Alumina-Based Functional Materials Hardened with Al or Ti and Al-nitride or Ti-nitride Dispersions

2010 ◽  
Vol 1276 ◽  
Author(s):  
José G. Miranda-Hernández ◽  
Elizabeth Refugio-Garcia ◽  
Elizabeth Garfias-García ◽  
Enrique Rocha-Rangel
Keyword(s):  
Aluminum Nitride ◽  
Titanium Nitride ◽  
Functional Materials ◽  
High Energy ◽  
Nitride Layer ◽  
Layer Growth ◽  
Density Level ◽  
Functional Material ◽  
Energy Ball ◽  
Titanium Powders

AbstractThe synthesis of Al2O3-based functional materials having 10 vol. % of fine aluminum or titanium and aluminum-disperse or titanium-dispersed nitride hardened-particles has been explored. Two experimental steps have been set for the synthesis; specifically, sintering of Al2O3-aluminum or Al2O3-titanium powders which were thoroughly mixed under high energy ball-milling, pressureless-sintered at 1400°C during 1 h in argon atmosphere and then for the second step it was induced formation of aluminum nitride or titanium nitride at 500°C during different times (24, 72 and 120 h) by a nitriding process via immersion in ammoniac salts. SEM analyses of the microstructures obtained in nitride bodies were performed in order to know the effect of the ammoniac salts used as nitrating on the microstructure of aluminum or titanium for each studied functional material. It was observed that an aluminum nitride or titanium nitride layer growth from the surface into the bulk and reaches different depth as the nitriding time of the functional material was increased. The use of aluminum or titanium significantly enhanced density level and hardness of the functional materials.

Combustion Synthesis of TiN Induced by High-energy Ball Milling of Ti Under Nitrogen Atmosphere

2002 ◽  
Vol 17 (7) ◽  
pp. 1655-1663 ◽  
Author(s):  
F. J. Gotor ◽  
M. D. Alcalá ◽  
C. Real ◽  
J. M. Criado
Keyword(s):  
Titanium Nitride ◽  
Constant Pressure ◽  
Nitrogen Pressure ◽  
High Energy ◽  
Nitrogen Atmosphere ◽  
High Yield ◽  
Energy Ball ◽  
Titanium Powders ◽  
Gas Reactions ◽  
Full Conversion

A planetary ball-mill device that enables one to perform solid-gas reactions at constant pressure was developed. Titanium powders were ball milled under nitrogen at a spinning rate of 960 rpm. The influence of the nitrogen pressure on the mechanochemical reactivity of titanium was analyzed at 1.5 and 11 bars. A spontaneous combustion took place during the grinding process, leading to a high yield of TiN for short milling times. The conversion of titanium into titanium nitride was facilitated by increasing the nitrogen pressure. At 11 bars, full conversion was reached for grinding times shorter than 5 h. Titanium nitride obtained in this way exhibited a high sintering activity.

Characterization of titanium powders processed in n-hexane by high-energy ball milling

2020 ◽  
Vol 110 (7-8) ◽  
pp. 1681-1690
Author(s):  
A. H. Restrepo ◽  
J. M. Ríos ◽  
F. Arango ◽  
E. Correa ◽  
A. A. Zuleta ◽  
...  
Keyword(s):  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Energy Ball ◽  
Titanium Powders

scholarly journals Functional-Material-Based Touch Interfaces for Multidimensional Sensing for Interactive Displays: A Review

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Shuo Gao
Keyword(s):  
Smart Cities ◽  
Low Cost ◽  
Circuit Complexity ◽  
Functional Materials ◽  
High Energy ◽  
Functional Material ◽  
Types Of Information ◽  
High Energy Consumption ◽  
Interactive Displays ◽  
Touch Interfaces

Multidimensional sensing is a highly desired attribute for allowing human-machine interfaces (HMIs) to perceive various types of information from both users and the environment, thus enabling the advancement of various smart electronics/applications, e.g., smartphones and smart cities. Conventional multidimensional sensing is achieved through the integration of multiple discrete sensors, which introduces issues such as high energy consumption and high circuit complexity. These disadvantages have motivated the widespread use of functional materials for detecting various stimuli at low cost with low power requirements. This work presents an overview of simply structured touch interfaces for multidimensional (x-y location, force and temperature) sensing enabled by piezoelectric, piezoresistive, triboelectric, pyroelectric and thermoelectric materials. For each technology, the mechanism of operation, state-of-the-art designs, merits, and drawbacks are investigated. At the end of the article, the author discusses the challenges limiting the successful applications of functional materials in commercial touch interfaces and corresponding development trends.

