In recently published research, engineers at North Carolina State University have determined that composite metal foam (CMF) and epoxy resin can be combined to improve aircraft wing performance.
“Aluminum is currently the material of choice for making the leading edge of fixed-wing and rotary-wing aircraft wings,” said Afsaneh Rabiei, professor of mechanical and aerospace engineering at NC State. “Our results suggest that infused CMF may be a valuable replacement, offering better performance at the same weight.”
CMFs, which have survived fits and starts in development since their emergence in the mid-1920s, are mostly hollow metallic matrices built from materials like stainless steel and titanium. Lightweight CMFs perform very well in extreme conditions and have demonstrated the ability to withstand high temperatures, resist extreme blast pressures and even withstand the concussive force of a .50-caliber round.
Following on these remarkable characteristics, NC State engineers engineered their newest CMF with a bit of a twist. Rather than allowing the hollows in their CMF to remain empty, those cavities were filled with a hydrophobic epoxy resin, creating what engineers call an infused CMF.
When put through testing rigors, including contact angle exams, insect adhesion tests, and erosion sampling, NC State’s infused CMF outstripped traditional aluminum wing performance by a wide margin.
“Researchers found that infused CMF had a contact angle 130 percent higher than aluminum,” insect adhesion was down across several vectors, and “CMF retained its properties through erosion and wear, which indicates that it would give leading-edge wing components a longer lifetime and reduce the costs associated with maintenance and replacement.”
Though aluminum will continue to be the material of choice for aircraft manufacturers, as the industry trends toward lighterweight and possibly all-electric flyers, technologies like infused CMF wings might be a building block upon which a new generation of crafts emerge.