Iron boride containing

Cementite, FeaC, has an interesting structure, involving both octahedral and trigonal-prismatic arrangements of six iron atoms about a carbon atom (Slrukiurbericht, II, 33). The iron boride FeB (Struktur-bericht, III, p. 12) contains trigonal prisms of iron atoms about the boron atoms, the Fe—B distance being about 2.15 A, which is approxi-... 

The formation of iron borides with metal nuclearity > 6 has been achieved by the Fehlner group,but, as in the RU7 and Rug clusters cited above,the actual cavity containing the boron atom is a hexametal one. The results of a crystallo-... 

Metal organic chemical vapor deposition (MOCVD) is a well-established, practical technique for forming simple as well as complex solid state films (130). For binary systems the conventional approach is to use mixtures of the most readily available molecules containing the elements of interest. This approach has been employed to prepare borides of several types. For example, iron-boron alloys have been pre-... 

Table 2 summarizes the best data obtained in three groups of alloys namely binary, ternary and complex alloys with combined strengthening with borides and silicides. The binary alloys is practically quasi-binary ones because contain enough content of iron, which transforms these formally alpha-alloys into practical pseudo-alpha ones containing small but important amount of beta-phase. 

Auger electron spectroscopy and secondary ion mass spectroscopy were used to study the interaction of polycrystalline p-BN samples (Kiborit) with weld-surfaced iron alloys. The wear loss was found to be higher and TiN and TiBg were formed if a titanium-containing alloy was machined. Borides, nitrides, and carbides of the alloying metals, especially of Cr, have also been detected [41]. 

Boron carbide is chemically inert, although it reacts with oxygen at elevated temperatures and with white hot or molten metals of the iron group, and certain transition metals. B4C reacts with halogens to form boron halides—precursors for the manufacture of most nonoxide boron chemicals. B4C also is used in some reaction schemes to produce transition metal borides. Boronizing packings containing B4C are used to form hard boride surface layers on metal parts. 

The alloy magnets Nd Fej B and SmCo are prepared by heating the elements at very high temperature. Iron neodynuum boride magnet alloys from Santoku (Molycorp) contain considerable Pr and Dy as well to inhibit corrision and enhance magnetism respectively. 

The ternary system has gained attention of materials scientists due to its potential for the development of iron (steel) matrix composites, thermochemical boriding of Cr containing steels and chromium boride coating on steels, amorphous/nanocomposite and magnetic materials. Therefore phase equilibria were extensively studied. An overview of the results of these investigations are presented in Table 1. 

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