Deposition of Copper Thin Films on Titanium Nitride Layer Prepared by Flow Modulation CVD Technology

2004 ◽  
Vol 449-452 ◽  
pp. 457-460
Author(s):  
Nam Ihn Cho ◽  
Min Chul Kim ◽  
Kyung Hwa Rim ◽  
Ho Jung Chang ◽  
Keeyoung Jun ◽  
...  
Keyword(s):  
Thin Films ◽  
Titanium Nitride ◽  
Diffusion Barrier ◽  
High Vacuum ◽  
Reduction Process ◽  
Chemical Vapor ◽  
Barrier Properties ◽  
Nitride Layer ◽  
Layer Growth ◽  
Flow Modulation

Copper (Cu) thin films have been deposited onto titanium nitride (TiN) layer which was previously prepared by flow modulation chemical vapor deposition (FMCVD technology. The diffusion barrier properties of the TiN layer to Cu have been studied depending upon the post-annealing and the sample preparation conditions of the TiN layer. The Cu deposition has performed by RF magnetron sputtering with 5N target in the high vacuum ambient. The FMCVD process has carried out in a single CVD chamber by switching TiCl4flow to the argon flow cyclically, which creates sequential deposition of TiN layer and chlorine reduction process. The higher flow modulation cycle and Ar purge time during the TiN layer growth have been observed to provide the better diffusion barrier property in Auger depth profile and X-ray diffraction analysis.

Ion beam synthesis of nitride layers in iron

1992 ◽  
Vol 7 (10) ◽  
pp. 2689-2712 ◽  
Author(s):  
A.M. Vredenberg ◽  
C.M. Pérez-Martin ◽  
J.S. Custer ◽  
D.O. Boerma ◽  
L. de Wit ◽  
...  
Keyword(s):  
Ion Beam ◽  
High Energy ◽  
Nitride Layer ◽  
Layer Growth ◽  
Stable Phase ◽  
Iron Nitride ◽  
High Dose ◽  
Nitride Layers ◽  
Induced Defects ◽  
Kinetics Of

Stoichiometric iron nitride layers have been synthesized by high dose, high energy nitrogen implantation into Fe using a two-step implantation process. First, a nitrogen preimplantation at ~100 °C is used to form nitride precipitates. A low temperature is necessary to restrict the nitrogen mobility. Second, 1 MeV implantation at ~300 °C leads to the formation of a stoichiometric γ′–Fe4N layer at the position of the preimplanted N atoms. Growth of this nitride layer proceeds by diffusion of the implanted N through either the α–Fe matrix (for 200 or 500 keV preimplantations) or the nitride layer itself (for 1 MeV preimplantation). During annealing above 350 °C the γ′ layers dissolve in a planar fashion, characterized by an activation energy of 2.3 eV. Phase formation during preimplantation and phase transformations during subsequent annealing or hot implantation can be understood from the thermodynamics for the Fe–N system, while the kinetics of layer growth is influenced by the beam-induced defects. The experiment and model suggest that γ′ is not a thermodynamically stable phase below 310 ± 10 °C and should decompose into α (ferrite) and ∊ nitride.

