Graphenea researchers discovered that adding graphene to ceramic alumina can make it stronger - it is up to 50% less likely to break under strain. Graphenea's method is simple, fast and scalable, and it makes the alumina a hundred million times more conductive to electricity. Graphenea believes the same process will work for other ceramic materials such as silicon carbide, silicon nitride, titania, and zirconia.
A single graphene sheet bridges a crack in alumina
Graphenea's new process starts with graphene oxide - which is mixed with aluminium oxide (alumina) , and then they use a process known as spark plasma sintering (SPS, which drives a large electrical current through the material) to homogenize the graphene/alumina mixture. It was found that adding just 0.22% of graphene to alumina makes it 50% more resistant to the propagation of cracks under strain. Other mechanical properties stayed on par with untouched alumina, while electrical conductivity increased by a factor of a hundred million.
The graphene sheets align perpendicular to the direction of the SRS current (as can be seen above). Those graphene sheets then act as shields, stopping any cracks that propagate along that direction.
