scholarly journals Characterization of Raw Material Powder Extracted at High Temperature from Fluoride Groundwater

2020 ◽  
Vol 9 (9) ◽  
pp. 2989-2994
Author(s):  
Valipenta Narasimhulu ◽  
Sudhakar Bansod ◽  
Lakshmi Srinivasa Rao Kundeti ◽  
Ravindra M. Kumbhare
Keyword(s):  
High Temperature ◽  
Raw Material ◽  
Material Powder

PREPARATION AND CHARACTERIZATION OF CaZrO3COATING ON GRAPHITE FOR TiNi ALLOY MELTING

2019 ◽  
Vol 27 (05) ◽  
pp. 1950152
Author(s):  
BIN ZHAN ◽  
YUE ZHANG ◽  
YUNFENG XIAO ◽  
CAIFEN WANG ◽  
XIANGDONG ZHANG
Keyword(s):  
High Temperature ◽  
Color Change ◽  
Raw Material ◽  
Flame Spraying ◽  
Tini Alloy ◽  
High Temperature Process ◽  
Calcium Metal ◽  
Melting Material

Graphite is a favorable melting material of TiNi alloy. In order to reduce the carbon increment during high temperature process, the protective CaZrO3 coating has been prepared using different methods. First, CaZrO3 powder was synthesized via solid-state reaction using calcium metal as raw material. The coating on graphite was prepared by flame spraying, plasma spraying and dipping sintering, then it was observed and characterized. The results show that the apparent quality of the obtained coating is intactness. Here, the spraying coating is composition uniform and structure compact; the dipping coating exhibits an obvious color change and presents the typical porous structure.

Surface methods for monitoring the densification of parts in the selective laser sintering process

2014 ◽  
Vol 20 (2) ◽  
pp. 157-163 ◽  
Author(s):  
Grazielle de Oliveira Setti ◽  
Jorge Vicente Lopes da Silva ◽  
Marcelo Fernandes de Oliveira ◽  
Izaque Alves Maia ◽  
Dosil Pereira de Jesus ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Selective Laser Sintering ◽  
Raw Material ◽  
Content Type ◽  
Density Measurements ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Nylon 12 ◽  
Material Powder

Purpose – The purpose of this paper is to characterize polyamide parts prepared by the SLS process using techniques that are dependent on surface properties and compare the results to density measurements in order to assess which technique better reflects the degree of densification achieved using different laser power levels. Design/methodology/approach – Fabrication of Nylon 12 (Duraform PA) samples and their characterization by apparent density measurements, perfilometry, Raman spectroscopy, scanning electron microscopy, specific surface area and contact angle measurements. Findings – Methods dependent on surface analysis are not suitable indicators of the degree of sample densification. Among the surface methods, the results from Raman spectroscopy are the ones with the best performance. Incipient sintering of the superficial layers and raw material powder on the surface, inherent to the parts made by the SLS process, strongly interfere with the characterization. Originality/value – Quantitative comparison of a number of surface probing methods for monitoring densification of SLS parts. Characterization of sample surfaces with and without raw material powder.

scholarly journals Fabrication and Characterization of Quinary High Entropy-Ultra-High Temperature Diborides

Ceramics ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 108-120
Author(s):  
Simone Barbarossa ◽  
Roberto Orrù ◽  
Valeria Cannillo ◽  
Antonio Iacomini ◽  
Sebastiano Garroni ◽  
...  
Keyword(s):  
High Temperature ◽  
Single Phase ◽  
Nominal Composition ◽  
High Entropy ◽  
Chemical Complexity ◽  
Alternative Processing ◽  
Plasma Sintering ◽  
High Temperature Synthesis ◽  
Spark Plasma

Due to their inherent chemical complexity and their refractory nature, the obtainment of highly dense and single-phase high entropy (HE) diborides represents a very hard target to achieve. In this framework, homogeneous (Hf0.2Nb0.2Ta0.2Mo0.2Ti0.2)B2, (Hf0.2Zr0.2Ta0.2Mo0.2Ti0.2)B2, and (Hf0.2Zr0.2Nb0.2Mo0.2Ti0.2)B2 ceramics with high relative densities (97.4, 96.5, and 98.2%, respectively) were successfully produced by spark plasma sintering (SPS) using powders prepared by self-propagating high-temperature synthesis (SHS). Although the latter technique did not lead to the complete conversion of initial precursors into the prescribed HE phases, such a goal was fully reached after SPS (1950 °C/20 min/20 MPa). The three HE products showed similar and, in some cases, even better mechanical properties compared to ceramics with the same nominal composition attained using alternative processing methods. Superior Vickers hardness and elastic modulus values were found for the (Hf0.2Nb0.2Ta0.2Mo0.2Ti0.2)B2 and the (Hf0.2Zr0.2Ta0.2Mo0.2Ti0.2)B2 systems, i.e., 28.1 GPa/538.5 GPa and 28.08 GPa/498.1 GPa, respectively, in spite of the correspondingly higher residual porosities (1.2 and 2.2 vol.%, respectively). In contrast, the third ceramic, not containing tantalum, displayed lower values of these two properties (25.1 GPa/404.5 GPa). However, the corresponding fracture toughness (8.84 MPa m1/2) was relatively higher. This fact can be likely ascribed to the smaller residual porosity (0.3 vol.%) of the sintered material.

scholarly journals Rheological Characterization of a Concentrated Phosphate Slurry

Fluids ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 178
Author(s):  
Souhail Maazioui ◽  
Abderrahim Maazouz ◽  
Fayssal Benkhaldoun ◽  
Driss Ouazar ◽  
Khalid Lamnawar
Keyword(s):  
Flow Behavior ◽  
Continuous Phase ◽  
Raw Material ◽  
Rheological Characterization ◽  
Phosphate Ore ◽  
Insoluble Particles ◽  
Experimental Protocols ◽  
Solid Liquid

Phosphate ore slurry is a suspension of insoluble particles of phosphate rock, the primary raw material for fertilizer and phosphoric acid, in a continuous phase of water. This suspension has a non-Newtonian flow behavior and exhibits yield stress as the shear rate tends toward zero. The suspended particles in the present study were assumed to be noncolloidal. Various grades and phosphate ore concentrations were chosen for this rheological investigation. We created some experimental protocols to determine the main characteristics of these complex fluids and established relevant rheological models with a view to simulate the numerical flow in a cylindrical pipeline. Rheograms of these slurries were obtained using a rotational rheometer and were accurately modeled with commonly used yield-pseudoplastic models. The results show that the concentration of solids in a solid–liquid mixture could be increased while maintaining a desired apparent viscosity. Finally, the design equations for the laminar pipe flow of yield pseudoplastics were investigated to highlight the role of rheological studies in this context.

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...

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