Influence of heating rate, temperature, pressure on the structure, and phase transition of amorphous Ni material: A molecular dynamics study

Abstract

The present article is aimed to investigate influence of the heating rate, temperature (T), pressure (P) on the structure and phase transition of amorphous Ni material with heating rate 2 Â 10 5 , 2 Â 10 6 and 2 Â 10 7 K/s at T ¼ 300 K; T ¼ 300, 400, 500, 600, 700, 800, 900 and 1000 K at heating rate 2 Â 10 6 K/s; T ¼ 300, 621 and 900 K at P ¼ 1, 2, 3, 4 and 5 GPa by molecular dynamics simulation method with Sutton-Chen embedded potential and periodic boundary conditions. The structure of amorphous Ni material determined through the radial distribution function, the total energy, the size and the average coordination number. The phase transition and the glass transition temperature determined through the relationship between the total energy and temperature. The result shows that when the heating rate increases, the first peak's position for the radial distribution function is 2.45 Å and a constant, the first peak's height, the total energy and the size increase, the average coordination number decreases from 13 to 12. When temperature increases from 300 to 1000 K at P ¼ 0 GPa, the position decreases from 2.45 Å to 2.40 Å, the average coordination number is 13 and a constant, glass transition temperature is 631 K, the total energy increases, the size increases and happens the phase transition from the amorphous state to the liquid state. When pressure increases from 0 GPa to 5 GPa at T ¼ 300, 621 and 900 K, the position decreases, the height increases, the total energy increases, the size decreases, the average coordination number decreases from 13 to 12, that shows with amorphous Ni material when increasing heating rate, T, P lead to structural change, phase transition of materials is significant.

Synthesis and Characterization of Polypyrrole Film Doped with Both Molybdate and Salicylate and Its Application in the Corrosion Protection for Low Carbon Steel

“…Nowadays, metals, alloys in general and low carbon steel (LCS) in particular, are the most common material widely used in all areas of economic and social life. Metals such as Ni, 1 , 2 Fe, 3 − 5 Al, 6 , 7 and Ag; 8 alloys such as FeCoNi, 9 CuAu, 10 Fe 2 O 3 , 11 AgAu, 12 FeC, 13 AlNi, 14 AuCu, 15 NiCu, 16 − 18 and NiFe; 19 , 20 nonmetallic polymers; 21 , 22 and polymer–metals 23 have good properties such as durability, fire protection, and good electrical conductivity. When metal or nonmetallic dopants are introduced into polymers, their conductivity increases.…”

“…Nowadays, metals, alloys in general and low carbon steel (LCS) in particular, are the most common material widely used in all areas of economic and social life. Metals such as Ni, , Fe, − Al, , and Ag; alloys such as FeCoNi, CuAu, Fe 2 O 3 , AgAu, FeC, AlNi, AuCu, NiCu, − and NiFe; , nonmetallic polymers; , and polymer–metals have good properties such as durability, fire protection, and good electrical conductivity. When metal or nonmetallic dopants are introduced into polymers, their conductivity increases. − Their highest disadvantage is that they can oxidize or corrode when they are exposed to the environment as microbial corrosion in petroleum and industrial wastewater, , the biodegradation of hydrocarbons, and the methanol extract from marine algae inhibit the corrosion ability of steel in sodium chloride medium .…”