Synthesis, crystal structure, and properties of stoichiometric hard tungsten tetraboride, WB₄

Abstract

Hard stoichiometric WB4 is synthesized under high-pressure and high-temperature conditions.

Effect of deposition pressure on friction and wear properties of BWS2 composite coatings

“…A portion of the W atoms is captured by B atoms, which makes some S atoms unable to combine with W to cause S loss and reduce the relative content of S elements in B/WS 2 composite coatings. Owing to its high hardness physical properties [34], the high content of WB 4 increases the hardness of B/WS 2 composite coatings, and the atomic radius of B is significantly different from that of W, S, and other elements, which easily produces lattice distortion, refines grains, and improves the hardness and elastic modulus of B/WS 2 composite coatings.…”

“…The analysis shows that, on the one hand, under a deposition pressure of 0.6 Pa, the WB 4 content was high during the sputtering process, the B/WS 2 composite coatings was dense (figure 2(a)), the coating had strong friction and wear resistance, and the coating wear life was long (6.8 × 10 4 cycles). This is due to the physical properties of the transition metal boride (WB 4 ), which has high hardness and strong wear resistance [34]. However, for the same deposition time, because the film thickness of the B/WS 2 composite coatings was only 0.96 μm (figure 3(a)), the B/WS 2 composite coatings failed to lubricate within a certain period, the wear life was not optimal.…”

A theoretical investigation on the structural stability, superconductivity, and optical and thermodynamic properties of Ir2P under pressure

“…4 Some promising candidates, such as OsB 2 , Ir 4 B 5 , ReB 2 , WB 4 , TaC, ReC, ReC 2 , Zr 3 N 4 , and Mo 3 N 5 have been experimentally synthesized and studied. [5][6][7][8][9][10][11][12][13] Firstprinciples density functional theory (DFT) calculations are a powerful tool for predicting the structural, electronic, elastic, and thermodynamic properties of carbides, nitrides and borides with transition-metal elements in a large region of the periodic table. [14][15][16][17][18][19][20][21][22][23] However, the study of transition-metal phosphides (TMPs), especially noble-metal phosphides, is relatively limited.…”