About one stable and three metastable eutectic microconstituents in the Fe–W–C system

Abstract

The Fe-W-C system has been the subject of numerous investigations and the findings have led to quite different interpretations in the iron-rich corner, justifying the need for new experimental studies. In the present study, some 12 compositions are prepared using both the powder metallurgy technique and the casting of melted alloys. DTA experiments, long time annealing supplemented by the phase separation technique and controlled solidification experiments are carried out. The micrographs of the corresponding specimens reveal significant sedimentation of WC carbides, an observation which must be carefully taken into account in interpreting the micrographs. The liquid/solid equilibria between 1423 and 1543 K are investigated and the corresponding partial isothermal sections of the Fe-W-C system are compared to the calculated phase equilibria based on thermochemical models. Four ternary eutectic microconstituents

Tungsten Carbide Supports for Single-Atom Platinum-Based Fuel-Cell Catalysts: First-Principles Study on the Metal–Support Interactions and O2Dissociation on WxC Low-Index Surfaces

“…In addition to hexagonal phase, WC also exists in cubic structure with the space group Fm 3̅ m . Cubic tungsten monocarbide (c-WC) is a high-temperature phase, which can be synthesized through rapid quenching process from its liquid state. , Apart from WC, W x C materials also exist as lower hexagonal carbides, W 2 C. These W-rich versions of the W x C structures are classified in four different modifications (polymorphs), which are denoted as α-, β-, γ-, and ε-W 2 C. The space groups for the four polymorphs of W 2 C are listed in Table . More detailed investigations on the W x C structures can be found in the works of Kurlov and Gusev. , …”

First-principles calculation on β-SiC(111)/α-WC(0001) interface

“…36 The electronic band structure and density of states show that the instability of NaCl-type structure is due to the occupation of anti-bonding states. 37 The bulk silicon carbide also has many structures, and the SiC fiber prepared by CVD method is usually b-SiC, which is a zinc blende crystal structure (similar to diamond).…”

Theoretical study on the stability, elasticity, hardness and electronic structures of W–C binary compounds

“…In addition to the hcp phase, WC also exists in the NaCl-type structure (c-WC). This is a high temperature phase and can be stabilized at room temperature by a rapid quenching process applied to the liquid state [15]. The c-WC is found to be superconducting with a transition temperature of 10.0 K [16], and the h-WC is more stable than the c-WC.…”