Room-temperature Repeatedly Processable Baroplastic/Boron Nitride Thermal Management Composite

2021 ◽  
Author(s):  
Jia-Ning Qiao ◽  
Yu Fan Hu ◽  
Xu Ji ◽  
Jian-Hua Tang ◽  
Jun Lei ◽  
...  
Keyword(s):  
High Temperature ◽  
Boron Nitride ◽  
Thermal Degradation ◽  
Energy Saving ◽  
Thermal Management ◽  
Room Temperature ◽  
High Repeatability

Baroplastics show great superiorities over common polymers that are processed at high temperature, such as energy-saving, less thermal degradation, high repeatability and durability, etc. In this work, we synthesized a...

Cubic Boron Nitride as a New Semiconductor for Optoelectronics: Luminescence Properties and Potentialities

1989 ◽  
Vol 162 ◽  
Author(s):  
Koh Era ◽  
Osamu Mishima
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Boron Nitride ◽  
Room Temperature ◽  
Cubic Boron Nitride ◽  
Visible Region ◽  
Vibrational Structure ◽  
Luminescence Properties ◽  
Optoelectronic Applications ◽  
P Type

ABSTRACTIn cubic boron nitride made by high pressure and high temperature technique in our institute, we have found three luminescence bands in the ultraviolet and the short visible region at room temperature by cathode-ray excitation. They are: a band having vibrational structure and ascribable to undoped state of the crystal, a band ascribable to p-type doping and a band ascribable to n-type doping. Discussion is made on differences between the injection luminescence and the cathodoluminescence. Potentialities and difficulties in realizing the potentialities of cBN for optoelectronic applications are discussed.

Influence of Graphite on Tribological Properties of Hexagonal Boron Nitride Hybrid/Polyimide Composites in Wide Temperature Range

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Yanming Wang ◽  
Peng Cai ◽  
Tingmei Wang ◽  
Qihua Wang
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Boron Nitride ◽  
Room Temperature ◽  
Hexagonal Boron Nitride ◽  
Transfer Film ◽  
Antiwear Property ◽  
Wear Rates ◽  
Higher Temperature ◽  
Polyimide Composites

Tribological and mechanical properties of aramid fiber (AF), graphite (Gr), and hexagonal boron nitride (h-BN) hybrid polyimide composites were investigated under room and high temperature. Results show that, Gr in composite reinforced with AF and h-BN can reduce coefficient of friction (COF) and improve antiwear property of composites under room temperature. Gr can accelerate the formation of transfer film under high temperature without sacrificing the wear resistant of composites. Transfer film of composites reinforced with Gr and h-BN simultaneously present more smooth and uniform compared with that of composites reinforced with only AF and h-BN. However, under higher temperature, composite reinforced with pure Gr present higher COFs and wear rates (WRs) compared with composites filled with h-BN and Gr simultaneously. Comprehensively, composite filled with 10% AF, 3% h-BN, and 4% Gr is the optimum composition.

scholarly journals Ultrahigh thermal conductivity in isotope-enriched cubic boron nitride

Science ◽  
2020 ◽  
Vol 367 (6477) ◽  
pp. 555-559 ◽  
Author(s):  
Ke Chen ◽  
Bai Song ◽  
Navaneetha K. Ravichandran ◽  
Qiye Zheng ◽  
Xi Chen ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Thermal Management ◽  
High Power ◽  
Room Temperature ◽  
Cubic Boron Nitride ◽  
Wide Bandgap ◽  
Boron Isotopes ◽  
Fundamental Interest ◽  
Boron Phosphide

Materials with high thermal conductivity (κ) are of technological importance and fundamental interest. We grew cubic boron nitride (cBN) crystals with controlled abundance of boron isotopes and measured κ greater than 1600 watts per meter-kelvin at room temperature in samples with enriched 10B or 11B. In comparison, we found that the isotope enhancement of κ is considerably lower for boron phosphide and boron arsenide as the identical isotopic mass disorder becomes increasingly invisible to phonons. The ultrahigh κ in conjunction with its wide bandgap (6.2 electron volts) makes cBN a promising material for microelectronics thermal management, high-power electronics, and optoelectronics applications.

