What is a potential risk when drilling hole filling fasteners in composite materials?

When drilling hole filling fasteners in composite materials, the potential risk of delamination is particularly significant. Composite materials are made up of layers, often comprising woven fibers reinforced with resin. Drilling into these materials can lead to separation between the layers if not done correctly. This delamination weakens the integrity of the material, compromising its overall structural strength and performance.

When drilling, excessive heat or pressure can contribute to this issue, especially in areas where the material is already under stress or has defects. If delamination occurs, it can lead to significant problems, including loss of load-bearing capabilities and increased vulnerability to environmental factors, which are crucial considerations in aircraft structures.

The other potential risks, while valid concerns in their own right, do not specifically address the unique characteristics of composite materials in the same way delamination does. For instance, decreased material strength and improper fit are outcomes that can arise in various materials, not just composites, while improved weight distribution does not represent a risk associated with drilling holes in these structures. Thus, the emphasis on delamination aligns closely with the fundamental properties of composite materials and the specific challenges that arise during fabrication and maintenance processes.