  
Temperature Synthesis ◽  
Space Group ◽  
Crystal System ◽  
High Temperature Synthesis ◽  
High Pressure High Temperature

By high-pressure/high-temperature multianvil synthesis a new high-pressure (HP) phase of Co3TeO6 was obtained. The compound crystallizes in the acentric trigonal crystal system of the Ni3TeO6-type structure with space group R3...

Experimental investigation of wall heat transfer due to spray combustion in a high-pressure/high-temperature vessel

2021 ◽  
pp. 146808742110072
Author(s):  
Karri Keskinen ◽  
Walter Vera-Tudela ◽  
Yuri M Wright ◽  
Konstantinos Boulouchos
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
High Pressure ◽  
High Temperature ◽  
High Speed ◽  
Transfer Problem ◽  
Wall Heat Transfer ◽  
Gas Temperature ◽  
Reference Case ◽  
High Pressure High Temperature

Combustion chamber wall heat transfer is a major contributor to efficiency losses in diesel engines. In this context, thermal swing materials (adapting to the surrounding gas temperature) have been pinpointed as a promising mitigative solution. In this study, experiments are carried out in a high-pressure/high-temperature vessel to (a) characterise the wall heat transfer process ensuing from wall impingement of a combusting fuel spray, and (b) evaluate insulative improvements provided by a coating that promotes thermal swing. The baseline experimental condition resembles that of Spray A from the Engine Combustion Network, while additional variations are generated by modifying the ambient temperature as well as the injection pressure and duration. Wall heat transfer and wall temperature measurements are time-resolved and accompanied by concurrent high-speed imaging of natural luminosity. An investigation with an uncoated wall is carried out with several sensor locations around the stagnation point, elucidating sensor-to-sensor variability and setup symmetry. Surface heat flux follows three phases: (i) an initial peak, (ii) a slightly lower plateau dependent on the injection duration, and (iii) a slow decline. In addition to the uncoated reference case, the investigation involves a coating made of porous zirconia, an established thermal swing material. With a coated setup, the projection of surface quantities (heat flux and temperature) from the immersed measurement location requires additional numerical analysis of conjugate heat transfer. Starting from the traces measured beneath the coating, the surface quantities are obtained by solving a one-dimensional inverse heat transfer problem. The present measurements are complemented by CFD simulations supplemented with recent rough-wall models. The surface roughness of the coated specimen is indicated to have a significant impact on the wall heat flux, offsetting the expected benefit from the thermal swing material.

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