Surmet Engineering Better Material Solutions

Environmental Durability for Reduced Non-Ballistic Failures

	Sand and debris kicked up in wind and rotor wash pose a serious threat to glass-based armor windows.

Sometimes the environment poses the biggest threat to transparent armor systems. Glass-based armor systems have a tendency to degrade due to non-ballistic phenomena such as rock strikes, sand erosion and prolonged UV exposure. These conditions can quickly impair the clarity and function of glass-based transparent armor. ALON® transparent armor, however, has proven to be exceptionally resistant to such conditions.

• Rock-Proof:  Kicked up rocks and large debris can cause significant damage to glass-based transparent armor windows; however, at the same size and thickness, Surmet’s ALON® ceramic can withstand granite rock strikes at over 4X the impact force required to shatter glass.
• Scratch-Proof:  The optical transmission of glass-based transparent armor has a tendency to degrade over time due to thousands of tiny scratched made by wind-swept sand and dust.  In controlled sand erosion testing, the optical transmission of glass-based armor reduced by 23% while the optical transmission of ALON® transparent armor remained the same.
• Delamination Resistant:  ALON® transparent armor has low interlaminar residual stresses due to a more compatible coefficient of thermal expansion (CTE) with both glass and polycarbonate.  Under thermal cycling, ALON® transparent armor has a much lower propensity for delamination than glass-based armor.
• Tolerant of Extreme Conditions:  ALON® transparent armor is an exceptionally high-performing material in extreme environmental conditions.  ALON® transparent armor has proven to withstand both mechanical stresses (vibration, mechanical shock, g-loading and sudden pressure release) and environmental stresses (solar radiation, humidity, temperature ranges from +185°F to -67°F and thermal cycling).