Accession Number ADA579865
Title Analysis of the Fragmentation of AlON and Spinel Under Ballistic Impact.
Publication Date May 2013
Media Count 12p
Personal Author E. Strassburger J. W. McCauley M. Hunzinger P. Patel
Abstract It has been demonstrated that significant weight reductions can be achieved, compared to conventional glass-based armor, when a transparent ceramic is used as the strike face on a glass-polymer laminate. Magnesium aluminate spinel (MgAl2O4) and AlON are promising candidate materials for application as a hard front layer in transparent armor. Comprehensive, systematic investigations of the fragmentation of ceramics have shown that the mode of fragmentation is one of the key parameters influencing the ballistic resistance of ceramics. In the study described here, the fragmentation of AlON and three types of spinel was analyzed: two types of fine grained spinel with nominal average grain sizes 0.6 lm and 1.6 lm and a bimodal grain-sized spinel with large grains of 250 lm size in a fine grain (5 20 lm) matrix were examined. The ceramic specimens of 6-mm thickness were glued to an aluminum backing and impacted with armor piercing (AP) projectiles of caliber 7.62mm at two different velocities 850 m/s and 1100 m/s. The targets were integrated into a target box, which allowed for an almost complete recovery and analysis of the ceramic fragments. Different types of high-speed cameras were applied in order to visualize the different phases of fragment formation and ejection. A laser light-sheet illumination technique was applied in combination with high-speed cameras in order to determine size and speed of ejected ceramic fragments during projectile penetration. The application of the visualization techniques allowed for the analysis of the dynamics of the fragment formation and interaction with the projectile. A significant difference in the fragment size distributions of bimodal grain-sized spinel and AlON was observed.
Keywords Alon
Alon(Aluminum oxynitride)
Ceramic materials
Grain size
High speed cameras
High-speed photography
Laser light-sheet technique
Magnesium aluminate spinel
Magnesium compounds
Weight reduction

Source Agency Non Paid ADAS
NTIS Subject Category 71D - Ceramics, Refractories, & Glass
79E - Detonations, Explosion Effects, & Ballistics
46E - Structural Mechanics
Corporate Author Army Research Lab., Aberdeen Proving Ground, MD. Weapons and Materials Research Directorate.
Document Type Journal article
Title Note Journal article.
NTIS Issue Number 1323
Contract Number N/A

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