Production of BaTiO2 Nanocrystalline Powders by High Energy Milling and Piezoelectric Properties of Corresponding Ceramics

2013 ◽  
Vol 547 ◽  
pp. 133-138
Author(s):  
K. Chandramani Singh ◽  
Chongtham Jiten
Keyword(s):  
Particle Size ◽  
Piezoelectric Properties ◽  
Average Particle Size ◽  
Hysteresis Loops ◽  
Functional Materials ◽  
High Energy ◽  
Nanocrystalline Powders ◽  
Average Particle ◽  
Ceramic Samples ◽  
Energy Ball

Barium titanate (BaTiO3 or BT) has become one of the most studied functional materials due to its potential application as multilayer ceramic capacitors, PTC thermistors, electromechanical devices, piezoelectric transducers, actuators, dynamic RAM or logic circuitry as well as a great variety of electro-optical devices. In the present study, high energy ball milling has been used to produce nanocrystalline powders of BT. Two categories of powders having average particle size of 35 nm and 25 nm were prepared by setting the milling speed at 250 rpm and 300 rpm respectively, fixing the milling time at 30 hours. Four ceramic samples, BT35-1350, BT25-1350, BT35-1400 and BT25-1400, were formed by sintering the two types of powders at 1350oC and 1400oC for 3 hours. The ferroelectric and piezoelectric properties of the ceramic samples were studied and found to be dependent on the size of the starting nanopowders. The bulk density and piezoelectric constant (d33) of B25-1350 were found to be less than those of BT35-1350, while the reverse was true in case of BT25-1400 and BT35-1400. Well saturated P-E hysteresis loops were observed for all the ceramics with the size and shape of the loops appearing different for the four samples. For both the pairs of ceramics sintered at 1350oC and 1400oC, the remnant polarization (Pr) decreases with starting particle size, that is, as we go from BT35-1350 to BT25-1350 as well as from BT35-1400 to BT25-1400. However, with decreasing particle size of the starting powders, the coercive field (Ec) increases for the ceramics sintered at 1350oC and decreases for the ceramics sintered at 1400oC. The study reveals the importance of an optimized combination of the size of the starting nanopowders and sintering temperature for obtaining BT ceramics with the desired properties.

scholarly journals Effects of Recycled Fe2O3 Nanofiller on the Structural, Thermal, Mechanical, Dielectric, and Magnetic Properties of PTFE Matrix

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2332
Author(s):  
Ahmad Mamoun Khamis ◽  
Zulkifly Abbas ◽  
Raba’ah Syahidah Azis ◽  
Ebenezer Ekow Mensah ◽  
Ibrahim Abubakar Alhaji
Keyword(s):  
Electron Microscopy ◽  
High Energy ◽  
Filler Loading ◽  
Complex Permeability ◽  
X Ray Diffraction ◽  
Thermal Expansion Coefficients ◽  
Transmission Electron ◽  
Energy Ball ◽  
Hematite Fe2o3 ◽  
Ptfe Composites

The purpose of this study was to improve the dielectric, magnetic, and thermal properties of polytetrafluoroethylene (PTFE) composites using recycled Fe2O3 (rFe2O3) nanofiller. Hematite (Fe2O3) was recycled from mill scale waste and the particle size was reduced to 11.3 nm after 6 h of high-energy ball milling. Different compositions (5–25 wt %) of rFe2O3 nanoparticles were incorporated as a filler in the PTFE matrix through a hydraulic pressing and sintering method in order to fabricate rFe2O3–PTFE nanocomposites. The microstructure properties of rFe2O3 nanoparticles and the nanocomposites were characterized through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HRTEM). The thermal expansion coefficients (CTEs) of the PTFE matrix and nanocomposites were determined using a dilatometer apparatus. The complex permittivity and permeability were measured using rectangular waveguide connected to vector network analyzer (VNA) in the frequency range 8.2–12.4 GHz. The CTE of PTFE matrix decreased from 65.28×10−6/°C to 39.84×10−6/°C when the filler loading increased to 25 wt %. The real (ε′) and imaginary (ε″) parts of permittivity increased with the rFe2O3 loading and reached maximum values of 3.1 and 0.23 at 8 GHz when the filler loading was increased from 5 to 25 wt %. A maximum complex permeability of 1.1−j0.07 was also achieved by 25 wt % nanocomposite at 10 GHz.

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