An incredible chemical transformation

2001/10/03 Roa Zubia, Guillermo - Elhuyar Zientzia

• Materialak
• Kimika

Boruros, carbides and siliciuros are very resistant and valuable materials for the machine tool industry. On the other hand, they have very special thermal properties. The main industrial application of silicon is, for example, the manufacture of boiler heater coils.

However, obtaining silicide is a slow and laborious process, since the material must be injected into the molds at very high temperatures and let cool slowly. In order to accelerate this long process, scientists from the University of Hannover began to investigate new ways of silicicium. Thus, in one experiment, they left the iron coil in the atmosphere of silicon tetrachloride, obtaining an unexpected result.

Silicide arose and, contrary to what was expected, the piece was not sprayed, but maintained its appearance and size without significant changes. The silicon atoms of the gas reacted with the surface of the solid modifying its chemical structure. The resulting material is porous, so the silicon came into the structure and transformed it. In the end they obtained an initial solid, completely changing the chemical structure. The solid became even more fragile than the original, but by heat treatment the necessary consistency can be given.

The piece used in the experiment was very fine, but scientists believe that if we let it react longer, with larger pieces, the process will also be effective.