High temperature thermal management with boron nitride nanosheets

Nanoscale ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 167-173 ◽  
Author(s):  
Yilin Wang ◽  
Lisha Xu ◽  
Zhi Yang ◽  
Hua Xie ◽  
Puqing Jiang ◽  
...  
Keyword(s):  
High Temperature ◽  
Boron Nitride ◽  
Thermal Management ◽  
Power Density ◽  
High Power ◽  
Heat Dissipation ◽  
Rapid Development ◽  
High Power Density ◽  
Boron Nitride Nanosheets

The rapid development of high power density devices requires more efficient heat dissipation.

ABOUT HEAT CAPACITY OF TITANIUM CARBIDE TiCx

2019 ◽  
pp. 56-66
Author(s):  
I. Khidirov ◽  
V. V. Getmanskiy ◽  
A. S. Parpiev ◽  
Sh. A. Makhmudov
Keyword(s):  
Heat Capacity ◽  
High Temperature ◽  
Titanium Carbide ◽  
Temperature Dependence ◽  
Carbon Concentration ◽  
Room Temperature ◽  
Thermodynamic Characteristics ◽  
Liquid Nitrogen Temperature ◽  
Analysis Data ◽  
Thermal Excitation

This work relates to the field of thermophysical parameters of refractory interstitial alloys. The isochoric heat capacity of cubic titanium carbide TiCx has been calculated within the Debye approximation in the carbon concentration  range x = 0.70–0.97 at room temperature (300 K) and at liquid nitrogen temperature (80 K) through the Debye temperature established on the basis of neutron diffraction analysis data. It has been found out that at room temperature with decrease of carbon concentration the heat capacity significantly increases from 29.40 J/mol·K to 34.20 J/mol·K, and at T = 80 K – from 3.08 J/mol·K to 8.20 J/mol·K. The work analyzes the literature data and gives the results of the evaluation of the high-temperature dependence of the heat capacity СV of the cubic titanium carbide TiC0.97 based on the data of neutron structural analysis. It has been proposed to amend in the Neumann–Kopp formula to describe the high-temperature dependence of the titanium carbide heat capacity. After the amendment, the Neumann–Kopp formula describes the results of well-known experiments on the high-temperature dependence of the heat capacity of the titanium carbide TiCx. The proposed formula takes into account the degree of thermal excitation (a quantized number) that increases in steps with increasing temperature.The results allow us to predict the thermodynamic characteristics of titanium carbide in the temperature range of 300–3000 K and can be useful for materials scientists.

Nanocomposite Polyurethane Foams Via POSS Blends

2002 ◽  
Vol 733 ◽  
Author(s):  
Brock McCabe ◽  
Steven Nutt ◽  
Brent Viers ◽  
Tim Haddad
Keyword(s):  
High Temperature ◽  
Sample Preparation ◽  
Room Temperature ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Polyurethane Foams ◽  
Development Projects ◽  
Polymer Systems ◽  
Polyurethane Resin ◽  
Military Development

AbstractPolyhedral Oligomeric Silsequioxane molecules have been incorporated into a commercial polyurethane formulation to produce nanocomposite polyurethane foam. This tiny POSS silica molecule has been used successfully to enhance the performance of polymer systems using co-polymerization and blend strategies. In our investigation, we chose a high-temperature MDI Polyurethane resin foam currently used in military development projects. For the nanofiller, or “blend”, Cp7T7(OH)3 POSS was chosen. Structural characterization was accomplished by TEM and SEM to determine POSS dispersion and cell morphology, respectively. Thermal behavior was investigated by TGA. Two methods of TEM sample preparation were employed, Focused Ion Beam and Ultramicrotomy (room temperature).

Sign in / Sign up

Export Citation Format

Share Document