SINASILICA
Spherical aluminum oxide
spherical aluminum oxide
The spherical alumina produced by high temperature melting and spraying method has the characteristics of high spherical rate and high content of α phase alumina. It shows superior properties when used as filler for rubber and plastic and as raw material for ceramics.
Al2O3 with ordinary irregular shape is uniformly dispersed and melted into liquid droplets in high temperature flame, suspended in high temperature gas formed by flame, becomes spherical under the action of surface tension, and then undergoes rapid cooling and "solidification", and then undergoes screening, purification and other processes to obtain the final product. The obtained alumina has high spheroidization rate, controllable particle size distribution and high purity.
The product is widely used as thermal interface material, thermal engineering plastic and thermal filler of aluminum clad copper plate because of its unique properties such as high thermal conductivity and good fluidity.
2、Our product specifications:
specification of spherical alumina | ||||||||||
mesh number | 100 mesh | 200 mesh | 325 mesh | 600 mesh | 1250 mesh | 3000 mesh | 5000 mesh | 8000 mesh | 9000 mesh | 15,000 mesh |
fineness | 100μm | 80μm | 50μm | 20μm | 10μm | 5μm | 3μm | 2μm | 1.5μm | 0.5μm |
3、Main characteristics of spherical alumina:
l High purity
The product is made by chemical treatment of raw material to remove the oxide of silicon, iron, titanium and so on, and the purity of powder is up to 99.7%.
l excellent thermal conductivity
The spherical shape of the product can realize the multidirectional heat transfer, and the dispersion of the product in the system is good, and the thermal conductivity of the product is high.
It can be filled with high density, and the mixture with high thermal conductivity and good heat dissipation can be obtained compared with crystalline silicon powder.
l High fill rate
The particle has high spherical ratio and wide particle size distribution, which can be used to fill silica gel, epoxy, rubber and plastic with high density, and obtain mixture with low viscosity and good fluidity.
l low wear resistance
Because of its spherical appearance, the wear of mixing machine, molding machine and mould is greatly reduced, and the service life of equipment is prolonged.
l narrow particle size distribution
The particle size distribution of a single particle is relatively concentrated, and the interval frequency distribution curve in the particle size analysis report is a narrow single peak.
IV. Conventional Physical Properties and Main Components of Spherical Alumina
project | unit | Typical value |
nodularity | % | 95 |
Moh's hardness | - | 8 |
density | g/cm³ | 3.85×10³ |
whiteness | - | 95 |
melting point | ℃ | 2054 |
boiling point | ℃ | 2980 |
thermal conductivity | W/K.m | ≥1000℃ 3.1 |
Main chemical components of spherical alumina | ||
project | unit | Typical value |
Al2O3 | % | ≥99.8 |
Fe2O3 | Ppm | ≤160 |
SiO2 | ppm | ≤150 |
Na2O | ppm | ≤50 |
K2O | ppm | ≤40 |
solid body | angular | Approximately 1900°C |
initiation of melting | angular | Approximately 2100°C |
liquid state | Spheroid | Approximately 2300°C |
liquid state | sphere | ＞2300℃ |
5. Main application areas of spherical alumina:
l thermal interface material
Thermal conductive silicone gaskets, thermal conductive grease, thermal conductive potting compounds, thermal conductive double-sided tapes, phase change materials, heat sinks, fillers for heat dissipation substrates (MC substrates), fillers for silicone thermal conductive adhesives and mixtures, etc. Thermal conductive silicone gaskets, thermal conductive grease, thermal conductive potting compounds, thermal conductive double-sided tapes, phase change materials, heat sinks, fillers for heat dissipation substrates (MC substrates), fillers for silicone thermal conductive adhesives and mixtures, etc.
l thermal conductive engineering plastics
LED lampshades, switch casings, electronic product enclosures, and heat dissipation components for electrical appliances (including heat sinks, thermal paste for heat dissipation substrates, and MC substrates). LED lampshades, switch casings, electronic product enclosures, and heat dissipation components for electrical appliances (including heat sinks, thermal paste for heat dissipation substrates, and MC substrates).
l Al Based Copper Clad Laminate and Semiconductor Packaging
High-power LED circuit substrates, power circuit boards, and fillers for semiconductor encapsulation resins
l Other fields
Alumina ceramic filter, raw materials for artificial corundum and artificial sapphire, etc.
thermal spray coatings, etc.
6. Why Choose Spherical Aluminum Oxide:
Alumina, with the chemical formula Al₂O₃, is a white powder of high hardness. It has a melting point of 2054°C and a boiling point of 2980°C. This ionized crystalline compound is commonly used in refractory materials due to its porous structure, high dispersion, insulating properties, stable crystal phase, high hardness, and excellent dimensional stability.
Spherical alumina is a powdered alumina material produced through high-temperature melting and jet calcination of irregularly shaped high-purity alumina, followed by sieving and purification processes. This product exhibits exceptional properties including high thermal conductivity, excellent insulation, high hardness, heat resistance, corrosion resistance, and wear resistance. It also demonstrates outstanding characteristics such as good fluidity, low oil absorption, high spheroidization rate, high α-phase content, small specific surface area, and controllable particle size distribution. It is widely used as a filler in thermal interface materials, thermal engineering plastics, and aluminum-based copper-clad laminates.
Spherical alumina, especially ultrafine spherical alumina powder, has regular morphology, large bulk density, good fluidity, high hardness and strength, and can be used to prepare substrates with excellent properties.
7. Application Industry Analysis of Spherical Aluminum Oxide:
Ø ceramic material
Spherical powders, with their regular morphology, higher bulk density, and excellent flowability, can significantly enhance the mechanical properties of ceramics. Therefore, incorporating a certain amount of spherical alumina powder during ceramic production can substantially improve ceramic performance. The low-temperature brittleness of ceramics severely limits their application scope, but ceramic materials with spherical alumina powder can be used to produce low-temperature resistant plastic ceramics. Moreover, spherical alumina can greatly improve ceramic toughness. When the powder content reaches 5.0%, it effectively enhances ceramic toughness and reduces sintering temperature.
Ø Important Materials in the Field of Catalysts and Their Carriers
Alumina exhibits high chemical reactivity due to its abundant unsaturated chemical bonds and numerous catalytic active sites. Moreover, spherical alumina offers distinct advantages including minimal particle wear, extended service life, and a large specific surface area. Consequently, catalysts and support materials fabricated from spherical alumina demonstrate unparalleled performance that other materials cannot match.
Ø polishing abrasive
Compared with the traditional granular or flake alumina, the spherical alumina has better dispersibility and fluidity, the powder abrasive can be evenly distributed in the polished product, and the phenomenon of abnormal powder accumulation does not occur.
Ø 3D printing materials
Spherical alumina is the most commonly used material for 3D printing due to its high strength, high sphericity, and heat resistance. Spherical alumina powder exhibits excellent particle fluidity, chemical reaction rate, and compactability, making it suitable for printing slurries with high solid content, good fluidity, easy cleaning, and superior mechanical properties.
