Why can not diamond blade machining steel?
Dora Zhang
www. boreway. com
2017-12-25 18:50:49
Above 800 degrees Celsius, the diamond powder dissolves in iron. Use of diamond cutting tool turning iron material, as a result of friction heat, diamond dissolved in iron, the cutter occurred "knot" phenomenon, resulting in the tool can not continue to use.
This is determined by the crystal structure of diamond and iron. In the synthesis of diamond single crystal, the eighth group of metal elements Fe (iron), Co, Ni, Ru, Rb, Pd, Cs, Ir, Pt, Cr, Mn, Ta and other 12 kinds of elements can be used as catalyst material, Face-centered cubic or dense hexagonal structure. Among them, the lattice constants of the Fe, Fe, Co and Ni are closest to the lattice constant of diamond of 3.56 angstroms. Such a structure is most likely to convert graphite to diamond under high temperature and high pressure conditions.
This is determined by the crystal structure of diamond and iron. In the synthesis of diamond single crystal, the eighth group of metal elements Fe (iron), Co, Ni, Ru, Rb, Pd, Cs, Ir, Pt, Cr, Mn, Ta and other 12 kinds of elements can be used as catalyst material, Face-centered cubic or dense hexagonal structure. Among them, the lattice constants of the Fe, Fe, Co and Ni are closest to the lattice constant of diamond of 3.56 angstroms. Such a structure is most likely to convert graphite to diamond under high temperature and high pressure conditions.
However, under normal pressure conditions, graphite is steady state and diamond is metastable state. These elements have an anti-catalysis effect on diamond to convert diamond to graphite. Since iron (Fe) has the least d electrons, its affinity with carbon atoms is stronger, and Fe (iron) carbon forms stable Fe3C.
