New metal foam tougher than steel, could make safer cargo tankers

A recent study by researchers at North Carolina State University highlights the exceptional puncture and impact resistance of Composite Metal Foam (CMF), a lightweight material composed of a metallic matrix embedded with hollow spheres. CMF demonstrated the ability to withstand forces that would typically puncture steel railroad tank cars, which are used to transport hazardous materials such as acids, chemicals, petroleum, and liquefied natural gas. The material’s unique structure not only provides high strength and minimal weight but also offers superior heat resistance and insulation compared to steel, making it highly suitable for safety-critical applications in transportation and defense. In rigorous testing, a 30.48-millimeter-thick CMF layer placed on a steel plate prevented a 300,000-pound ram car’s six-inch steel indenter from puncturing the plate, absorbing nearly all the impact energy and causing only minor damage. This contrasted sharply with the significant hole created in the steel plate without CMF protection. The research team also developed a computational model to optimize CM