Formation and reactivity of borides, carbides and silicides. I. Review and introduction

Abstract

Borides, carbides and silicides are reviewed with special reference to newer production methods and fabrication techniques. Crystal structures and types of bonding in binary and ternary compounds are classified and discussed. The scope and limitations of the Pauling‐Rundle theory, molecular orbital treatment and the Ubbelohde‐Samsonov theory are examined critically and appropriate experimental evidence is summarised. Information so far available on the sintering of borides, carbides and silicides is summarised in relation to their chemical reactivity. The sintering is influenced by additives or impurities such as oxides formed by partial hydrolysis and oxidation. Resistance to oxidation is increased by sintering and hot pressing the refractories, but since the affinity of the metals is exclusively higher for oxygen, exchange reactions diminish the quality of the materials. Boride and carbide coatings generally have poor resistance in air or oxygen, but some silicides are more suitable. The kinetics and products of oxidation of borides, carbides and silicides so far studied depend mainly on the intrinsic reactivity of the material and the available surface at which oxidation can occur.

The evaluation Of The Non-Toxic Ferrous Matrix Based WC Reinforced Composites: A Review

“…They also reported that M23C6 type carbides for W-Fe-C systems are metastable at these temperature ranges. This occasion has been confirmed by other studies as well [6,7]. In another study, Upadhyaya [8] investigated the formation kinetics of Fe-containing MC, M6C, and M12C carbides in metal matrix composites.…”

“…This situation was confirmed by different studies. [6,7]. Hou, Linder [16], and C. B. Pollock [40] performance.…”

Effet de l’addition de TiB2 sur les propriétés mécaniques et tribologiques de revêtements NiCrBSi déposés par projection thermique

“…(Fig. 3c), les éléments Cr, Ni, Si, O et C ont été identifiés avec la possibilité de former des composés stables selon l'énergie libre de formation [18]. L'analyse EDS de la région 2 ( Fig.…”

“…D'autre part, le diborure de titane (TiB 2 ) peut être utilisé comme renfort pour les alliages autofondants à base de Ni, parce qu'ils présentent une dureté (18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) GPa) et une température de fusion (3225°C) très élevées [7]. L'addition de TiB 2 aux revêtements de NiCrBSi doit donc améliorer leur résistance à l'usure.…”

Unveiling the Changes of Dinickel Phosphide (Ni2P) in Hydrogen Evolution Reaction: Toward a Deeper Mechanistic Understanding

“…14−17 These metalrich phosphides are noted for their hardness, strength, and high thermal and chemical stability, akin to traditional metallic compounds such as carbides, nitrides, borides, and silicides. 18 They also exhibit excellent thermal and electrical conductivity. Unlike carbides and nitrides, metal-rich phosphides showcase distinct structural characteristics.…”