High Strength Ni-Fe-W and Ni-Fe-W-P Alloys Produced by Electrodeposition

Abstract

Ni-Fe-W alloys were produced by electrodeposition from an ammoniacal citrate bath having nickel sulphate, ferric sulphate and sodium tungstate as sources of nickel, iron and tungsten, respectively. The alloys prepared at low current densities have nanocrystalline structure, while those prepared at high current densities are amorphous. X-ray diffraction results show that the structure changes gradually from nanocrystalline to amorphous phase with an increase of current density. As the current density increases, tungsten content increases while iron content decreases. The hardness of the alloys increases with increasing tungsten content. The best mechanical properties among all the alloys are obtained for 51Ni-29Fe-20W alloy prepared at 600 A/m 2 . Effect of sodium hypophosphite on the composition of the alloys produced at 2000 A/m 2 was also studied. Addition of hypophosphite causes a decrease in tungsten content of the alloys. Further increase in the hypophosphite content causes a decrease of both iron and tungsten contents and an increase of phosphorus and nickel contents. For the alloys deposited from solutions containing sodium hypophosphite more than 0.03 mol/L, the total molar content of tungsten and phosphorus remains constant at 20 at%.

From superhydrophobic- to superhydrophilic-patterned poly(vinylidene fluoride-co-chlorotrifluoroethylene) architectures as a novel platform for biotechnological applications

“…It is influence by various factors such as the surface energy of the material, the surface roughness, and the surface tension of the liquid. 26 Static contact angles of the flat and patterned P(VDF-CTFE) microstructures are presented in Figure 4. The fitting mode used for the measurement of the contact angles is of major importance since for the same water droplet different contact angles can be obtained.…”

Effect of argon plasma treatment on hydrophilic stability of nanofiber webs

“…Plasma is an effective grafting method for nanofibrous materials, and researchers have found that plasma treatment is useful for the formation of a hydrophilic layer on a hydrophobic base membrane, or vice versa. [24][25][26][27][28][29][30] Despite the benefits, the stability of the plasma treatment is still an open question. Gancarz et al 31 observed that the surface of a polysulfone membrane changed during the first week after nitrogen plasma treatment; some groups disappeared, and some others shifted toward the surface.…”

Control of Composition and Properties of Binary and Ternary Electrolytic Tungsten Containing Coatings

“…По-третє, в поточний час у світовій практичній гальванотехніці спостерігається майже безальтернативний перехід до багатокомпонентних і синергетичних сплавів, яким притаманне нададитивне посилення функціональних властивостей по відношенню до сплавотвірних компонентів. Серед практично важливих сплавів чільне місце посідають електролітичні композиції, утворені металами тріади заліза (залізо, кобальт і нікель) [1,2], а також їх сплави з тугоплавкими металами, в першу чергу вольфрамом і молібденом [3][4][5][6][7]. Одна з причин такої уваги полягає в тому, що індивідуальні покриви тугоплавкими металами з водних розчинів отримати неможливо, тоді як з металами родини заліза вони можуть спів осаджуватися у різноманітні сплави [8][9][10][11].…”