Carbon hexagonal lattice. As of 2009, graphene appears to be the strongest material ever tested. The process of separating it from graphite will require some further technological development before it is economical for industrial processes. If successful, graphene could be used in the construction of a space elevator. It could also be used to safely store hydrogen for use in a hydrogen based engine in cars. The amorphous form is an assortment of carbon atoms in a non-crystalline, irregular, glassy state, not held in a crystalline macrostructure. It is present as a powder, and is the main constituent of substances such
Diamond-like carbon various ways at the nanoscale level of structure, DLC coatings can be made that at the same time are amorphous, flexible, and yet purely sp bonded "diamond". The hardest, strongest, and slickest is such a mixture, known as tetrahedral amorphous carbon (ta-C). For example a coating of only 2 μm thickness of "ta-C" increases the resistance of common (e.g., type 304) stainless steel against abrasive wear, changing its lifetime in such service from one week to 85 years. Such "ta-C" can be considered to be the "pure" form of DLC, since it consists only of sp bonded carbon atoms. Fillers