A group of researchers from a Portuguese university developed an innovative method for manufacturing a new generation of closed-cell metal foams reinforced with nanodispersoids combining the powder technology method with colloidal processing. The invention respects to a product with excellent energy absorption capacity to impact and sound damping for vehicle applications, houses, machinery, equipment and devices with superior performance.
Main advantages of its use
The biggest advantages / benefits of the technology is to ensure the manufacture of closed-cell metal foams reinforced with nanodispersoids of high performance, significantly higher than that of current foams existing on the market. The present invention has the following advantages over existing technologies: granting new and multifunctional materials with high mechanical performance due to an efficient load transfer from the metallic matrix to the reinforcing elements.
The developed technology combines the advantages of lightweight closed-cell metal foams and nanodispersoids (e.g. Carbon nanotubes), both with remarkable properties. The metal foams, lightweight, recyclable, non-flammable and with excellent energy absorption capacity to impact and noise and vibration damping, are suitable for various commercial and military purposes. For example, as energy absorbing systems to impact on vehicles and ballistic protection systems for houses, vehicles / aircraft and personal protective equipment (e.g. Bullet proof vests).
On the other hand, taking the tremendous potential of nanodispersoids as mechanical reinforcement agents of metallic matrix without degrading their intrinsic properties allows improving the properties of traditional materials. The new method comprises three steps: (i) preparing spherical granules by freeze-granulation, followed by lyophilisation of a well-dispersed suspension containing all materials components involved (powders of metal and blowing agent, and carbon nanotubes) and processing additives; (ii) preparing a dense foamable precursor material by hot compaction of the granules; (iii) foam formation through controlled heating the precursor material.
Transports’ sector: lightweight systems for impact energy absorption and protection in vehicles.
Building construction sector: cladding panels for acoustic and thermal insulation of buildings and houses.
Sector of construction machinery and equipment: lightweight structural components for damping noise and vibrations;
Light modern furniture sector (e.g. tables, handles, lamp bases);
Military sector: lightweight ballistic protection structures for personal protective equipment (bullet-proof vests) and vehicles / aircraft.
Intellectual property status
Current development status
This invention is in the embryonic stage "Laboratory tests".
The first experimental results are very promising. It was possible to demonstrate the feasibility of the manufacturing of nanocomposite metal foams by incorporating in the matrix the nanodispersoid reinforcements uniformly distributed. The proposed method combines colloidal processing (based on freeze granulation, followed lyophilisation) and powder metallurgy method.
It has been shown that nanotubes can be well-dispersed in the initial suspension and that the level of homogeneity thus obtained is preserved during the whole process, allowing obtaining metal foams in which carbon nanotubes are non-agglomerated or damaged, and are stretched, maintaining their structural integrity in the metallic matrix of the resulting foam. Moreover, the results showed that the presence of multi-walled carbon nanotubes in the metallic matrix in this new generation of metal foams confer it enhanced mechanical properties. For example, the hardness of the foam matrix of such new foams (maximum value: HV = 135; mean value: HV = 93.43) is superior to the existing foams (mean = 60 HV).
Desired business relationship