What occurs to radar absorbing material when it is exposed to extreme heat?

When radar absorbing material (RAM) is exposed to extreme heat, it typically expands and can create bubbles as its physical properties are altered under high-temperature conditions. The heat may cause the material to expand beyond its designed tolerances, resulting in deformations such as bubbling or warping. This change can compromise its effectiveness in absorbing radar waves, ultimately reducing the stealth characteristics that aircraft rely upon.

In contrast, the other options do not accurately describe the effects of extreme heat on radar absorbing materials. For instance, RAM does not become more efficient with heat exposure, nor does heating it enhance bonding of materials—it tends to weaken connections over time. Additionally, while changes in temperature can potentially affect color, heat does not specifically result in a loss of color in radar absorbing materials as a primary effect. Thus, the option referring to the expansion and creation of bubbles appropriately captures the impact of extreme heat on such materials.