![]() Spinel structure of ALON
| |
Names | |
---|---|
Systematic IUPAC name
Aluminium oxynitride | |
Identifiers | |
Abbreviations | ALON |
Properties | |
(AlN)x·(Al2O3)1−x, 0.30 ≤ x ≤ 0.37 | |
Appearance | White or transparent solid |
Density | 3.691–3.696 g/ cm3 [1] |
Melting point | ~2150 °C [1] |
insoluble | |
Refractive index (nD)
|
1.79 [2] |
Structure | |
cubic spinel | |
a = 794.6 pm
[2]
| |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Aluminium oxynitride (marketed under the name ALON by Surmet Corporation [3]) is a transparent ceramic composed of aluminium, oxygen and nitrogen. Aluminium oxynitride is optically transparent (≥ 80%) in the near-ultraviolet, visible, and mid-wave- infrared regions of the electromagnetic spectrum. It is four times as hard as fused silica glass, 85% as hard as sapphire, and nearly 115% as hard as magnesium aluminate spinel. It can be fabricated into transparent windows, plates, domes, rods, tubes, and other forms using conventional ceramic powder processing techniques.[ citation needed]
Aluminium oxynitride is the hardest polycrystalline transparent ceramic available commercially. [2] Because of its relatively low weight, distinctive optical and mechanical properties, and resistance to oxidation or radiation, it shows promise for applications such as bulletproof, blast-resistant, and optoelectronic windows. [4] Aluminium oxynitride-based armor has been shown to stop multiple armor-piercing projectiles of up to .50 BMG. [5]
Aluminium oxynitride is resistant to various acids, bases, and water. [6]
Aluminium oxynitride has the following mechanical properties: [2]
Aluminium oxynitride has the following thermal and optical properties: [7]
Aluminium oxynitride is used for infrared-optical windows, with greater than 80% transparency at wavelengths below about 4 micrometers, dropping to near zero at about 6 micrometers. [8] It has also been demonstrated as an interface passivation layer in some semiconductor-related applications. [9]
Aluminium oxynitride has less than half the weight and thickness of glass-based transparent armor. [10] Aluminium oxynitride armor of 1.6-inch (41 mm; 4.1 cm) thickness is capable of stopping .50 BMG armor-piercing rounds, which can penetrate 3.7 inches (94 mm; 9.4 cm) of traditional glass laminate. [8] [11]
In 2005, the United States Air Force began testing aluminium oxynitride-based armor. [12]
Aluminium oxynitride can be fabricated as windows, plates, domes, rods, tubes and other forms using conventional ceramic powder processing techniques. Its composition can vary slightly: the aluminium content from about 30% to 36%, which has been reported to affect the bulk and shear moduli by only 1–2%. [13] The fabricated greenware is subjected to heat treatment (densification) at elevated temperatures followed by grinding and polishing to transparency. It can withstand temperatures of about 2,100 °C (2,370 K) in inert atmospheres. The grinding and polishing substantially improves the impact resistance and other mechanical properties of armor. [7]
Patents related to aluminium oxynitride include:
![]() Spinel structure of ALON
| |
Names | |
---|---|
Systematic IUPAC name
Aluminium oxynitride | |
Identifiers | |
Abbreviations | ALON |
Properties | |
(AlN)x·(Al2O3)1−x, 0.30 ≤ x ≤ 0.37 | |
Appearance | White or transparent solid |
Density | 3.691–3.696 g/ cm3 [1] |
Melting point | ~2150 °C [1] |
insoluble | |
Refractive index (nD)
|
1.79 [2] |
Structure | |
cubic spinel | |
a = 794.6 pm
[2]
| |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Aluminium oxynitride (marketed under the name ALON by Surmet Corporation [3]) is a transparent ceramic composed of aluminium, oxygen and nitrogen. Aluminium oxynitride is optically transparent (≥ 80%) in the near-ultraviolet, visible, and mid-wave- infrared regions of the electromagnetic spectrum. It is four times as hard as fused silica glass, 85% as hard as sapphire, and nearly 115% as hard as magnesium aluminate spinel. It can be fabricated into transparent windows, plates, domes, rods, tubes, and other forms using conventional ceramic powder processing techniques.[ citation needed]
Aluminium oxynitride is the hardest polycrystalline transparent ceramic available commercially. [2] Because of its relatively low weight, distinctive optical and mechanical properties, and resistance to oxidation or radiation, it shows promise for applications such as bulletproof, blast-resistant, and optoelectronic windows. [4] Aluminium oxynitride-based armor has been shown to stop multiple armor-piercing projectiles of up to .50 BMG. [5]
Aluminium oxynitride is resistant to various acids, bases, and water. [6]
Aluminium oxynitride has the following mechanical properties: [2]
Aluminium oxynitride has the following thermal and optical properties: [7]
Aluminium oxynitride is used for infrared-optical windows, with greater than 80% transparency at wavelengths below about 4 micrometers, dropping to near zero at about 6 micrometers. [8] It has also been demonstrated as an interface passivation layer in some semiconductor-related applications. [9]
Aluminium oxynitride has less than half the weight and thickness of glass-based transparent armor. [10] Aluminium oxynitride armor of 1.6-inch (41 mm; 4.1 cm) thickness is capable of stopping .50 BMG armor-piercing rounds, which can penetrate 3.7 inches (94 mm; 9.4 cm) of traditional glass laminate. [8] [11]
In 2005, the United States Air Force began testing aluminium oxynitride-based armor. [12]
Aluminium oxynitride can be fabricated as windows, plates, domes, rods, tubes and other forms using conventional ceramic powder processing techniques. Its composition can vary slightly: the aluminium content from about 30% to 36%, which has been reported to affect the bulk and shear moduli by only 1–2%. [13] The fabricated greenware is subjected to heat treatment (densification) at elevated temperatures followed by grinding and polishing to transparency. It can withstand temperatures of about 2,100 °C (2,370 K) in inert atmospheres. The grinding and polishing substantially improves the impact resistance and other mechanical properties of armor. [7]
Patents related to aluminium oxynitride include: