Elastic Properties and Stacking Fault Energies of Borides, Carbides and Nitrides from First-Principles Calculations

Abstract

Owing to the excellent elastic properties and chemical stability, binary metal or light element borides, carbides and nitrides have been extensively applied as hard and low-compressible materials. Researchers are searching for harder materials all the time. Recently, the successful fabrication of nano-twinned cubic BN (Tian et al. Nature 493:385-388, 2013) and diamond (Huang et al. Nature 510:250-253, 2014) exhibiting superior properties than their twin-free counterparts allows an efficient way to be harder. From this point of view, the borides, carbides and nitrides may be stronger by introducing twins, whose formation tendency can be measured using stacking fault energies (SFEs). The lower the SFEs, the easier the formation of twins. In the present study, by means of first-principles calculations, we first calculated the fundamental elastic constants of forty-two borides, seventeen carbides and thirty-one nitrides, and their moduli, elastic anisotropy factors and bonding characters were accordingly derived. Then, the SFEs of the {111} < 112 > glide system of twenty-seven compounds with the space group F 4 3m or Fm3 m were calculated. Based on the obtained elastic properties and SFEs, we find that (1) light element compounds usually exhibit superior elastic properties over the metal borides, carbides or nitrides; (2) the 5d transitionmetal compounds (ReB 2 , WB, OsC, RuC, WC, OsN 2 , TaN and WN) possess comparable bulk modulus (B) with that of cBN (B = 363 GPa); (3) twins may form in ZrB, HfN, PtN, VN and ZrN, since their SFEs are lower or slightly higher than that of diamond (SFE = 277 mJ/m 2 ). Our work can be used as a valuable database to compare these compounds.

Defects in Titanium Aluminum Nitride-Based Thin Films

“…Shimizu et al [41] demonstrated that highly textured wurtzite Ti-Al-N phases can be grown at low temperatures using high power impulse magnetron sputtering (HIPIMS), resulting in coatings with excellent hardness (up to 35 GPa). Calamba et al [42] used UHV magnetron sputtering and an intermediary TiN (111) layer to grow metastable w-Ti1-xAlxNy, which showed segregation into Al-rich and Ti-rich domains. However, detailed high-resolution investigations of wurtzite structures, particularly before segregation occurs, have not been performed, leaving gaps in knowledge.…”

“…Transition metal nitrides are known to have extremely high stacking fault energies [111] and some studies have shown that the inducing the stacking faults and twins in these films can improve its mechanical properties [112]. Thus, the understanding and formation of stacking faults on TMN is of interest and could provide a new route to engineer the mechanical behavior of materials.…”

Phase relations, and mechanical and electronic properties of nickel borides, carbides, and nitrides from ab initio calculations

“…This combination of properties makes these materials highly desirable for a number of industrial applications. Specically, TMX, TMX 2 , and TMX 4 (X ¼ B, C, and N; TM-transition metal) possess comparable bulk moduli to that of superhard cubic-BN (400 GPa), such as ReB 2 , WB, OsC, RuC, WC, OsN 2 , PtN 2 , and WN, [1][2][3] and some of them have been put to the test and proved to be superhard materials, such as MoN, WB 4 , and FeB 4 . [4][5][6] High pressure enables not just the production of new polymorphic modications of known borides, carbides, and nitrides but also the synthesis of new compounds having stoichiometries not accessible at ambient pressure.…”

Corrosion Behaviors of Nitride Coatings on Titanium Alloy in NaCl-Induced Hot Corrosion

“…One effective technique to shield the alloy substrates from hot corrosion is to apply protective coatings such as metallic coatings (e.g., Al-based coatings, Nanocrystalline and NiCrAlY coatings) [7][8][9][10][11][12], ceramic coatings [13][14][15][16][17], enamel [14,18,19], silicon and silicide coatings [20][21][22][23][24][25][26], silicone-based composite coatings [27], and thermal barrier coatings [28][29][30]. Owing to the chemical inertness, well thermal stability, remarkable mechanical properties and similarity of the coefficients of thermal expansion in accordance with titanium alloy, nitride ceramic coatings including TiN and TiAlN are the promising approaches to protect titanium alloys against hot corrosion [31]. However, a huge number of works on corrosion resistance of TiN and TiAlN coatings are concentrated on the corrosion in aqueous solutions at room or low temperatures.…”